To: Administrative File: CAG-00250R3
From: Louis Jacques, MD
Director, Coverage and Analysis Group
Tamara Syrek Jensen, JD
Deputy Director, Coverage and Analysis Group
Jyme Schafer, MD, MPH
Director, Division of Medical and Surgical Services
Lori Paserchia, MD
Lead Medical Officer
Lead Health Policy Analyst
Subject: Decision Memorandum for CAG #00250R3
Reconsideration of Facility Certification Requirement for Coverage of Covered Bariatric Surgery Procedures
Date: September 24, 2013
The Centers for Medicare & Medicaid Services (CMS) has determined that the evidence is sufficient to conclude that continuing the requirement for certification for bariatric surgery facilities would not improve health outcomes for Medicare beneficiaries. Therefore, CMS has decided to remove this certification requirement.
CMS also decided that no changes be made to the bariatric surgery procedures that are deemed covered in section 100.1 of the National Coverage Determination (NCD) Manual. The evidence continues to support that open and laparoscopic Roux-en-Y gastric bypass (RYGBP), laparoscopic adjustable gastric banding (LAGB), and open and laparoscopic biliopancreatic diversion with duodenal switch (BPD/DS) continue to be reasonable and necessary for Medicare beneficiaries who have a body-mass index (BMI) ≥ 35, have at least one co-morbidity related to obesity, and have been previously unsuccessful with medical treatment for obesity.
Lastly, we decided to change the title to better reflect the scope of the NCD and to make it clear in the manual that under the existing policy the local Medicare Administrative Contractors have the authority to make coverage decisions for certain patients for any bariatric surgery procedures not specifically identified as covered or non-covered by an NCD.
In addition, to the decision above, CMS is renumbering and consolidating its manual for section 100.1. This is an administrative change only to make it easier for the public to read and understand the NCD manual.
There is no change in coverage because of the renumbering and consolidation.
- The additional NCDs related to bariatric surgery will be consolidated and subsumed into section 100.1 of the NCD Manual. These include sections 40.5, 100.8, 100.11 and 100.14.
The changes to the manual are reflected in attachment Appendix C.
The following acronyms are used throughout this document. For the readers convenience they are listed here in alphabetical order.
ACS - American College of Surgeons
AHRQ - Agency for Healthcare Research and Quality
ASMBS - American Society for Metabolic and Bariatric Surgery
BMI - body-mass index
BSCOE - Bariatric Surgery Center of Excellence
CE - composite event
CI – confidence interval
COE - center of excellence
CVA- cerebrovascular accident
DD – difference-in-difference
DGR - diagnosis-related group
DVT - deep vein thrombosis
LABS - Longitudinal Assessment of Bariatric Surgery
LAGB - laparoscopic adjustable gastric banding
LRYGB - laparoscopic Roux-en-Y gastric bypass
MBSAQIP - Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program
MBSC – Michigan Bariatric Surgery Collaborative
NCA - National Coverage Analysis
NCD - National Coverage Determination
NIDDK - National Institute of Diabetes, Digestive and Kidney Diseases
NIH - National Institutes of Health
OR - odds ratio
ORYGB - open Roux-en-Y gastric bypass
ResDAC - Research Data Assistance Center
RR – relative risk
RYGB - Roux-en-Y gastric bypass
SD -standard deviation
SG - sleeve gastrectomy
SRC - Surgical Review Corporation
TAVR - Transcatheter Aortic Valve Replacement
UHC - University HealthSystem Consortium
The scope of this national coverage analysis (NCA) includes a review of the evidence on whether the facility certification requirement continues to improve outcomes for covered bariatric surgery procedures in the Medicare population. CMS also plans to make a number of administrative changes to the NCD. These administrative changes are further explained in section III.A of this document. We believe these administrative changes will make referencing the NCD on bariatric surgery easier for the public.
In February 2006, CMS completed a reconsideration of a national coverage determination (NCD) for bariatric surgery and published a final decision memorandum, which is available at http://www.cms.gov/medicare-coverage-database/details/nca-decision-memo.aspx?NCAId=160.
The requestors for that 2006 reconsideration had asked that Medicare cover numerous bariatric surgical procedures. CMS performed a review of the available evidence at that time and ultimately concluded that the evidence supported coverage for certain procedures and not for others. However, the coverage decision also specified, “CMS has determined that covered bariatric surgery procedures are reasonable and necessary only when performed at facilities that are: (1) certified by the American College of Surgeons (ACS) as a Level 1 Bariatric Surgery Center (program standards and requirements in effect on February 15, 2006); or (2) certified by the American Society for Bariatric Surgery as a Bariatric Surgery Center of Excellence (BSCOE) (program standards and requirements in effect on February 15, 2006) (CMS Bariatric Surgery 2006).”
In the review and analysis of the evidence at that time, CMS identified several facility and physician criteria that were believed to be essential for optimizing outcomes for bariatric surgery. These criteria focused on the competency of surgeons, training and experience that met national standards and training and experience in managing morbidly obese patients prior to, during and following surgery. There was a rapid increase in the rate of bariatric surgery procedures at that time, resulting in a need to establish practice standards (Livingston 2004). We found that both the ACS and the American Society for Bariatric Surgery (currently the American Society for Metabolic and Bariatric Surgery (ASMBS)) had existing certification programs in place that met or exceeded the criteria outlined in the decision memorandum of 2006.
The facility certification requirement that CMS established in the 2006 decision was supported by the evidence at that time of rapid growth of bariatric surgery programs, improved outcomes in the older Medicare population at higher volume facilities and with higher volume surgeons (Flum 2005) and by consensus opinion for the need for facility standards from the professional societies and other physicians in comments submitted in response to the proposed decision memorandum for bariatric surgery (CMS Bariatric Surgery 2006). Commenters supported the certification requirement, including a volume requirement, as documented in supporting comments provided through the public comment process on the proposed decision memorandum (CMS Bariatric Surgery 2006). CMS has now been asked to reevaluate this facility certification requirement. While CMS established a requirement for facility certification, often this is referred to as a center of excellence (COE) program.
III. History of Medicare Coverage
In 2006, CMS established a National Coverage Determination (NCD) on Bariatric Surgery for the Treatment of Morbid Obesity (NCD Manual Section 100.1 http://www.cms.gov/Regulations-and-Guidance/Guidance/Manuals/downloads/ncd103c1_Part2.pdf). For Medicare beneficiaries who have a BMI ≥ 35, have at least one co-morbidity related to obesity, and who have been previously unsuccessful with medical treatment for obesity, the following procedures were determined to be reasonable and necessary:
- open and laparoscopic Roux-en-Y gastric bypass (RYGBP);
- laparoscopic adjustable gastric banding (LAGB); and
- open and laparoscopic biliopancreatic diversion with duodenal switch (BPD/DS).
In addition, the NCD stipulates that these bariatric procedures are covered only when performed at facilities that are: (1) certified by the American College of Surgeons (ACS) as a Level 1 Bariatric Surgery Center or (2) certified by the American Society for Bariatric Surgery as a Bariatric Surgery Center of Excellence (BSCOE) (Program Standards and requirements in effect on February 15, 2006). The 2006 NCD specifically non-covered open vertical banded gastroplasty, laparoscopic vertical banded gastroplasty, open sleeve gastrectomy, laparoscopic sleeve gastrectomy, and open adjustable gastric banding because there was a paucity of evidence to support claims of improved health outcomes from those procedures.
In 2009, CMS reconsidered the NCD to include type 2 diabetes mellitus as a co-morbidity.
In June 2012, CMS reconsidered the NCD specifically regarding the laparoscopic sleeve gastrectomy (LSG) procedure and determined Medicare Administrative Contractors acting within their respective jurisdictions may determine coverage of stand-alone laparoscopic sleeve gastrectomy (LSG) for the treatment of co-morbid conditions related to obesity in Medicare beneficiaries only when all of the following conditions A-C are satisfied.
- The beneficiary has a body-mass index (BMI) ≥ 35 kg/m2,
- The beneficiary has at least one co-morbidity related to obesity, and
- The beneficiary has been previously unsuccessful with medical treatment for obesity.
A. Current Reconsideration
CMS received a formal request from Dr. John Birkmeyer, Dr. Nancy Birkmeyer and Dr. Justin Dimick asking for a reconsideration of the NCD on bariatric surgery, specifically requesting that CMS abandon the requirement for facility certification/COE designation.
CMS opened this national coverage analysis (NCA) to review the evidence on whether certification of bariatric surgery facilities improves outcomes in Medicare beneficiaries who undergo a currently covered bariatric surgery procedure.
At this time, we also plan to make a number of changes to section 100.1 of the NCD Manual. These changes include changing the title to clearly reflect the scope of the bariatric surgery NCD and adding a statement to make it clear in the manual that under the existing policy the local Medicare Administrative Contractors have the authority to make coverage decisions for any bariatric surgery procedures not specifically identified as covered or non-covered by an NCD. In addition, we plan at this time to consolidate all of the bariatric surgery NCDs by subsuming related sections 40.5, 100.8, 100.11 and 100.14 into section 100.1. This is an administrative change and there is no change in the coverage due to the consolidation. We believe this administrative change will make it easier for the public to access our policy on bariatric surgery.
B. Benefit Category
Medicare is a defined benefit program. An item or service must fall within a benefit category as a prerequisite to Medicare coverage. An item or service must meet one of the statutorily defined benefit categories in the Social Security Act and not otherwise be excluded.
Under 1861(s)(1) bariatric surgery qualifies as a(n)
- physician service,
- inpatient hospital services, and
- incident to a physician's professional service.
Note: This may not be an exhaustive list of all applicable Medicare benefit categories for this item or service.
IV. Timeline of Recent Activities
|| CMS initiates this national coverage analysis. Initial public comment period opens.
||Initial public comment period closes.
|| Telephone conference with leadership of ASMBS.
|| Proposed decision memorandum posted.
|| Second comment period closes.
|| Telephone conference with leadership of ASMBS.
V. Food and Drug Administration (FDA) Status
Various devices used in a bariatric surgery may fall under FDA regulatory oversight. However, our review is focused on the evidence for the CMS requirement for certification rather than FDA approval or clearance of a specific device. We continue to expect that those covered bariatric surgeries that include a device will only use devices that have been approved or cleared by FDA.
VI. General Methodological Principles
When making national coverage decisions under §1862(a)(1)(A), CMS generally evaluates relevant clinical evidence to determine whether or not the evidence is of sufficient quality to support a finding that an item or service falling within a benefit category is reasonable and necessary for the diagnosis or treatment of illness or injury or to improve the functioning of a malformed body member. The critical appraisal of the evidence enables us to determine to what degree we are confident that: 1) the specific assessment questions can be answered conclusively; and 2) the intervention will improve health outcomes for patients. An improved health outcome is one of several considerations in determining whether an item or service is reasonable and necessary.
A detailed account of the methodological principles of study design that the agency utilizes to assess the relevant literature on a therapeutic or diagnostic item or service for specific conditions can be found in Appendix A. In general, features of clinical studies that improve quality and decrease bias include the selection of a clinically relevant cohort, the consistent use of a single good reference standard, and the blinding of readers of the index test, and reference test results. Public comments sometimes cite the published clinical evidence and give CMS useful information. Public comments that give information on unpublished evidence such as the results of individual practitioners or patients are less rigorous and therefore less useful for making a coverage determination. Public comments that contain personal health information (PHI) will be redacted and the PHI will not be made available to the public. CMS uses the initial public comments to inform its proposed decision. CMS responds in detail to the public comments on a proposed decision when issuing the final decision memorandum.
In this NCD reconsideration, we reviewed evidence generated since we established the facility certification requirement in 2006. In reviewing the evidence, we focused on reports of analyses that compared outcomes in facilities that met those standards compared to facilities that did not meet those standards. We are concerned with short-term as well as long-term mortality and morbidity outcome rates in Medicare beneficiaries.
B. Literature Search
CMS performed its most recent literature search using PubMed on August 22, 2013 with the search terms “bariatric” and “center of excellence.” The following limitations were applied: Humans, Clinical Trial, English and Publication Date from 01/01/2006 to 08/22/2013.
C. Discussion of Evidence Reviewed
The question of interest for this NCA is:
Is the evidence sufficient to conclude that facility certification (sometimes referred to as a COE designation) improves meaningful health outcomes for Medicare beneficiaries who undergo a covered bariatric surgery?
2. External technology assessment (TA)
An external TA was not commissioned.
3. Internal technology assessment
Three articles (Livingston 2009; Birkmeyer 2010; Dimick 2013) were submitted by the requester. The CMS literature search identified two of the articles submitted by the requester (Livingston and Birkmeyer) and two additional articles (Kwon 2012 and Kohn 2010). Two articles (Nguyen 2010; Flum 2011) were identified during a search of the bibliographies of other articles and one additional article (Nguyen 2012) was identified by public commenters. One article (Nguyen 2013 cited as Jafari et al. 2013) was submitted after the second public comment period. All nine articles are reviewed below.
Livingston EH. Bariatric surgery outcomes at designated centers of excellence vs nondesignated programs. Arch Surg 2009;144:319-325.
The author performed an analysis of data from the 2005 National Inpatient Survey, which is a population-representative sampling of hospital discharges obtained from 20% of all hospitalizations in the U.S. each year. The National Inpatient Survey is maintained by the Agency for Healthcare Research and Quality (AHRQ). Bariatric procedures were found by identifying diagnosis related group (DRG) code 288, which is used when the primary reason for hospitalization is for procedures for morbid obesity. The designation of COE was made by visually matching the list of hospitals included in the 2005 National Inpatient Survey and the list of COEs identified on the CMS website. The outcomes of interest were in-hospital mortality and complications; a complication was defined by use of the National Inpatient Survey clinical classification software diagnostic variable 238, which states “complication of surgical procedures or medical care.” Expected mortality was also calculated. Long term outcomes were not evaluated. Logistic regression was performed “to assess the effect of COE status and annual hospital procedure volume on bariatric procedure morbidity and mortality. In-hospital death was the dependent variable, and COE status, annual procedure volume, age and male sex were also entered into the regression equations.”
At the time of the analysis, the National Inpatient Survey database listed 253 hospitals; 24 (9.5%) of these were designated as a COE. The CMS website listed 317 COEs during this time hence the analysis included 7.6% of the CMS-identified COEs. A total of 24,783 bariatric procedures were performed in the 253 hospitals included in the analysis; 5420 (28%) of these procedures were performed in a COE.
The mean (SD) age was 42.9 (11.2) for the patients treated in a COE and 42.4 (10.7) for the patients treated in a non-COE. Patients greater than 65 years of age comprised 1.3% of patients in the COE group and 1.8% of patients in the non-COE group. Medicare-enrolled patients comprised 8.3% of the COE group and 8.0% of the non-COE group. Information about the BMI or the specific types of bariatric procedures performed was not reported.
The author reported that the “mean number of cases performed per facility was substantially greater for COEs than for the hospitals that were not COEs.” The hospital mortality rate was 0.17% in COEs and 0.09% in non-COEs (difference not statistically significant).
The complication rate was 6.3% in COEs and 6.4% in non-COEs (difference not statistically significant). After logistic regression modeling it was stated, “Procedure volume was inversely related to complication rates, where as patient age and teaching hospital status were positively associated with postoperative complications.” Upon further regression modeling, the author noted that “As hospital volumes decrease, the expected complication rate increases with profound expansion of the CIs [confidence interval] as the volumes become very low. There are approximately as many hospitals above the 95% CIs as there are below them, suggesting that hospitals may exhibit higher or lower than expected complication rates irrespective of their procedure volume status.” In addition, further analysis of the effect of arbitrarily assigning hospital volume to predefined categories found that “Bariatric procedures conducted at hospitals performing fewer than 125 cases per year would appear to have an 18% greater likelihood of being associated with complications.”
The author noted some limitations to his analysis including the fact that the sampling of COEs was only 7.6% of the total number of existing COEs. The author commented, “I found that COEs perform substantially more bariatric procedures than non-COEs, yet both had commensurate outcomes. These findings suggest that the much larger number of hospitals that perform low volumes of bariatric procedures have outcomes similar to the high-volume COEs.”
Nguyen NT, Hohmann S, Slone J, Varela E, Smith BR and Hoyt D. Improved bariatric surgery outcomes for Medicare beneficiaries after implementation of the Medicare national coverage determination. Arch Surg 2010;145:72-78.
Nguyen and colleagues conducted a retrospective analysis of the University HealthSystem Consortium database, which contains administrative, clinical and financial data. The University HealthSystem Consortium is an alliance of 102 U.S. academic medical centers and approximately 150 affiliated hospitals. Discharge data for “all Medicare and Medicaid patients who underwent open or laparoscopic Roux-en-Y gastric bypass, laparoscopic biliopancreatic diversion with duodenal switch for the treatment of morbid obesity from October 1, 2004 to September 31, 2007” were analyzed as were the data for dual eligible patients. The goal of the analysis was to compare the outcomes and volumes of bariatric procedures performed on Medicare beneficiaries during the 18 months prior to and then during the 18 months after the 2006 NCD issued by CMS. Outcomes assessed were in-hospital mortality, peri-operative complications and observed-to-expected mortality ratio. Long term outcomes were not evaluated. Differences were determined using the Pearson chi-square test.
A total of 6264 Medicare and Medicaid patients who met the study criteria underwent bariatric surgery for the treatment of morbid obesity; 3196 patients before the NCD and 3068 patients after NCD implementation. Sixty institutions performed bariatric surgery before NCD implementation and 45 after NCD implementation. The authors noted that “More than half of the patients were between 31 and 50 years of age (51.6% before the NCD and 49.9% after the NCD). There were significantly more individuals greater than 65 years of age within the group after the NCD implementation (7.5% vs 9.6%, P < 0.05).” In addition, the “proportions of patients with diabetes, hypertension, congestive heart failure, liver disease, and chronic pulmonary disease were not significantly different between the 2 groups.” Information regarding the BMI was not reported. Before the NCD, 82.5% of the patients were women while after the NCD 81.5% were women. After implementation of the NCD, “there was a doubling in the volume of laparoscopic gastric banding (231 vs 489 procedures), with a decrease in the volume of gastric bypass (2714 vs 2403 procedures); however, the proportion of laparoscopic gastric bypass procedures increased from 60.0% before the NCD to 77.2% after the NCD.”
Regarding outcomes, the authors reported that “Compared with Medicare patients who underwent bariatric surgery before the NCD, patients who underwent bariatric surgery after the NCD had a lower overall complication rate (14.6% vs 10.4%; OR, 1.48; 95% CI, 1.21 – 1.82) and significantly lower rates of postoperative pulmonary complications (2.9% vs 1.7%; OR, 1.76; 95% CI, 1.10 – 2.82), wound infections (1.6% vs 0.7%; OR, 2.16; 95% CI, 1.10 – 4.25), and venous thrombosis or pulmonary embolisms (1.4% vs 0.6%; OR, 2.24; 95% CI, 1.07 – 4.67). No significant difference was seen in in-hospital mortality between groups (0.38% before the NCD vs 0.24% after the NCD). There was a trend toward improvement of the observed-to-expected mortality ratio from 1.07 before to 0.89 after implementation of the NCD.” Of note, the relevant table in the article reported that in-hospital mortality was 0.3% rather than 0.24% as reported in the above quote.
In addition the authors stated, “The group before implementation of the NCD had more patients with a higher severity of illness. To eliminate this important confounding variable, we examined the outcomes of bariatric surgery specifically within a subset of patients with major and extreme (higher) severity of illness. Compared with Medicare and Medicaid patients with major or extreme severities of illness who underwent bariatric surgery before the NCD, patients who underwent bariatric surgery after the NCD had a lower overall complication rate (50.1% vs 40.2%; OR, 1.50; 95% CI, 1.09 – 2.07). In addition, because there is an increase in the number of laparoscopic gastric banding procedures after implementation of the NCD, we examined specifically the outcomes of laparoscopic and open gastric bypass procedures performed before and after implementation of the NCD. After implementation of the NCD, Medicare patients (excluding Medicaid patients) who underwent laparoscopic or open gastric bypass benefited from a shorter length of hospital stay and lower overall pulmonary complication rates.”
Nguyen et al. addressed several limitations of their study: “The data derived from the UHC only represent in-hospital outcomes without follow-up data. Although data with regard to readmission to the same hospital are identified, any complications or deaths occurring during readmission to a different institution are not captured. The UHC database does not have the patients’ weights or body mass indexes for all patients, and these are important factors in computing risk adjustment of outcomes. In addition, the coding of certain complications may be inaccurate because postoperative adverse events can be subjectively defined and may be coded differently (eg, leaks). However, in-hospital mortality and length of stay are accurate end points because they do not require subjective interpretation. This study is also limited to academic centers, and the results may not be generalizable to nonacademic institutions.”
The authors concluded, “the outcomes have improved since the implementation of the Medicare bariatric surgery NCD. Since the implementation of the NCD, the volume of bariatric procedures remained the same, whereas the number of institutions caring for morbidly obese patients decreased from 60 to 45. Concurrently, there was a doubling of laparoscopic gastric banding procedures and an increase in the proportion of laparoscopic gastric bypass procedures from 60.0% to 77.2%. Implementation of the NCD did not impede access to care because the volume of bariatric procedures performed on Medicare beneficiaries returned to baseline volume within 1 year after the NCD implementation and exceeded the baseline volume at 2 years after the NCD implementation.”
Birkmeyer NJ, Dimick JB, Share D, Hawasli A, English WJ, Genaw J, Finks JF, Carlin AM, Birkmeyer JD; Michigan Bariatric Surgery Collaborative. Hospital complication rates with bariatric surgery in Michigan. JAMA 2010;304:435-442.
Birkmeyer et al. performed an analysis of data from the Michigan Bariatric Surgery Collaborative (MBSC) registry “to assess complication rates of different bariatric procedures and variability in rates of serious complications across hospitals and according to procedure volume and center of excellence (COE) status.” The registry contained data voluntarily submitted from 25 hospitals that performed at least 25 bariatric procedures per year. Data for the registry were collected by medical chart review. All patients undergoing bariatric surgery from June 2006 to September 2009 (n = 15,275) were included. Patients undergoing revisional surgery or duodenal switch procedures were excluded. The primary outcome was occurrence of a serious complication within 30 days of surgery, which was defined as potentially life-threatening or resulting in death or disability. Long term outcomes were not evaluated. The authors selected annual hospital and surgeon volume categories “using a combination of generally accepted volume cut points and empirical derivation based on the distribution of patients, hospitals, and surgeons. Sites were
deemed centers of excellence if they were designated as such by the American College of Surgeons or the American Society of Metabolic and Bariatric Surgeons at any point during our study period.” Three categories were selected: Low (mean annual surgeon procedure volume of < 100 or mean annual hospital procedure volume of < 150; Medium (mean annual surgeon procedure volume of 100 - 249 or mean annual hospital procedure volume of 150 - 299); High (mean annual surgeon procedure volume of ≥ 250 or mean annual hospital procedure volume of ≥ 300).
Median age was 46 years and there were no reported patients 60 years of age or older. Median BMI was 46 kg/m2. Men comprised 21% of the population. There were 854 sleeve gastrectomy (SG) procedures, 5380 laparoscopic adjustable gastric band procedures and 9041 open or laparoscopic gastric bypass procedures. Thirty-three (53%), 22 (36%) and 7 (11%) surgeons were in the low, medium and high volume categories, respectively. Ten (40%), nine (36%) and six (24%) hospitals were in the low, medium and high volume categories, respectively. Six of 10 low-volume hospitals, eight of nine medium-volume hospitals and five of six high-volume hospitals were designated as a COE.
The authors reported that “Overall, 7.3% of patients experienced perioperative complications, most of which were wound problems and other minor complications. Serious complications were most common after gastric bypass (3.6%; 95% confidence interval [CI], 3.2%-4.0%), followed by sleeve gastrectomy (2.2%; 95% CI, 1.2% - 3.2%), and laparoscopic adjustable gastric band (0.9%; 95% CI, 0.6% - 1.1%) procedures (P< .001). Mortality occurred in 0.04% (95% CI, 0.001%-0.13%) of laparoscopic adjustable gastric band, 0 sleeve gastrectomy, and 0.14% (95% CI, 0.08% - 0.25%) of the gastric bypass patients.”
The authors further noted that “Risk of serious complications was inversely associated with average annual bariatric procedure volume (Table 2). For surgeon volume, rates in the low-, medium-, and high-volume categories were 3.8% (95% CI, 3.2% - 4.5%), 2.4% (95% CI, 2.1% - 2.8%), and 1.9% (95% CI, 1.4% - 2.3%), respectively (P for trend = 0.001). For hospital volume, adjusted rates of serious complications were 4.1% (95% CI, 3.0% - 5.1%), 2.7% (95% CI, 2.2%-
3.2%), and 2.3% (95% CI, 2.0% - 2.6%) in low-, medium-, and high-volume hospitals, respectively (P for the trend < 0.001). Serious complication rates were about twice as high (4.0%; 95% CI, 2.8% - 5.3%) for low-volume surgeons at low-volume hospitals than for high-volume surgeons at high-volume hospitals (1.9%; 95% CI, 1.4% - 2.3%).”
For the COE vs non-COE comparison, the authors found that “Overall, rates of serious complications were similar among patients undergoing surgery at a COE (2.7%; 95% CI, 2.5% - 3.1%) than for patients undergoing surgery at non-COE hospitals (2.0%; 95% CI, 1.5% - 2.4%). After adjustment for patient case and procedure mix, there remained no significant difference in rates of serious complications at COE and non-COE hospitals (adjust odds ratio (OR), 1.27; 95%
CI, 0.72 – 2.25); P = 0.41). There also was no significant difference (adjusted OR, 1.34; 95% CI, 0.88 – 2.05; P = 0.18) in rates of serious complications in the COE hospitals compared with the non-COE hospitals within hospital procedure volume categories.”
In their discussion, the authors stated that “procedure volume has been shown to be an important predictor of adverse outcomes in bariatric surgery.” They also noted a number of limitations to their study including the fact that “because all but 8 of the 25 hospitals were COE-accredited by the end of the study period, we had suboptimal statistical power for detecting differences in risk between COE and non-COE hospitals.” In addition, the authors acknowledged that their “study finding may not be generalizable outside of the state of Michigan.”
The authors concluded that “the frequency of serious complications among patients undergoing bariatric surgery in Michigan was relatively low. Rates of serious complications are inversely associated with hospital and surgeon procedure volume but not COE status.”
Kohn GP, Galanko JA, Overby DW and Farrell TM. High case volumes and surgical fellowships are associated with improved outcomes for bariatric surgery patients: a justification of current credentialing initiatives for practice and training. J Am Coll Surg 2010;210:909.
The authors conducted a retrospective analysis of data from 1998 to 2006 from the Nationwide Inpatient Sample database, which was comprised of 1,045 hospitals in 38 states (approximately a 20% stratified sample of all non-Federal hospitals). The goal of the analysis was to examine the effects of case volume and COE status on outcome. Based on the use of ICD-9-CM codes, the procedure groups included in the analysis were gastroplasty, gastric bypass, malabsorptive and laparoscopic adjustable gastric band. Prior to the posting of the 2006 NCD, a hospital's COE status was determined by searching the ACS and ASMBS/SRC websites. Since only hospitals currently certified could be found on these websites, the authors "assumed that current designation as such was in place throughout the study period." For that part of the database collected after the posting of the NCD, the authors determined a hospital's COE status by searching the CMS website. ICD-9-CM codes were used to determine the presence or absence of perioperative complications. For the purposes of the analysis, the occurrence of death or at least one of 15 distinct diagnosis codes resulted in a classification of "any complication." In-hospital mortality was the other outcome studied. Long term outcomes were not studied. Logistic regression modeling was performed. In this model, case volume was used as a continuous variable rather than as a binary variable (e.g., less than 125 cases versus 125 cases or more).
The cohort consisted of 102,069 bariatric procedure cases. Patient characteristics such as age, gender or BMI were not reported. However, the authors determined the Charlson comorbidity index for each inpatient record, which is a way to characterize the degree of comorbidity for the patient (the higher the score, the greater the comorbidity). The mean (SD) Charlson index score steadily increased during this time period; the score was 0.308 (0.574) in 1998 and 0.557 (0.712) in 2006. The number of hospitals with an annual case volume of more than 125 steadily increased from 1 in 1998 to 51 in 2004 but then decreased to 37 in 2005 and 39 in 2006.
With regards to outcomes, in an analysis that controlled for the Charlson score and year, the overall in-hospital mortality rate for all bariatric cases steadily decreased; the rate was 0.61% in 1998 and 0.13% in 2006. For perioperative complications, the authors noted that for all bariatric cases "Nearly all analyzed complication categories showed an inverse correlation with case volume, with any complication, death, requirement for postoperative abdominal drainage, acute pulmonary embolism, cardiac complications, splenectomy, acute renal failure, bacterial pneumonia, and acute respiratory failure rates achieving statistically significant improvement." No inverse correlation with increasing case volume was seen for acute DVT, myocardial infarction and acute CVA.
In an analysis to determine the association between outcomes and COE designation for all bariatric cases after controlling for year, Charlson score and case volume, there was no statistically significant association between complications and the presence of a COE designation by ACS or by ASMBS except for respiratory failure (where a decrease in the rate of respiratory failure was associated with both the ACS-based and the ASMBS-based COE designations) and for acute DVT (where a decrease in the rate of acute DVT was associated with the ACS-based COE designation).
Kohn et al. identified some limitations with their analysis. They sourced their data from an administrative database, which is dependent on the use of medical codes that can be clinically-nonspecific or ambiguous and revised periodically over time. These characteristics can lead to undetected, and therefore unaccounted for, changes in the data that were included in the analysis. In addition, the database comprised only a small (20%) sample of the possible hospitals and U.S. states in the U.S.
The authors concluded that "the hypothesized positive volume-outcomes relationship of bariatric surgery has been shown with analysis of case volume as a continuous variable and without arbitrarily categorizing hospitals to case volume groups. The concept of volume-independent COE designation has been supported, although there is minimal association between outcomes and the credentialing process itself."
Flum DR, Kwon S, MacLeod K, Wang B, Alfonso-Cristancho R, Garrison LP and Sullivan SD. The use, safety and cost of bariatric surgery before and after Medicare's national coverage decision. Ann Surg 2011;254:860-865.
Flum et al. conducted a retrospective analysis of Medicare Part A and Part B data from January 1, 2004 through December 31, 2008 (i.e., a comparison of outcomes before and after implementation of the 2006 NCD) obtained via the Research Data Assistance Center as well as enrollment data from the Social Security Administration and the Railroad Retirement Board. The authors stated that “Temporal trends in bariatric procedures and mortality were evaluated by quarter. Procedures/100,000 CMS enrollees, numbers of unique surgeons and sites performing bariatric procedures were calculated.” Outcomes evaluated were 90-day mortality and readmission within 90 days of surgery. Long term outcomes were not evaluated. Logistic regression modeling was used to compare outcomes pre- and post-NCD implementation.
In reporting the results of the study, the authors noted that a “total of 47,030 CMS patients underwent bariatric procedures between January 1, 2004 to December 31, 2008. The rates of bariatric procedures increased from 15.0 procedures/100,000 CMS enrollees in 2004 to 21.9/100,000 in 2005, then decreased to 17.8/100,000 in 2006 and increased thereafter to 23.8/100,000 and 29.1/100,000 in 2007 and 2008, respectively. There was a significant increase in the mean age of those undergoing procedures from pre-NCD to post-NCD (51.0 +/- 11.1 years vs 54.0 +/- 11.7 years, p < 0.001), whereas the nonage entitlement beneficiary group (ie, medically disabled or renal failure and under age 65) decreased from 85.7% to 73.8% in the post-NCD era (p < 0.001). Women comprised 76.8% of the patients before pre-NCD and 74.7% of the patients post-NCD. Information regarding the BMI was not reported. The mean comorbidity index of bariatric cases increased slightly post-NCD (0.91 to 0.96, p < 0.001) and those with comorbidity scores ≥ 3 increased post-NCD (5.9% vs 7.4%, p < 0.001). The most common procedures in the entire study period were laparoscopic roux-en-y gastric bypass (LRYGB, 43.9%), open roux-en-y gastric bypass (ORYGB. 28.5%), and LAGB (3.8%). There was a significant change in the type of gastric bypass surgery performed from ORYGB to LRYGB between the pre-NCD era (61.2% open and 38.8% laparoscopic) and post-NCD era (20.8% open and 79.2% laparoscopic). There was a substantial increase in the LAGB procedures in the post-NCD (0% pre-NCD and 36.7% of all operations post-NCD). The numbers of sites and surgeons performing surgery decreased (absolute reductions of 48.6% and 47.8%, respectively) after the NCD and did not recover to reach pre-NCD levels."
The authors noted that "Outcomes improved after the NCD (Table 2). The 90-day mortality rate pre-NCD was 1.5% (1.8% ORYGB, 1.1% LRYGB) and post-NCD was 0.7% (1.7% ORYGB, 0.8% LRYGB, 0.3% LAGB) (p < 0.001). After controlling for time trends (Fig. 3), the estimated pre-NCD 90-day mortality rate was 1.7% falling to 1.3% after the NCD (reduction in relative risk of 22.9%, p = 0.05)." More analysis of the 90-day mortality rate showed that the "unadjusted impact of the NCD on the rate of 90-day deaths was a reduction of 0.65% (p < 0.01). After controlling for covariates (age, sex, body mass index, and comorbidity index) and time trends this effect persisted, but the magnitude of the impact was lower - 0.36% (p = 0.03). After controlling for the change in procedure type, the observed reduction in mortality rate was no longer significant - 0.21% (p = 0.18)."
The authors stated that in their study "adjusted analyses that accounted for temporal trends, sex, age, changes in procedure types and comorbidity index, found that reductions in 90-day mortality were largely accounted for by a shift to lower risk procedures and a change in patient characteristics (an increased proportion were Medicare-eligible related to age ≥ 65 years with fewer patients who were Medicare-eligible related to disability [age < 65]) and not necessarily the results of a shift to accredited centers." In conclusion, the authors noted that "the CMS bariatric surgery NCD was associated with a temporary reduction in case volume, a near halving of the 90-day mortality rate" and "significant decreases in serious complications and readmissions." In addition, the impact of the NCD on safety "in the CMS population seems to be accounted for mostly by shifts in procedure types and patient characteristics rather than in shifts of patients to accredited centers alone."
Kwon S, Wang B, Wong E, Alfonso-Cristancho R, Sullivan SD and Flum DR. The impact of accreditation on safety and cost of bariatric surgery. Surg Obes Relat Dis 2012; ePub available online December 3, 2012.
Kwon et al. performed a retrospective analysis of the MarketScan Commercial Claims and Encounter Database, which contains “claims for inpatient care for about 29.1 million patients < 65 years of age who have employer-sponsored insurance plans across broad geographic coverage.” The time frame was 2003 to 2009. Patients were included in this analysis if they were morbidly obese and did not have Medicare Supplemental insurance. The Medicare Supplemental database was used to identify centers performing bariatric surgery in the Medicare population after posting of the 2006 NCD; these centers were designated as COEs for the analysis. Centers that performed bariatric surgery on Medicare patients before but not after the NCD were designated as non-COEs for the analysis. The outcomes for the analysis were inpatient mortality and surgical complications. The goal of this analysis was to “assess the impact of COE accreditation on commercially insured patients distinct from other factors using a difference in difference approach between those having surgery at hospitals that did and did not become COEs before and after the NCD.” Kwon et al. chose the goal and methods for this analysis due to the results and limitations found in a prior analysis (Flum 2011). The authors noted that, in Flum, 2011, “our group evaluated fee-for-service CMS beneficiaries before and after the NCD and found that outcomes improved and costs were reduced but that this impact was most significantly influenced by a shift to safer procedures and to patients with lower risk clinical characteristics rather than through an independent effect of shifts to accredited centers. We found that distinguishing the effect of centers from shifts in patients and procedures and other temporal trends can be challenging. Because after the NCD, CMS beneficiaries could only receive treatment at COEs, teasing out the effect of center accreditation using Medicare data was even more challenging. Patients with commercial insurance are not necessarily limited to undergo bariatric surgery in COEs after the NCD. We hypothesized that commercially insured patients having surgery at non-COEs (after the NCD) might be an appropriate control to evaluate the effect of accreditation status on outcome compared with outcomes among patients with commercial insurance having surgery at COEs.”
A total of 30,755 patients were included in the analysis; 14,989 had surgery during the 37 months prior to the NCD and 15,766 had surgery in the 43 months after the NCD. The overall mean (± SD) age was 43.9 (± 10.8) before the NCD and 43.9 (± 11.2) after the NCD. Females comprised 81.3% of the patients before the NCD and 78.5% after the NCD. The mean Charlson co-morbidity score was similar between the pre-NCD and post-NCD groups.
The authors noted that “A total of 7896 patients underwent procedures at sites that became COEs after the NCD. Patients undergoing procedures in COEs in the post-NCD era were more likely to be males but were similar in terms of age and extent of co-morbid conditions compared with pre-NCD era (Table 1). In the COEs, there were significant shifts to more LRYGB and LAGB and less ORYGB. A total of 12,859 patients had surgery in non-COEs before and after the NCD. Patients at non-COE hospitals in the post-NCD era were similar in age but were more likely to be males and had a higher proportion of patients, with at least 1 co-morbidity compared with the pre-NCD era (Table 1). Significant shifts in procedures to more LRYGB and LAGB and away from ORYGB were also seen in the non-COEs.”
With regards to outcomes, the authors reported an inpatient mortality rate of 0.3% before the NCD and 0.2% after the NCD (p = 0.1). In the COEs, the unadjusted in-hospital mortality rate was 0.3% before the NCD and 0.1% after the NCD (p = 0.01); in the non-COEs, the unadjusted in-hospital mortality rate was the same before and after the NCD (0.2%). For COEs, there was a statistically significant decrease in 90-day complications after the NCD compared to before the NCD (27.6% vs 36.4%, respectively; p < 0.05). The non-COEs also had a statistically significant decrease in the 90-day complication rate after the NCD compared to before the NCD (29.7% vs 36.3%, respectively; p < 0.001).
To analyze the impact of accreditation on outcomes, Kwon et al. used a difference-in-difference model to account for temporal trends, varying patient risk and changes in procedural preferences over time. The authors reported that “After controlling for covariates (age, gender, and co-morbidity index), time trends (by adjusting for changes in outcomes pre- and post-NCD occurring in the non-COEs), and procedure types, there was a .04% decrease in the inpatient mortality rate (P = .1) at the COEs due to the NCD (Table 3).” However, a significant decrease in 90-day complication rates was found (- 2.7%; p = 0.01) at the COEs due to the NCD.
The authors commented that the results of their analysis “suggest that the NCD produced a predominant shift of bariatric operations to COEs and a shift to safe procedures (LRYGB and LAGB) in the post-NCD period. Our DD regression model found that accreditation itself had a significant impact on 90-day complication and reoperation rates and not on inpatient mortality, readmissions, or payments.” Kwon et al. also noted the controversial issue of a volume-outcome relationship in bariatric surgery, which prompted the authors to state that “There may be other mechanisms by which the NCD may have exerted a center effect other than through shifts to higher volume hospitals. COE status through either accrediting body calls for multidisciplinary care team, education activities for patients, care pathways, mandatory reporting of outcomes and best practice infrastructure and personnel requirements. When evaluating COE effects on outcome, any of these factors may play a role, and distinguishing them is difficult if not impossible.”
Kwon et al. noted a number of limitations with their analysis, including the use of data from an administrative database that did not contain clinical information that can provide important predictors of adverse outcomes such as BMI and a patient's functional status. The authors noted a second limitation in that the database "did not include hospital information such as their actual accreditation status at the time of the operation. Rather, we relied on a labeling strategy for the COE looking for those centers performing bariatric surgery on Medicare patients. Those centers that continued to perform surgery on CMS beneficiaries after the NCD were labeled COEs given that the risk of not being reimbursed likely compelled centers to perform surgery on CMS beneficiaries only if they were accredited. Patients may have been misclassified into the group undergoing operations at non-COEs when having their operations in the months before a center became a COE and some patients would have been misclassified as having their operation at a non-COE hospital if the hospital was a COE but performed no operations on CMS beneficiaries after the NCD. A third limitation concerned the difference-in-difference (DD) statistical methodology used to analyze the impact of accreditation on outcomes. The authors stated that "Analytically, although DD has been used to distinguish the effect of policy decision from other changing factors distinct from the NCD, an untestable assumption was made that a change in outcome in the COEs during our study period would have been the same as the change in the non-COEs had the NCD not occurred. Other insurers developed or adopted accreditation programs akin to the NCD criteria and may have affected non-COEs during this time period."
The authors concluded that “the component of CMS’ NCD on bariatric surgery that related to shifting procedures to accredited centers did exert a positive effect on patient outcomes distinct from other factors. However, studies assessing the NCD’s impact on long-term effects, nonsafety outcomes such as weight loss and co-morbid condition improvements, costs, and quality of care are needed.”
Nguyen NT, Nguyen B, Nguyen VQ, Ziogas A, Hohmann S and Stamos MJ. Outcomes of bariatric surgery performed at accredited vs nonaccredited centers. J Am Coll Surg 2012;215:467.
Nguyen et al. conducted a retrospective analysis of data from the United HealthSystem Consortium database. Discharge data for all patients who underwent non-emergent open or laparoscopic Roux-en-Y gastric bypass, laparoscopic adjustable gastric banding or laparoscopic gastroplasty for morbid obesity between October 1, 2007 and December 31, 2009 were analyzed. COE status was first determined by searching the CMS website and then cross-referenced with the list on the ACS (both level 1 and 2) and the SRC websites. The goal was to compare the perioperative outcomes of bariatric procedures performed at COE versus non-COE centers. The primary outcome was in-hospital mortality; a secondary outcome was overall complications. Long term outcomes were not evaluated. Post-hoc analyses based on the type of bariatric procedure performed, the severity of illness during admission and the need for a prolonged ICU stay postoperatively due to a major complication were conducted. For the various statistical analyses performed, differences were determined using chi-square tests or t-tests, as appropriate.
A total of 35,284 patients who met the study criteria underwent bariatric surgery for the treatment of morbid obesity; of these patients, 31,479 had surgery at 71 COEs and 3,805 had surgery at 143 non-COEs. The authors noted that “The mean number of bariatric operations performed per center during the study period was significantly higher at accredited centers (443 vs 88 cases, respectively, p< 0.05). The proportion of females was higher in the nonaccredited group than in the accredited group (80.2% vs 77.7%, respectively, p < 0.05), but there was no significant difference in proportion of severity class between groups. The distributions of age, race, and procedure types were not statistically different between the 2 types of centers.” In COEs 1,322 (4.2%) patients were 65 years old or older; 97 (2.5%) of patients were 65 years old or older in non-COEs.
The authors reported that “Nonaccredited centers are associated with a 3.5-fold increase in observed in-hospital mortality risk (95% CI 1.5 to 8.0) compared with accredited centers (p = 0.003)"; the "calculated risk-adjusted in-hospital mortality was 0.045% at accredited centers and 0.175% at nonaccredited centers." Regarding overall complications, Nguyen et al. noted that the relative risk for overall complications was 0.96 (95% CI 0.77 to 1.20) (not statistically significantly different).
In a post-hoc analysis examining outcomes based on COE status and procedure type, observed in-hospital mortality and overall complications were comparable between COEs and non-COEs for gastric banding. However, 4.9% of patients in a COE had an ICU stay for a major complication vs 1.7% of patients in a non-COE; the relative risk was 0.35 (95% CI 0.21 to 0.57; p < 0.001). In a post-hoc analysis for gastric bypass surgery, overall complications were comparable between COEs and non-COEs but the observed in-hospital mortality rate was 0.06% for patients in a COE and 0.25% for patients in a non-COE; the relative risk was 4.25 (95% CI 1.72 to 10.51; p < 0.002).
The authors commented that "In-hospital mortality was rare for both accredited and non-accredited centers. However, accredited centers were associated with nearly a 4-fold reduction in the risk for in-hospital mortality as compared with nonaccredited centers. Due to the inherent higher procedural volume at accredited centers, we were unable to determine if the improved outcomes were related to accreditation status, procedural volume, or a combination of both. Because accreditation is defined partly by procedural volume, it is statistically impossible to tease out the contributions from each source individually." In addition, the authors stated that "although complication rate and the rate of ICU use were similar between accredited and nonaccredited centers, there was a difference in mortality within a subset of patients requiring prolonged ICU care or hospital stay. These groups of patients were selected as an indicator for the presence of and severity of complications, and we found significantly higher observed in-hospital mortality within nonaccredited centers. The presence of a similar rate of complications but higher mortality rate within nonaccredited centers may indicate a phenomenon that has been previously described as a failure to rescue. This concept proposed that hospitals with higher mortality but lower rates of complications may potentially fail to recognize and/or fail to rescue complications, leading to higher mortality."
Regarding the concept of requiring accreditation, Nguyen et al. noted that "If accreditation truly affects outcomes, it is important to understand the hurdles for bariatric centers in obtaining accreditation. The first and most important hurdle is the volume criteria of 125 cases. It is difficult for many centers to achieve this volume, particularly rural hospitals. A current option for low volume hospitals is to participate in the ACS level 2 centers, representing lower volume hospitals that perform bariatric surgery for lower risk patients, based on age, body mass index, sex, the presence of organ failure, ambulatory status, and lower risk procedure (nonrevisional surgery). Alternatively, with the low mortality data in contemporary bariatric surgery, the centers of excellence construct should be reexamined to put less emphasis on volume and more emphasis on development of a systematic approach for quality improvement similar to the program established by the Michigan Bariatric Surgery Collaborative."
Nguyen et al. noted a number of limitations of their analysis. The authors stated that "Due to the inherent higher volume of bariatric surgery performed at accredited centers, it is difficult to determine if the outcome differences between accredited and nonaccredited centers are related to volume or accreditation status." The lack of follow-up data for outcomes was another limitation. The authors noted that "Complications or deaths arising after discharge would not be captured in this database. We also recognize that some of the limitations of administrative data include accuracy in coding of complications." Finally, "Our study was limited to academic centers; however, the majority of centers of excellence are nonacademic centers so our results may not be representative of these centers."
The authors concluded that “almost 90% of bariatric operations are now performed within accredited centers. Within the context of academic centers, accreditation status was associated with a small but significant improvement of in-hospital mortality and perioperative outcomes. Post-hoc analyses performed were exploratory and hypothesis-generating to find reason for improved mortality within accredited centers. These analyses suggested associations between accreditation status and improved in-hospital mortality for patients who underwent the gastric bypass operation and for patients with higher severity of illness. The improved mortality rate associated with accredited centers may be
attributed to the centers' ability to recognize and rescue complications."
Dimick JB, Nicholas LH, Ryan AM, Thumma JR and Birkmeyer JD. Bariatric surgery complications before vs after implementation of a national policy restricting coverage to centers of excellence. JAMA 2013;309:792.
Dimick et al. performed an analysis of data from the State Inpatient Databases, which are maintained by AHRQ and include "all inpatient discharges from short-term, acute-care, nonfederal, general, and other specialty hospitals in participating states." The data included in the analysis were from 2004 to 2009 and from 12 states (Arizona, California, Florida, Iowa, Massachusetts, Maryland, North Carolina, Nebraska, New Jersey, New York, Washington and Wisconsin). To be included in the analysis "patients had to have a procedure code for bariatric surgery with a confirmatory primary or secondary diagnosis code for morbid obesity and a DRG code for weight loss surgery (DRG code 288 through October 1, 2007 and MS-DRG 619 - 621 after October 1, 2007)." Patients with a diagnostic code for abdominal cancer were excluded. The authors' goal was "to examine outcomes in Medicare patients before compared with after the implementation of the CMS policy that restricted coverage of bariatric surgery to hospitals designated as COEs."
The outcomes of interest were complications, serious complications and reoperations. A serious complication was defined as "the presence of a coded complication and an extended length of stay (≥ 5 days)." Long term outcomes were not evaluated.
Logistic regression was used to perform a difference-in-difference analysis, which is an econometric technique that is "commonly used to evaluate the impact of policy changes. This approach isolates changes in outcomes associated with the policy change above and beyond any secular changes observed in a control group not exposed to the policy change." The control group was comprised of non-Medicare patients undergoing bariatric surgery. Various adjustments were performed during these analyses to adjust for patient characteristics, secular trends and procedure type (ORYGB; LRYGB; LAGB; other). Sensitivity analyses were conducted.
A distinct analysis was conducted to assess the effect of COE status on outcomes. The COE list on the CMS website was used to identify hospitals with a COE designation. The authors "conducted a patient-level analysis comparing each of the adverse outcomes in hospitals designated as COEs vs non-COEs at the time the patient underwent surgery. In these analyses, we adjusted for patient characteristics, procedure type, and the time period (quarter and year of surgery). Given the strong secular trend towards improved outcomes, and the increasing number of COEs over time, accounting for the period in which the patient had surgery proved to be important. Because Medicare patients no longer underwent bariatric surgery in non-COEs after the coverage decision, we performed our main analysis combining Medicare and non-Medicare patients together. However, we performed a sensitivity analysis comparing outcomes at COEs with non-COEs for Medicare and non-Medicare patients separately, which demonstrated similar findings. Given the possibility of unmeasured differences in patient characteristics between those treated at COEs and non-COEs, we conducted a sensitivity analysis comparing these 2 groups using an instrumental variable approach. In this analysis, we used the national coverage decision as an instrument to pseudorandomize patients to COEs and non-COEs. The results of this analysis also demonstrated no difference between COEs and non-COEs, enabling us to report our results using standard logistic regression."
A total of 102,281 patients received a bariatric surgery procedure prior to implementation of the 2006 NCD while 170,961 patients received a bariatric surgery procedure after implementation of the 2006 NCD. Patient characteristics are presented in the following table:
|| Medicare patients
|Before 2006 NCD
|| After 2006 NCD
||Before 2006 NCD
|| After 2006 NCD
Age (mean ± SD)
Procedure type, %
* p < 0.001
The increase in the use of LAGB was significantly larger for the Medicare group compared to the increase in the non-Medicare group (p < 0.001). The authors also noted that Medicare patients "had more comorbid conditions" however they did not indicate if any differences between groups were statistically significant. Information regarding the BMI was not reported.
Dimick et al. reported that "rates of any complication, serious complications, and reoperation decreased substantially after the CMS coverage decision in both Medicare and non-Medicare patients" however "trends towards improved outcomes were well underway before the implementation of the CMS restriction of care to COEs. A large proportion of the improved outcomes over time for both Medicare and non-Medicare patients could be attributed to the changes in procedure mix. After adjusting for the type of bariatric procedure performed, the RR for adverse outcomes after (vs before) the CMS policy was much lower (Table 2). In contrast, none of the improvement could be attributed to the CMS policy. After accounting for patient factors, changes in procedure type, and pre-existing trends toward improved outcomes, there were no measureable improvements in outcomes after (vs before) implementation of the CMS national coverage decision for any complication (8.0% after vs 7.0% before; RR, 1.14,[ 95% CI, 0.95 to 1.33]), serious complications (3.3% vs 3.6%, respectively; RR, 0.92 [95% CI, 0.62 to 1.22]), and reoperation (1.0% vs 1.1%; RR 0.90 [95%, 0.64 to 1.17] (Table 2). In a sensitivity analysis limited to only gastric bypass procedures, we found similar findings for all adverse outcomes (Table 2)."
Upon directly comparing outcomes at COEs versus non-COE, the authors "found that COEs (as defined by the CMS coverage decision) did not have better outcomes than non-COEs. After accounting for patient factors, procedure type, and the year of operation, patients undergoing bariatric surgery at hospitals with the COE designation (vs hospitals without the COE designation) did not have significantly different rates for any complication (5.5% vs 6.0%, respectively; RR, 0.98 [95% CI, 0.90 to 1.06]), serious complications (2.2% vs 2.5%; RR, 0.92 [95% CI, 0.84 to 1.00]), and reoperation (0.83% vs 0.96%; RR, 1.00 [95% CI, 0.86 to 1.17]). In a sensitivity analysis that evaluated Medicare and non-Medicare patients separately, we also found no relationship between hospital COE designation and adverse outcomes."
Dimick et al. noted that their analysis "was limited to perioperative safety. We were not able to examine the association of the CMS coverage decision with longer-term outcomes, including patient satisfaction, weight loss, and comorbidity resolution. The authors concluded by noting that they "found no association between the implementation of the COE component of the CMS national coverage decision and improved bariatric surgery outcomes. Consistent with prior studies, we also found no association between COE designation and better bariatric surgery outcomes. However, there are concerns about the effect of the policy on patient access. For example, in a study of patients undergoing bariatric surgery in Texas, Livingston and Burchell found a markedly increased travel distance in Medicare patients after implementation of the CMS coverage decision. Therefore, the CMS policy restricting coverage to COEs has not been associated with improved outcomes for bariatric surgery, but may have had the unintended consequence of reducing access to care. These findings suggest that the CMS should reevaluate this policy."
Jafari MD, Jafari F, Young MT, Smith BR, Phalen MJ and Nguyen NT. Volume and outcome relationship in bariatric surgery in the laparoscopic era. Surg Endosc 2013; ePub available online August 13, 2013.
(This article is referenced as Nguyen 2013 by commenters.)
Jafari et al. conducted a retrospective analysis of data from January 1, 2006 to December 31, 2010 from the Nationwide Inpatient Sample database, which was comprised of 1,000 hospitals across the U.S. (the dataset approximates a 20% stratified sample of all non-Federal hospitals). The goal of the analysis was to examine the effects of case volume and COE status on outcome for elective laparoscopic-only, stapling-only bariatric procedures. The specific procedures included in the analysis were Roux-en-Y gastric bypass and sleeve gastrectomy. A center performing less than 50 cases per year was designated as a low volume center (LVC) and a center preforming ≥ 50 cases per year was designated as a high volume center (HVC). A hospital's COE status was determined by searching the CMS website. The primary outcomes studies were in-hospital mortality and serious morbidity. Long term outcomes were not studied. Logistic regression was performed for the primary analysis (HVC v. LVC) as well as for the subgroup analysis (COE for HVC v. non-COE for HVC) using binary endpoints and risk adjustment based on demographics, hospital characteristics, comorbidities and procedural type.
Volume v. outcome results
A total of 277,760 cases were performed from 2006 through 2010. Eighty-five percent (236,219) of the cases were performed in a HVC (mean ± SEM, 328 ± 48 centers per year; each center performed 144 ± 117 cases per year). Fifteen percent (41,547) of the cases were performed in a LVC (mean ± SEM, 484 ± 50 centers per year; each center performed 17 ± 14 cases per year). Ninety percent of the HVC group and 55% of the LVC group were COE. Gastric bypass was performed the majority of the time (HVC 97.4%; LVC – 94.7%; this difference was statistically significant, p < 0.05). The mean age was similar between the two groups (HVC 43 ± 13; LVC 44 ± 14) as was the proportion of females but the authors reported a higher percentage of Caucasian, Hispanic and Asian/Pacific Islander patients in the LVC group. A statistically significantly greater proportion of rural hospitals were a LVC compared to a HVC (p < 0.05). BMI was not reported. The overall Elixhauser-Van Walraven comorbidity score was similar between the HVC and LVC groups but a statistically significantly higher proportion of specific comorbidities were seen in the HVC group including congestive heart failure, chronic pulmonary disease, diabetes, hypertension, hypothyroidism and renal failure (p < 0.05).
In-hospital mortality was 0.07% in HVCs compared to 0.17% in LVCs (univariate analysis; p < 0.05). Compared to HVCs, LVCs was associated with an odds ratio of 2.5 (p < 0.01) for in-hospital mortality and an odds ratio of 1.2 (P < 0.01) for serious morbidity (multivariate analysis).
COE v. non-COE results in HVCs
Ninety percent of HVCs (mean ± SEM, 296 ± 49 centers per year) were COE; each center performed a 149 ± 122 cases per year. Ten percent of HVCs (mean ± SEM, 40 ± 15 centers per year) were non-COE; each center performed 106 ± 61 cases per year. Gastric bypass was performed the majority of the time (COE – 98.1%; non-COE – 89.3%; this difference was statistically significant, p < 0.05). The mean age was similar between groups (COE – 44 ± 9; non-COE – 44 ±11) but there were statistically significantly more male, African-American and Hispanic patients in the non-COE group (p < 0.05). The vast majority of COE and non-COE centers were in urban locations; a statistically significantly greater proportion of rural hospitals were non-COE compared to COE (p < 0.05). BMI was not reported. The overall Elixhauser-Van Walraven comorbidity score was similar between the COE and non-COE groups but a statistically significantly higher proportion of specific comorbidities were seen in the COE group including congestive heart failure, chronic pulmonary disease, diabetes, hypertension, hypothyroidism, peripheral vascular disease and smoking history.
In-hospital mortality was 0.06% in COEs compared to 0.22% in non-COEs (univariate analysis; p < 0.01). Compared to COEs, non-COEs were associated with an odds ratio of 3.57 (p < 0.01) for in-hospital mortality and an odds ratio of 0.84 (P < 0.01) for serious morbidity (multivariate analysis).
Jafari et al. noted a number of limitations of their analysis associated with the use of the National Inpatient Sample database including the lack of long-term outcomes and clinical information such as BMI (used to perform risk adjustment during statistical analysis and noted by the authors to be “an important preoperative factor that can have an impact outcome”).
The authors concluded that they “found that centers with an annual hospital volume of 50 stapling cases per year had lower risk-adjusted morbidity and mortality rates than centers that managed fewer than 50 stapling cases per year. Relative to HVCs with accreditation, non-accredited centers were associated with higher risk-adjusted mortality rates. Even high-volume non-accredited centers that managed more than 50 cases per year had in-hospital mortality rates similar to those of LVCs. Our data therefore suggest that accreditation may have a greater impact on outcome than volume.”
The MEDCAC was not convened for this review.
5. Evidence-based guidelines
No guidelines that referenced evidence were found.
6. Professional Society Position Statements
The ASMBS and the ACS are in the process of creating a single, unified program to be called the ASMBS/ACS Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP). The societies state that the goal is to “finalize the revised standards and begin implementation by year’s end.” More details can be found at http://asmbs.org/2013/03/asmbs-quality-updates-mbsaqip-cms-and-more/
(accessed March 28, 2013).
7. Public Comments
Initial 30 day comment period - (01/24/2013 -02/23/2013)
CMS received 214 comments during the initial public comment period. A summary of these comments can be found in the proposed decision memorandum and the complete text of these comments is available on the CMS website at View Public Comments (http://www.cms.gov/medicare-coverage-database/details/nca-view-public-comments.aspx?NCAId=266&ExpandComments=n&NcaName=Bariatric+Surgery+for+the+Treatment+of+Morbid+Obesity+-+Facility+Certification+Requirement+(3rd+Recon)&bc=ACAAAAAACAAAAA%3d%3d&).
Public Comments on the Proposed Decision Memorandum
CMS received 483 comments on the proposed decision. Of the 483 comments, 92 advocated eliminating the facility certification requirement and 387 advocated keeping the facility certification requirement. The content of at least thirty percent of the comments that advocated keeping the facility certification requirement was an exact duplicate of content provided on the ASMBS website solicitation for comments. While CMS values input through our comment process, multiple comment submissions by form letters or duplicated content do not further inform the scientific evidence for our decision beyond the content of the first comment received. Of the four remaining commenters, one did not advocate a position, one commenter was ambiguous as to the desired result, and two commenters addressed specific bariatric surgery procedures.
There were six comments from national societies. Of these six comments, one was signed by five national societies and two comments were identical from the same society. Five of these comments advocated keeping the facility certification and one advocated eliminating the facility certification requirement.
A number of commenters provided references. All references were reviewed for relevance to the scope of the NCA and a list of these references is provided in Appendix B. The references that were determined to be relevant to the scope of this NCA are incorporated into the review and included in the bibliography.
The following issues were raised by the commenters.
Access to Care
Comment: Many commenters cited concerns about the barriers to access to care that they alleged resulted from the facility certification requirement. Many gave anecdotal commentary about the local availability of capable bariatric surgeons with good outcomes. They noted the long distance travel for patients who often don’t have the resources to travel to certified facilities and also opposed having to refer Medicare patients to competitor hospitals. Many claimed that the requirement has limited access to needed treatment for large numbers of people, particularly in rural settings. A commenter claimed that this requirement discriminated against patients in rural communities. Another commenter stated that it also presented a barrier to access to care in urban areas serving the low-income Medicaid population. A number of commenters stated that Medicare patients should have the right to choose where they have their bariatric procedure.
A researcher asserted that the facility certification policy has adversely impacted access to surgery among minority patients and distorted choice of procedure types. This commenter asserted that the multiple pre and post-operative visits required and the loss of access to their preferred hospitals may have deterred minority patients from pursuing bariatric surgery.
Some commenters stated there was no evidence of barriers to access to care. Some concluded that since the volume of bariatric surgery procedures increased in the years after the facility certification requirement, this proved there were no barriers to access to care. Some of the societies asserted that since there are more than 700 accredited bariatric surgery centers nationwide there is no added undue burden on the patient. The societies also asserted that with the new lowered volume standard there would be more accredited centers.
Response: Comments asserting limitations to access to care are very concerning for CMS. We recognize (see Appendix A) that reports of anecdotal experiences have limited evidentiary persuasiveness, regardless of whether they support or oppose our proposed decision. That said, we believe that appropriate balances can be achieved when considering coverage requirements. In this case, we have concluded that the technological progress of bariatric surgery and the dissemination of surgical expertise adequately support our removal of the facility certification requirement.
Quality and Outcomes
Comment: Many commenters believed that the mortality and complication rates related to bariatric surgery have decreased because of the certification program. Concerns were expressed that quality improvement efforts will be hampered if Medicare coverage does not include the certification requirement in the NCD. A number of commenters expressed concerns that without the facility certification requirement bariatric surgery would revert back to the higher complication and mortality rates that existed before the requirement.
A number of commenters also asserted that their bariatric surgery programs produced outcomes that were equal to or better than those reported in the literature but were unable to become a certified facility because of the volume requirement. Some commenters asserted that the ASMBS and ACS programs have pushed hospitals to develop the infrastructure that resulted in the improvements in the quality of bariatric surgery. They stated that the claims by some surgeons of quality and outcomes equal to or better than the COE were because they had adopted the same requirements of the COE. One of the societies believed that the COE requirement has improved bariatric surgery outcomes in the U.S., both at COE and non-COE centers, because the non-COE centers strive to satisfy the COE requirements and model their programs accordingly.
Response: CMS agrees that there is evidence of improved mortality and morbidity for both Medicare and non-Medicare bariatric surgery patients since 2006. However, based on the evidence reviewed we do not believe the evidence shows a causal relationship of the NCD requirement for facility certification and these improvements. The impact of advancements in bariatric surgery, including the maturation of the field to less invasive bariatric surgery procedures during this time period, should not be discounted.
Commitment to Multi-disciplinary Team Approach and Structure
Comment: Commenters wrote about the need for the proper equipment, training and personnel. Commenters stated that the ancillary services and multi-disciplinary team approach provided to the bariatric surgery patients were important to the successful outcomes. This approach included in-depth dietary and nutritional counseling, exercise counseling, behavior modification and psychological support. Commenters expressed the opinion that after care programs are just as critical as the surgery itself. Commenters believed these services are important to support the patient. These commenters expressed concerns that without the certification requirement the resources to support the team approach to care would no longer be provided by the institutions. They believed that facilities would no longer invest in the necessary infrastructure. Some commenters expressed concerns about loss of jobs and lack of services for patients.
Response: The removal of a coverage requirement does not require facilities to discontinue practices which they find beneficial. Facilities may indeed find other reasons to continue certification, e.g. to distinguish themselves from uncertified competitors. While CMS agrees with the value of the multidisciplinary team approach and structure, we do not believe that every valued endeavor needs to be buttressed by a Medicare mandate. We expect all facilities to strive to provide the proper equipment and services to meet the needs of its patient population.
Consistency of CMS Policy
Comment: Some commenters believed that elimination of the bariatric surgery facility certification requirement is a radical departure from CMS policy and previous bariatric surgery initiatives. They identified a number of CMS NCDs that have facility requirements or certification requirements. It was also stated that CMS would be the only major payer not to have facility certification for bariatric surgery.
Response: CMS policy is based on the persuasiveness of available evidence and we expect that policy can and should evolve when new evidence supports a change. That concept, rather than any point in time specific coverage requirement, embodies a consistent approach to policy. CMS does from time to time include requirements for facility and/or physician standards, or certain certification requirements in our NCDs; however, we exercise this option after considered counsel and we are cognizant of the responsibility such requirements establish. Each issue is considered individually by CMS in our review of the evidence. Bariatric surgery is no longer new and is substantially more disseminated throughout the medical community since the 2006 NCD. Ultimately, it is the convincing nature the evidence surrounding the item or service under review that guides CMS decisions concerning whether or not certification requirements are needed for an item or service to be reasonable and necessary. Over time these factors that informed our original decisions may change, supporting a re-evaluation of a coverage requirement.
CMS believes, based on evidence, that the conditions under which bariatric surgery is furnished have meaningfully changed since the 2006 decision. Therefore, in the current context of care, CMS concludes that continuation of a facility certification requirement should not be required as a condition of coverage.
While CMS believes that continued efforts at improving outcomes are important (especially documenting long-term outcomes), we also believe that it is the responsibility of the bariatric surgery community to pursue this goal. Thoracic surgery provides an example of soliciting cooperation from their providers to develop a structure for continuous quality improvement without a mandate from the Medicare program.
CMS does not discount the possible value of an accreditation program focused on quality improvement and outcomes. The ASMBS and the ACS have had the benefit of seven years of mandated participation for Medicare to establish the value of their accreditation programs within the medical community. We hope they continue forward with an outcomes focused program showing the best approaches for short term and long term success for bariatric surgery.
Medicare Population and Risk
Comment: A number of commenters identified the Medicare population as a vulnerable and at-risk population and claimed that the elimination of facility certification would result in increased mortality and morbidity. A commenter expressed that most Medicare patients with obesity have a multitude of other medical conditions necessitating specialized care. Another commenter pointed out that these same patients have other types of procedures such as cardiac surgery or neurosurgery but facility certification is not required. The societies commented on the higher risk for morbidity and mortality for the Medicare population than the general bariatric surgery population and noted some references that described this risk.
Response: Medicare beneficiaries may have co-morbid conditions that often put them at higher risk for bariatric surgery as well as other surgeries. The improvements that have occurred in mortality and morbidity after bariatric surgery have occurred in the Medicare as well as the non-Medicare population. We have no evidence to support the societies’ assertion (referenced in the societies’ comment as Nguyen 2013) that the survival benefit shown in Perry 2008 would be extinguished if surgeries were performed in non-accredited centers. The facility certification program is not solely based on volume, it only represents one element. CMS does not believe the evidence shows a causal relationship of the NCD requirement for facility certification and the improvements in mortality and morbidity.
Comment: A number of commenters used the content provided on the ASMBS website as their comment and included references to identify patient safety issues. The Encinosa 2009, Nguyen 2010, Nguyen 2012, Kwon 2012, Flum 2011 and Dimick 2013 and Nguyen 2013 references were used to claim that the decrease in complication and mortality since the implementation of the 2006 NCD requirement for facility certification is secondary to that NCD.
Response: All of these references were reviewed for the reconsideration of the NCD and included in the bibliography of the proposed decision. The reference of Nguyen 2013(Jafari et al. 2013) has been included in our evidence and analysis section of the final decision memorandum. The Encinosa 2009 study did not perform a COE versus non-COE analysis and so was not part of the evidence review but was considered in developing the decision. As documented in the decision memorandum, the evidence does show that the complication rates and mortality rates for both Medicare and non-Medicare patients undergoing bariatric surgery have declined. We do not believe the evidence shows a direct causal relationship to these improvements. During the same period of time the bariatric surgery procedures moved to a less invasive approach using laparoscopic surgery. The field of bariatric surgery was maturing and hospitals were creating a more informed structure for dealing with these patients.
Communication with Certifying Organizations
Comment: Society commenters claimed a lack of communication between CMS and their organizations as the administrators of the certification programs that are most active in bariatric surgery. The claim was made that both ASMBS and ACS have a tremendous amount of data and experience that could help CMS better understand the value of accreditation.
Response: CMS was unable to identify any published evidence using these data to show the value of the certification requirement. In addition, on March 5, 2013 and August 15, 2013, the ASMBS had a telephone conference with CMS on the topic of certification. No new persuasive evidence was provided during these conference calls. We believe the organizations administering the certification program, which are the most active in bariatric surgery, have had ample opportunity to communicate with CMS or to submit their data and information.
CMS remains committed to transparent communications from interested parties on an issue under review. When CMS opens a new or reconsideration of a NCD we post a tracking sheet to inform the public. The NCD process is designed to be as transparent as possible, so communications on an open topic can be acknowledged in the public forum. For transparency sake, it is preferred that the evidence used in deliberations of an NCD be published and therefore available to the public.
Comment: The societies stated that the facility certification programs of the ASMBS and ACS were not established for nor intended to be research projects to determine efficacy of certification.
Response: When the NCD requirement was established in 2006, CMS believed that the facility certification programs offered by the ASMBS and ACS were necessary for these services to be reasonable and necessary. Both programs included requirements for monitoring and tracking outcomes. CMS is cognizant of the investment of effort when requirements such as the bariatric surgery facility certification are part of a NCD. We have a responsibility to insure that any requirement we impose through the NCD process is balanced convincingly with the advantages provided.
Our decision to remove the requirement for facility certification for bariatric surgery is reflective of the existing evidence and circumstances today. The requirements of an NCD are open to reconsideration when the evidence warrants. The elimination of the requirement for the facility certification for bariatric surgery in no way negates the benefits these programs may have provided in the past, it is only reflective of the evidence and circumstances that exist today. These organizations have had the unique opportunity with a NCD mandate to be able to prove value and convince the bariatric surgery community of the value of voluntarily participating in such programs. We applaud the many efforts of continuous quality improvement in health care that exist today on a voluntary basis and we believe that bariatric surgery has evolved to the point to transition to a voluntary program.
Review of the Evidence
Comment: The comment from the five societies claimed that our proposed decision was based on and incomplete review and analysis of the evidence. They went on to criticize the studies offered against facility accreditation. Specifically, they criticized the Livingston 2009 study because it utilized data predating the 2006 NCD. The criticism of the Birkmeyer 2010 study addressed the requirements to be part of the Michigan Collaborative were virtually the same as the current certification process so there was no difference in the facilities compared. They believed that the MBSC population was not generalizable to the Medicare population.
Further criticisms were made by the societies of the Dimick 2013 study because it used administrative data, did not use mortality as an outcome and made what the societies claim was a flawed assumption that the control group was not exposed to the policy change. The societies asserted that by 2006 the private payers had requirements for hospital accreditation that preceded the CMS NCD. They stated the author’s main objection against accreditation was limiting access which the societies claim is unfounded. The societies commented on the increase in the number of procedures in Medicare beneficiaries from pre-NCD to post-NCD and believed that access actually improved. They also disagreed with the author’s assertion of a minimum volume effect in bariatric surgery.
Response: We disagree. The proposed decision memorandum clearly stated that the focus of the evidentiary review was on studies that performed an analysis of data from COEs versus non-COEs. This focus resulted in the review of eight studies (Livingston 2009; Nguyen 2010; Birkmeyer 2010; Flum 2011; Kohn 2010; Kwon 2012; Nguyen 2012; Dimick 2013). In the proposed decision memorandum CMS specifically noted the substantial limitations of Livingston 2009, Birkmeyer 2010 as well as Kohn 2010. CMS believes the findings from the remaining five studies to be mixed at best, as explained in the analysis section of the proposed decision memorandum.
The societies stated that there were seven studies in support of facility certification (Hollenbeak 2008; Encinosa 2009; Nguyen 2010; Farrell 2010; Nguyen 2012; Flum 2011; Kwon 2012). The Hollenbeak 2008 and Encinosa 2009 studies did not perform a COE v. non-COE analysis and therefore were not included in the evidence section of the proposed decision memorandum. Farrell 2010, cited as Kohn 2010, is included in the evidence section of the proposed decision memorandum, and as noted above was considered to have substantial limitations. The remaining studies are also in the evidence section and CMS’ assessment was presented in the analysis section of the proposed decision
Comment: A number of commenters mentioned a new study by Nguyen et al., which is in Surgical Endoscopy and titled Volumes and Outcome relationship in Bariatric surgery in the Laparoscopic Era (reference: Nguyen 2013). Dr. Nguyen also mentioned this publication in his personal comment but said it was in press. This article is referenced on the ASMBS website soliciting comments to support continuing facility certification and providing content for the comments. The comment from the five societies also mentioned this publication and summarized the findings.
Response: The Nguyen 2013 reference, cited as Jafari et al. 2013, has been included in the evidence and analysis section of the final decision memorandum.
Comment: One commenter believed that support for the certification requirement is motivated by a desire to prevent competition rather than promote good care. This commenter stated that COE programs for bariatric surgery are used as an economic weapon by large academic centers and others against surgeons such as himself. Similar concerns were expressed by other commenters, who stated that the pressure to continue with COEs is from those in pursuit of their own self-interest. There were two comments regarding conflict of interest concerns. The added cost of the certification program was also mentioned in the comments.
Response: The comments make it clear that this is a polarizing issue; some comments are expressed based from the haves versus the have-nots perspective. We recognize that commenters may have personal interests, financial or other, and that such interests might not be explicitly acknowledged by commenters. We do endeavor, to the extent possible, to account for these biases in our attention to the best available evidence.
Comment: One Society advocated eliminating the certification requirement because of a mandate that requires anesthesiologist provision or supervision of anesthesia care in bariatric facilities. This society believed this was a costly mandate without evidence to support it.
Response: CMS appreciates this comment.
Comment: One commenter stated that the code for conducting an adjustment of a gastric band should be included in the NCD as a covered procedure. They did not believe that the decision for this procedure should be made by the Medicare Administrative Contractor.
Response: The NCD does not address the procedure for adjustment of the gastric band. The adjustment of the gastric band procedure remains under the discretion of the Medicare Administrative Contractor to address this matter.
Comment: One commenter stated that sleeve gastrectomy should be adopted by Medicare.
Response: CMS completed a NCA on laparoscopic sleeve gastrectomy in 2012. After reviewing the evidence, it was determined that coverage for this procedure should be made by the Medicare Administrative Contractor.
Open sleeve gastrectomy is non-covered by Medicare and was not part of the evidentiary review in this NCA. The NCD on bariatric surgery procedures can be found in the NCD Manual, section 100.1 (http://www.cms.gov/medicare-coverage-database/details/ncd-details.aspx?NCDId=57&ncdver=4&bc=AAAAgAAAAAAAAA%3d%3d&).
VIII. CMS Analysis
National coverage determinations (NCDs) are determinations by the Secretary with respect to whether or not a particular item or service is covered nationally by Medicare (§1862(l) of the Act).
In order to be covered by Medicare, an item or service must fall within one or more benefit categories contained within Part A or Part B, and must not be otherwise excluded from coverage. Moreover, section 1862(a)(1) of the Social Security Act in part states, with limited exceptions, no payment may be made under part A or part B for any expenses incurred for items or services:
- Which, are not reasonable and necessary for the diagnosis or treatment of illness or injury or to improve the functioning of a malformed body member (§1862(a)(1)(A)).
As noted earlier, our review sought the answer to the question below. We have repeated it here for the convenience of the reader.
Is the evidence sufficient to conclude that facility certification (sometimes referred to as a COE designation) improves meaningful health outcomes for Medicare beneficiaries who undergo a covered bariatric surgery?
We reviewed nine studies that examined the utility/relevance of a COE designation. In their 2009 article, Livingston et al. conducted an analysis of National Inpatient Survey data from 2005. During the analysis the hospitals in that database were designated as a COE or non-COE after the authors visually matched the survey’s list of hospitals with the current list of COE hospitals on the CMS website. The results revealed an in-hospital mortality rate of 0.17% in COEs and 0.09% in non-COEs as well as a complication rate of 6.3% in COEs and 6.4% in non-COEs; these differences were not statistically significant. However, the data were from 2005, which is a year prior to the posting of the NCD. The authors essentially presumed that the organizational capabilities of hospitals in 2005 as well as when listed on the CMS website during the time of the authors’ analysis (i.e., after 2006) were the same. This presumption does not acknowledge the possibility (and the reality) that the 2006 NCD may have prompted a hospital to revise its organizational capability with regards to bariatric surgery in order to receive the designation of COE. In addition, a large majority of the analyzed data was from non-COEs (90.5%) compared to only 9.5% of data from COEs. Given this large discrepancy, it’s possible from a statistical perspective that a true difference in outcome between the two groups, if it existed, could not be detected. Another limitation is the focus on in-hospital mortality, which is an important outcome but also short-term. Lastly, an overwhelming majority of the analyzed data was from patients less than 65 years of age, which limits the usefulness of these results for elderly Medicare beneficiaries.
Nguyen 2010 conducted an analysis of discharge data from all Medicare and Medicaid patients in the University HealthSystem Consortium database from October, 2004 through September, 2007. Although the authors did not focus on the COE vs non-COE designation, this analysis was in essence an examination of COE vs non-COE outcomes since most Medicare patients after the 2006 NCD was posted would have been treated in a COE-designated facility. The authors reported results for Medicare-only patients separately from results for Medicaid patients. Compared to outcomes before the 2006 NCD, the results demonstrated a doubling in the volume of laparoscopic procedures, a decrease in the overall complication rate and no change in the in-hospital mortality rate after implementation of the 2006 NCD. It is unclear if the authors attempted to adjust their analysis for the potential confounding impact that an increasing use of, and experience with, laparoscopic procedures would have on outcomes. The authors acknowledged that the database lacked some important patient characteristics such as BMI, which prevented them from performing risk adjustment of the outcomes. In addition, the data were from only academic institutions and therefore we believe the results cannot be generalized to all facilities that perform bariatric surgery. As in the Livingston et al. study, a large majority of the analyzed data (both before and after the 2006 NCD) was from patients less than 65 years of age, which limits the usefulness of these results for elderly Medicare beneficiaries. In addition, the primary outcome was in-hospital mortality, which is an important but short-term outcome. The authors concluded that outcomes improved after the implementation of the 2006 NCD.
Birkmeyer et al. conducted an analysis of data collected from June, 2006 to September, 2009 by the Michigan Bariatric Surgery Collaborative in order to assess outcomes across hospitals based on COE status. The results revealed no significant difference in the serious complication rate between the COE and non-COE facilities. The authors, however, acknowledged that more than twice as many hospitals were COE (17) than non-COE (8), which negatively impacted the statistical power of the analysis to detect a true difference. This study also suffered from a lack of data from elderly patients; none of the reported patients were 60 years old or older.
Flum 2011 analyzed Medicare Parts A and B data from January, 2004 through December, 2008 from the ResDAC database. The authors did not focus on the COE vs non-COE designation; however this analysis was essentially an examination of COE vs non-COE outcomes since most Medicare patients after the 2006 NCD were treated in a COE-designated facility. The authors found a statistically significant decrease in the 90-day mortality rate from 1.5% before the NCD implementation to 0.7% after the NCD implementation. This statistically significant difference, however, disappeared after adjusting the statistical analysis to account for the change in types of bariatric procedures performed after the 2006 NCD compared to before the 2006 NCD. The authors concluded that the decrease in the 90-day mortality rate was due primarily to the switch to less-risky types of bariatric procedures rather than due to the use of COEs. This analysis had some limitations in common with the Livingston (2009), Nguyen (2010) and Birkmeyer (2010) studies in that the majority of the data was from patients under 65 years of age and the outcome, 90-day mortality, is slightly longer than that examined in the other three studies; however, it is still of short duration.
Kohn et al. conducted an analysis of data from 1998 to 2006 from the Nationwide Inpatient Sample database, which is an administrative database comprised of only a 20% sample of national hospitals and U.S. states. The goal was to evaluate the effects of hospital COE status on outcomes. For data collected after the February, 2006 NCD, COE status was determined by searching the CMS website. For data collected prior to the 2006 NCD, the authors determined COE status by searching the ACS and ASMBS/SRC websites; however these organizations started listing COE status in 2004 therefore it is uncertain how Kohn, et al. determined COE for the data collected from 1998 through 2003. In addition, the analysis was primarily of pre-NCD data since only a small amount of post-NCD data (i.e., from the posting of the 2006 NCD in February, 2006 to December 31, 2006) was included by the authors. The results showed a steady decrease in the overall in-hospital mortality rate for all bariatric cases over the years 1998 (the rate was 0.61%) to 2006 (0.13%), which highlights that the decrease in this mortality rate started long before the implementation of the NCD in 2006, and an overall inverse correlation between case volume and complication rate. However, the authors did not find a statistically significant association between most complications and hospital COE status. Patient characteristics such as age were not reported. Long term outcomes were not examined. Kohn et al. concluded that there is "minimal association" between outcomes and COE designation.
Kwon et al. analyzed the MarketScan Commercial Claims and Encounter Database, which is comprised of inpatient claims for patients < 65 years of age who have employer-sponsored medical insurance but not Medicare Supplemental insurance. The time frame was from 2003 to 2009 and therefore included data from before and after the 2006 NCD. After the 2006 NCD, COEs were determined by searching the Medicare Supplemental database. The deliberate use of data from nonelderly patients was based on the statistical limitations encountered by the authors in a previous analysis (Flum 2011). Hospitals that performed bariatric surgery on Medicare patients before but not after the 2006 NCD were defined to be non-COEs. Long term outcomes were not assessed. A shift to performing more laparoscopic procedures was seen in the COEs as well as in the non-COEs, which Kwon et al. referred to as "a shift to safe procedures." Using a statistical method called a difference-in-difference technique to account for this shift in procedure type as well as for varying patient risk and temporal trends, there was a significant decrease in 90-day complication rates in the COEs compared to non-COEs (p = 0.01) but no difference in inpatient mortality rate ( p = 0.1). However, the authors acknowledged that they had to make an "untestable assumption" during this analysis that introduced doubt into the results. There were some additional limitations with their analysis, such as the uncertainty about the actual accreditation status of the facility at the time of the surgery and the lack of clinical data to perform risk adjustment. The authors addressed the volume-outcome relationship for bariatric surgery, which they referred to as "controversial," by stating that “There may be other mechanisms by which the NCD may have exerted a center effect other than through shifts to higher volume hospitals. COE status through either accrediting body calls for multidisciplinary care team, education activities for patients, care pathways, mandatory reporting of outcomes and best practice infrastructure and personnel requirements. When evaluating COE effects on outcome, any of these factors may play a role, and distinguishing them is difficult if not impossible.”
Nguyen 2012 presented the results of an analysis of the University HealthSystem Consortium database. The goal was to evaluate the impact of the 2006 NCD by comparing outcomes at COEs versus non-COEs. The results showed a statistically significantly higher mean volume of surgeries performed at COEs compared to non-COEs. Only a small percentage of patients were 65 years old or older in the COEs (4.2%) and in the non-COEs (2.5%). Non-COEs were associated with a statistically significant 3.5-fold increase in observed in-hospital mortality risk compared with COEs The relative risk for overall complications was not statistically significantly different between COEs and non-COEs. In two post-hoc analyses that adjusted for COE status and procedure type, observed in-hospital mortality and overall complications were comparable between COEs and non-COEs for gastric banding; for gastric bypass surgery, overall complications were comparable between COEs and non-COEs but the observed in-hospital mortality rate was 0.06% for patients in a COE and 0.25% for patients in a non-COE; the relative risk was statistically significant (p < 0.002). Long term outcomes were not assessed. The authors acknowledged the nearly four-fold reduction of in-hospital mortality in COEs but also noted that in-hospital mortality is "rare" for both COEs and non-COEs. There are limitations with this analysis, as identified by Nguyen et al., including the larger volume of bariatric surgeries performed at COEs versus at non-COEs, which introduces doubt as to whether the difference in outcomes was due to volume or COE designation. And, as in Nguyen 2010, the data were from only academic institutions and therefore we believe the results cannot be generalized to all facilities that perform bariatric surgery.
Dimick et al. analyzed data from the State Inpatient Database, which contains data from only a quarter of the U.S. states. The goal of the analysis was to compare outcomes in Medicare patients before and after the 2006 NCD. The timeframe was from 2004 to 2009. A control group was comprised of non-Medicare patients undergoing bariatric surgery. A difference-in-difference model was used to assess the effect of COE status on outcomes. COE status was determined by referring to the CMS website. Complication rates decreased after the 2006 NCD in both Medicare and non-Medicare patients, which the authors attributed to a change in the types of procedures performed. After adjusting for procedure type and other factors, the results showed no statistically significant change in complication rates after the 2006 NCD compared to before the 2006 NCD. In another analysis designed to compare outcomes at COEs vs non-COEs, there was no statistically significant difference in complication rates at COEs vs non-COEs. Long term outcomes were not assessed. Dimick et al. concluded that there is no association between COE designation and improved outcomes after bariatric surgery.
Jafari et al. conducted an analysis of data from 2006 to 2010 from the Nationwide Inpatient Sample database, which is an administrative database comprised of discharge data from 1,000 hospitals across the U.S. The dataset used represented a 20% sample of the database. The primary goal was to examine the volume v. outcome relationship but the authors did perform a subset analysis to evaluate the effects of hospital COE status on outcomes. The outcomes were in-hospital mortality and serious morbidity. Long-term outcomes were not studied. For the analysis of volume v. outcome, hospitals were designated as a LVC if fewer than 50 laparoscopic, stapling bariatric procedures were performed per year or designated as a HVC if 50 or more procedures were performed per year. The authors found statistically significantly higher in-hospital mortality and serious morbidity rates in LVCs compared to HVCs. For the COE v. non-COE analysis, the authors reported that non-COEs had a statistically significantly higher mortality rate and a statistically significantly lower serious morbidity rate compared to COEs. These results were based on an
analysis of a subset of the dataset, specifically data from HVC, where 90% of HCVs were COE and only 10% of HCVs were non-COE. The fact that the vast majority of the data were from COEs calls into question whether the analysis had the statistical power to detect true differences between COEs and non-COEs. In addition, in their discussion the authors stated that in “high-volume nonaccredited centers, the in-hospital mortality rate was comparable with that for low-volume hospitals (0.22 vs 0.17%, respectively.” It is important to note that this comparison of the in-hospital mortality rate between the HVC/non-COE group and the LVC/COE + non-COE group was not a direct analysis reported in the article (including results of any testing for statistical significance). The authors concluded that “accreditation may have a greater impact on outcome than volume.”
Overall with regards to the comparison of outcomes at COEs versus non-COEs, the persuasiveness of four of the studies we identified (Livingston 2009; Birkmeyer 2010; Kohn 2010; Jafari 2013) is substantially weakened by a number of limitations. Results from the remaining five studies varied. Nguyen 2010 demonstrated a switch to the use of laparoscopic bariatric procedures but otherwise mixed results in outcomes with a decrease in complications after the 2006 NCD but no change in the short-term mortality rate. Flum 2011 showed the same switch to laparoscopic bariatric procedures as seen in Nguyen 2010 but also demonstrated the impact of this switch on the short-term mortality rate, which prompted the authors to suggest that the decrease in mortality was linked to the switch to laparoscopic procedures rather than the accreditation program implemented by the 2006 NCD. However, in an attempt to overcome the statistical difficulties in teasing out confounders experienced by Flum 2011, Kwon et al. performed a COE vs non-COE analysis of a commercial database that contained nonelderly patients. The switch to laparoscopic procedures was once again seen and was found in non-COEs as well as COEs. This analysis also showed mixed results, except in reverse, with a significant decrease in 90-day complication rates in COEs compared to non-COEs but no difference in short-term mortality rate.
In the analysis by Nguyen 2012, in-hospital mortality was significantly higher in non-COEs whereas the relative risk for overall complications was not significantly different in non-COEs compared to COEs. These results from Nguyen 2012 are the reverse of what was reported in Nguyen 2010. Less than five percent of patients in the COEs or non-COEs were 65 years old or older. Dimick et al. found no statistically significant differences in complication rates between COEs and non-COEs. Dimick et al. did find a decrease in complication rates in both Medicare and non-Medicare patients after the 2006 NCD, which they attributed to a change in bariatric procedure mix to the use of more laparoscopic rather than open procedures. Much like in Kwon et al., Dimick et al. employed statistical methods in an attempt to adjust for the observed change in procedure mix, which resulted in the loss of a statistically significant change in complication rates. As for the other seven studies, long term outcomes were not assessed.
No evidence-based guidelines were found with regards to facility accreditation. The ASMBS and the ACS have a unified position statement (in favor of COEs) via their national bariatric surgery accreditation program, which is under development. No other position statements were found.
During our review, we considered additional studies that solely addressed the impact of bariatric surgical volume on outcomes. These studies were reviewed and are included in the bibliography. We did not find any evidence-based guidelines regarding the volume-outcome relationship, however. While there is evidence that shows higher volumes has a positive impact on bariatric surgical outcomes, this effect is not isolated to bariatric surgery. There is a precedent in surgical practice and the literature for considering the volume-outcome relationship. Markar et al. noted that evidence has been published in several surgical specialties including pancreatic surgery, colorectal cancer resection and carotid endarterectomy.
A volume requirement is one component of the standards identified in the 2006 CMS decision memorandum for bariatric surgery, however it is only one requirement and it is not the sole determinant for COE designation, as noted by Kwon et al. Despite the recent decision by ASMBS and ACS to lower the annual volume requirement to 50 for the unified accreditation program, the evidence does not suggest to us that the ideal annual volume has been determined.
Our evidence review was focused on the benefit of the facility certification requirement, however during our review of that evidence we did not identify any evidence that would lead us to expand our evidentiary review or change our determination made in 2006 that the open and laparoscopic Roux-en-Y gastric bypass (RYGBP), laparoscopic adjustable gastric banding (LAGB), and open and laparoscopic biliopancreatic diversion with duodenal switch (BPD/DS) are reasonable and necessary for Medicare beneficiaries who have a body-mass index (BMI) ≥ 35, have at least one co-morbidity related to obesity, and have been previously unsuccessful with medical treatment for obesity.
Since implementation of the 2006 NCD, we found a handful of studies in the literature that evaluated the utility of facility certification/COE designation. As a result, there is little evidence that the requirement for facility certification/COE designation for coverage of approved bariatric surgery procedures impacts outcomes for Medicare beneficiaries. The studies identified conducted a retrospective analysis on data from an administrative (i.e., non-clinical) database; hence, the quality of the evidence from these studies is not as robust as that produced in a clinical trial. The evidence from all of the studies reviewed however is primarily from patients less than 65 years old. CMS claims data for 2009 and 2010 shows that approximately four thousand bariatric surgery procedures were performed on Medicare beneficiaries over 65 years of age in each of those years. We believe this represents sufficient numbers to be included in studies looking at outcomes of bariatric surgery procedures. The evidence that we did find contained mixed results, but the overall body of evidence supports a conclusion of no consistent statistical or clinically meaningful difference. We found no evidence to suggest a worsening of outcomes.
Therefore, we believe the available evidence is sufficient to determine that the requirement for facility certification/COE designation for coverage of approved bariatric surgery procedures does not provide improved outcomes for Medicare beneficiaries.
The factors that influenced the CMS decision in 2006 to establish the facility certification requirement have changed. In our 2006 review we identified concerns about higher mortality rates for bariatric surgery in the Medicare population over 65 years of age. In addition, there was a rapid growth of bariatric surgery procedures and the establishment of standards for the field of bariatric surgery was new. Since that 2006 determination, bariatric surgery has experienced a trend toward less invasive procedures and lower mortality and complication rates. The rate of growth in bariatric surgery has leveled off. Bariatric surgery is generally disseminated in the medical community at large now. Generally accepted standards in bariatric surgery have been established and we expect will continue to evolve to address quality improvement in this field.
In light of the lack of sufficient evidence that the certified/COE bariatric facilities have provided improved outcomes in Medicare beneficiaries since the 2006 NCD, CMS has decided to eliminate the requirement for facility certification/COE designation. Given the history of two accreditation programs (i.e., the ASMBS and the ACS) as well as the ongoing establishment of a unified accreditation program by these two professional societies, we feel it is important the surgical community at large should continue to explore, define and measure the utility of bariatric surgery facility accreditation and quality improvement initiatives. In particular, we continue to be focused on outcomes, especially longer-term outcomes.
In addition, our review, while focused on the evidence for facility certification, did not identify any evidence that would support a change to our reasonable and necessary coverage and non-coverage determinations made in 2006 for the specific procedures identified in the NCD. However, since the evidence did not support a benefit from the facility certification requirement, the open and laparoscopic Roux-en-Y gastric bypass (RYGBP), laparoscopic adjustable gastric banding (LAGB), and open and laparoscopic biliopancreatic diversion with duodenal switch (BPD/DS) procedures are considered reasonable and necessary for Medicare beneficiaries who meet the patient specific criteria even at facilities that are not certified.
As identified in Section III.A of this document, at this time we also plan to make numerous changes to the NCD for bariatric surgery. These changes include changing the title to clearly reflect the scope of the bariatric surgery NCD and adding a statement to make it clear in the manual that under the existing policy the local Medicare Administrative Contractors have the authority to make coverage decisions for any bariatric surgery procedures not specifically identified as covered or non-covered by an NCD. In addition, we plan at this time to consolidate all of the bariatric surgery NCDs by subsuming related sections 40.5, 100.8, 100.11 and 100.14 into section 100.1. This is an administrative change and there is no change in the coverage due to the consolidation. We believe this administrative change will make it easier for the public to access our policy on bariatric surgery.
The concern regarding the increase in obesity in the United States is well documented. The Centers for Disease Control and Prevention (CDC) notes that in 2009 - 2010 more than 35% of U.S. men and women were obese (http://www.cdc.gov/nchs/data/databriefs/db82.htm). In addition, "There was no significant difference in prevalence between men and women at any age. Overall, adults aged 60 and over were more likely to be obese than younger adults. Among men there was no significant difference in obesity prevalence by age. Among women, however, 42.3% of those aged 60 and over were obese compared with 31.9% of women aged 20–39."
In a study published in 2010, Flegal et al. found that the prevalence of obesity showed "significant variation by racial and ethnic groups." In addition, the prevalence exceeded "30% in most age and sex groups except for men aged 20 to 39 years. Among men, age-adjusted obesity prevalence was 32.2% overall (95% confidence interval [CI], 29.5%-35.0%) and within racial and ethnic groups ranged from 31.9% (95% CI, 28.1%-35.7%) among non-Hispanic white men to 37.3% (95% CI, 32.3%-42.4%) among non-Hispanic black men. For women, the age-adjusted prevalence was 35.5% (95% CI, 33.2%-37.7%), ranging from 33.0% (95% CI, 29.3%-36.6%) among non-Hispanic white women to 49.6% (95% CI, 45.5%-53.7%) among non-Hispanic black women. The age-adjusted prevalence of overweight and obesity combined was 68.0% (95% CI, 66.3%-69.8%) overall, 72.3% (95% CI, 70.4%-74.1%) among men, and 64.1% (95% CI, 61.3%-66.9%) among women." The authors also noted that "for both men and women, the likelihood of being obese was significantly higher in the age group of 40-59 years (OR for men, 1.46 [95% CI, 1.29-1.66]; OR for women, 1.50 [95% CI, 1.31-1.72]) and in the age group of 60 years or older (OR for men, 1.35 [95% CI, 1.19-1.54]; OR for women, 1.26 [95% CI, 1.11-1.44]) than among those in the age group of 20-39 years. Relative to non-Hispanic whites, the likelihood of being obese was significantly greater among non-Hispanic blacks (OR for men, 1.13 [95% CI, 1.01-1.27]; OR for women, 2.26 [95% CI, 2.02-2.51]) and for Mexican American women (OR, 1.53; 95% CI, 1.31-1.78), but not for Mexican American men (OR, 1.01; 95% CI, 0.85-1.19)." (http://jama.jamanetwork.com/article.aspx?articleid=185235)
Regarding concerns about disparity in access to care, Nguyen 2010 stated that the 2006 NCD "did not impede access to care." However, Livingston and Burchell 2010 stated, “Center of Excellence requirements have increased the travel distance required for Medicare patients. Prior research has shown that outcomes at COEs are no different than those at non-COEs suggesting that the reduced access to care resulting from requiring COE status is not beneficial.” Dimick 2013 mentioned that limiting access to care may have been an unintended consequence of the CMS bariatric surgery facility certification requirement. A number of commenters identified access to care as a concern. Access to care issues are typically encountered by the poorer and disadvantaged populations so it is an important consideration for our Medicare beneficiaries.
The CMS has determined that the evidence is sufficient to conclude that continuing the requirement for certification for bariatric surgery facilities would not improve health outcomes for Medicare beneficiaries. Therefore, CMS has decided to remove this certification requirement.
CMS also decided that no changes be made to the bariatric surgery procedures that are deemed covered in section 100.1 of the NCD Manual. The evidence continues to support that open and laparoscopic Roux-en-Y gastric bypass (RYGBP), laparoscopic adjustable gastric banding (LAGB), and open and laparoscopic biliopancreatic diversion with duodenal switch (BPD/DS) continue to be reasonable and necessary for Medicare beneficiaries who have a body-mass index (BMI) ≥ 35, have at least one co-morbidity related to obesity, and have been previously unsuccessful with medical treatment for obesity.
Lastly, we decided to change the title to better reflect the scope of the NCD and to make it clear in the manual that under the existing policy the local Medicare Administrative Contractors have the authority to make coverage decisions for certain patients for any bariatric surgery procedures not specifically identified as covered or non-covered by an NCD.
In addition, to the decision above, CMS is renumbering and consolidating its manual for section 100.1. This is an administrative change only to make it easier for the public to read and understand the NCD manual. There is no change in coverage because of the renumbering and consolidation.
- The additional NCDs related to bariatric surgery will be consolidated and subsumed into section 100.1 of the NCD Manual. These include sections 40.5, 100.8, 100.11 and 100.14.
The changes to the manual are reflected in attachment Appendix C.
General Methodological Principles of Study Design
When making national coverage determinations, CMS evaluates relevant clinical evidence to determine whether or not the evidence is of sufficient quality to support a finding that an item or service falling within a benefit category is reasonable and necessary for the diagnosis or treatment of illness or injury or to improve the functioning of a malformed body member. The critical appraisal of the evidence enables us to determine whether: 1) the specific assessment questions can be answered conclusively; and 2) the intervention will improve health outcomes for patients. An improved health outcome is one of several considerations in determining whether an item or service is reasonable and necessary.
CMS divides the assessment of clinical evidence into three stages: 1) the quality of the individual studies; 2) the relevance of findings from individual studies to the Medicare population; and 3) overarching conclusions that can be drawn from the body of the evidence on the direction and magnitude of the intervention’s risks and benefits.
The issues presented here represent a broad discussion of the issues we consider when reviewing clinical evidence. However, it should be noted that each coverage determination has unique methodological aspects.
1. Assessing Individual Studies
Methodologists have developed criteria to determine weaknesses and strengths of clinical research. Strength of evidence generally refers to: 1) the scientific validity underlying study findings regarding causal relationships between health care interventions and health outcomes; and 2) the reduction of bias. In general, some of the methodological attributes associated with stronger evidence include those listed below:
- Use of randomization (allocation of patients to either intervention or control group) in order to minimize bias.
- Use of contemporaneous control groups (rather than historical controls) in order to ensure comparability between the intervention and control groups.
- Prospective (rather than retrospective) studies to ensure a more thorough and systematical assessment of factors related to outcomes.
- Larger sample sizes in studies to help ensure adequate numbers of patients are enrolled to demonstrate both statistically significant as well as clinically significant outcomes that can be extrapolated to the Medicare population. Sample size should be large enough to make chance an unlikely explanation for what was found.
- Masking (blinding) to ensure patients and investigators do not know to which group patients were assigned (intervention or control). This is important especially in subjective outcomes, such as pain or quality of life, where enthusiasm and psychological factors may lead to an improved perceived outcome by either the patient or assessor.
Regardless of whether the design of a study is a randomized controlled trial, a non-randomized controlled trial, a cohort study or a case-control study, the primary criterion for methodological strength or quality is the extent to which differences between intervention and control groups can be attributed to the intervention studied. This is known as internal validity. Various types of bias can undermine internal validity. These include:
- Different characteristics between patients participating and those theoretically eligible for study but not participating (selection bias)
- Co-interventions or provision of care apart from the intervention under evaluation (confounding)
- Differential assessment of outcome (detection bias)
- Occurrence and reporting of patients who do not complete the study (attrition bias)
In principle, rankings of research design have been based on the ability of each study design category to minimize these biases. A randomized controlled trial minimizes systematic bias (in theory) by selecting a sample of participants from a particular population and allocating them randomly to the intervention and control groups. Thus, randomized controlled studies have been typically assigned the greatest strength, followed by non-randomized clinical trials and controlled observational studies. The following is a representative list of study designs (some of which have alternative names) ranked from most to least methodologically rigorous in their potential ability to minimize systematic bias:
- Randomized controlled trials
- Non-randomized controlled trials
- Prospective cohort studies
- Retrospective case control studies
- Cross-sectional studies
- Surveillance studies (e.g., using registries or surveys)
- Consecutive case series
- Single case reports
When there are merely associations but not causal relationships between a study’s variables and outcomes, it is important not to draw causal inferences. Confounding refers to independent variables that systematically vary with the causal variable. This distorts measurement of the outcome of interest because its effect size is mixed with the effects of other extraneous factors. For observational, and in some cases randomized controlled trials, the method in which confounding factors are handled (either through stratification or appropriate statistical modeling) are of particular concern. For example, in order to interpret and generalize conclusions to our population of Medicare
patients, it may be necessary for studies to match or stratify their intervention and control groups by patient age or co-morbidities.
Methodological strength is, therefore, a multidimensional concept that relates to the design, implementation and analysis of a clinical study. In addition, thorough documentation of the conduct of the research, particularly study’s selection criteria, rate of attrition and process for data collection, is essential for CMS to adequately assess the evidence.
2. Generalizability of Clinical Evidence to the Medicare Population
The applicability of the results of a study to other populations, settings, treatment regimens, and outcomes assessed is known as external validity. Even well-designed and well-conducted trials may not supply the evidence needed if the results of a study are not applicable to the Medicare population. Evidence that provides accurate information about a population or setting not well represented in the Medicare program would be considered but would suffer from limited generalizability.
The extent to which the results of a trial are applicable to other circumstances is often a matter of judgment that depends on specific study characteristics, primarily the patient population studied (age, sex, severity of disease, and presence of co-morbidities) and the care setting (primary to tertiary level of care, as well as the experience and specialization of the care provider). Additional relevant variables are treatment regimens (dosage, timing, and route of administration), co-interventions or concomitant therapies, and type of outcome and length of follow-up.
The level of care and the experience of the providers in the study are other crucial elements in assessing a study’s external validity. Trial participants in an academic medical center may receive more or different attention than is typically available in non-tertiary settings. For example, an investigator’s lengthy and detailed explanations of the potential benefits of the intervention and/or the use of new equipment provided to the academic center by the study sponsor may raise doubts about the applicability of study findings to community practice.
Given the evidence available in the research literature, some degree of generalization about an intervention’s potential benefits and harms is invariably required in making coverage decisions for the Medicare population. Conditions that assist us in making reasonable generalizations are biologic plausibility, similarities between the populations studied and Medicare patients (age, sex, ethnicity and clinical presentation), and similarities of the intervention studied to those that would be routinely available in community practice.
A study’s selected outcomes are an important consideration in generalizing available clinical evidence to Medicare coverage determinations because one of the goals of our determination process is to assess health outcomes. We are interested in the results of changed patient management not just altered management. These outcomes include resultant risks and benefits such as increased or decreased morbidity and mortality. In order to make this determination,
it is often necessary to evaluate whether the strength of the evidence is adequate to draw conclusions about the direction and magnitude of each individual outcome relevant to the intervention under study. In addition, it is important that an intervention’s benefits are clinically significant and durable, rather than marginal or short-lived.
If key health outcomes have not been studied or the direction of clinical effect is inconclusive, we may also evaluate the strength and adequacy of indirect evidence linking intermediate or surrogate outcomes to our outcomes of interest.
3. Assessing the Relative Magnitude of Risks and Benefits
Generally, an intervention is not reasonable and necessary if its risks outweigh its benefits. Health outcomes are one of several considerations in determining whether an item or service is reasonable and necessary. For most determinations, CMS evaluates whether reported benefits translate into improved health outcomes. CMS places greater emphasis on health outcomes actually experienced by patients, such as quality of life, functional status, duration of disability, morbidity and mortality, and less emphasis on outcomes that patients do not directly experience, such as intermediate outcomes, surrogate outcomes, and laboratory or radiographic responses. The direction, magnitude, and consistency of the risks and benefits across studies are also important considerations. Based on the analysis of the strength of the evidence, CMS assesses the relative magnitude of an intervention or technology’s benefits and risk of harm to Medicare beneficiaries.
CMS does from time to time include requirements for facility and/or physician standards, or certain certification requirements in our NCDs; however, we exercise this option after considered counsel and cognizant of the responsibility such requirements establish. Some of the considerations that may inform our decision to include facility and/or physician standards, or certification requirements are: intended patients who are medically fragile undergoing high risk procedures; procedures that are new or not generally disseminated in the medical community at large; technically complex procedures; procedures experiencing a rapid growth in the medical community before the opportunity for the establishment of generally accepted standards; procedures that impose what we believe to be a significantly higher risk for our Medicare beneficiaries. While this is not intended to be an all-inclusive list of what may inform CMS’s decision to include facility and/or physician standards, or certification requirements, it is provided to give some insight into our decision making process. Ultimately, it is the convincing nature of the circumstances and/or the evidence surrounding the item or service under review that guides CMS to conclude that such standards and/or certification requirements will benefit our Medicare beneficiaries.
References from Comments on PDM
References are listed as provided by the commenter. Some references were submitted by more than one commenter.
Encinosa from the Agency for Healthcare Research and Quality detailed in a 2009 Medical Care article the steep decline in complications following the NCD including large reductions in-patient, 30-day and 180-day complications respectively, 37%, 24%, and 21%.
Nguyen in a 2010
Nguyen in a 2012 Journal of the American College of Surgeons (JACS)
Kwon in a 2012 Surgery for Obesity and Related Diseases
2013 Nguyen Surgical Endoscopy.
2005 American Surgeon article, Poulose 2006
Archives of Surgery publication by Livingston
2006 American Surgeon article by Nguyen
2011 Archives of Surgery publication, Nguyen et al 2012 SOARD paper by Gould et al,
2008 Annals of Surgery article by Perry et
2011 Flum Annals of Surgery article,
Encinosa from the Agency for Healthcare Research and Qualitydetailed in a 2009
Nguyen in a 2010 Archives of Surgery
Nguyen in a 2012 Journal of the American College of Surgeons (JACS)
Kwon in a 2012 Surgery for Obesity and Related Diseases
2011 Flum study
2013 Nguyen Surgical Endoscopy study
2005 American Surgeon article, Poulose
2006 Archives of Surgery publication by Livingston,
2006 American Surgeon article by Nguyen
2011 Archives of Surgery publication, Nguyen et al
2012 SOARD paper by Gould et al,
2008 Annals of Surgery article by Perry
2013 Dimick JAMA article,
Mechanic SOARD 2008
Wadden & Sarwer,SOARD 2006
 Paul F. Hogan et. al, “Cost Effectiveness Analysis of Anesthesia Providers.” Nursing Economic$. 2010; 28:159-169.
 B. Dulisse and J. Cromwell, “No Harm Found When Nurse Anesthetists Work Without Physician Supervision.” Health Affairs. 2010; 29: 1469-1475.
 U.S. Government Accountability Office (GAO). Medicare Physician Payments: Medicare and Private Payment Differences for Anesthesia Services. Report to Subcommittee on Health, Committee on Ways and Means, U.S. House of Representatives. GAO-07-463. July 2007;15. http://www.gao.gov/new.items/d07463.pdf.
 See http://www.cms.gov/medicare-coverage-database/staticpages/public-comment.aspx?commentID=25415&ReportType=nca.
Nguyen in a 2012 Journal of the American College of Surgeons (JACS)
2011 Flum study
Murr MM, Martin T, Haines K, Torrella T, Dragotti R, Kandil A, Gallagher SF, Harmsen S. Ann Surg. 2007 May;245(5):699-706
The 2011 Flum study
Nguyen’s recent Surgical Endoscopy study “Volume and Outcome relationship in Bariatric Surgery in the Laparoscopic Era,”
1999-2000 (Davis MM, Slish K, Chao C, Cabana MD. National trends in bariatric surgery, 1996-2002. Arch Surg. 2006 Jan;141(1):71-4) Early mortality among Medicare beneficiaries undergoing bariatric surgical procedures. JAMA. 2005;294:1903–1908)
Flum has illustrated this already (Ann Surg 2011;254:860–865).
Yuan SOARD 2009
JAMA Dimick 2013
Morton/Nguyen commentary (SOARD 2013)
Surgical Endoscopy Nguyen 2013 study “Volume and Outcome relationship in Bariatric Surgery in the Laparoscopic Era,”
(Mechanic SOARD 2008).
(Wadden & Sarwer, SOARD 2006).
CMS and Facility Certification
“Institutes of Quality Bariatric Surgery Facilities”
Anthem Blue Cross and Blue Shield / Wellpoint
“Blue Distinction Centers for Bariatric Surgery”
“3 Star Quality Bariatric Centers”
United Healthcare / Optum Health
2008 Obesity Review article, Neovius and colleagues
Flegal in a 2010 JAMA
Segev, J Am Soc Nephrol, 2008
American Surgeon, Carbonell et al reported in 2005
2005 American Surgeon article, Poulose
2006 Archives of Surgery publication by Livingston
2006 American Surgeon article by Nguyen,
SOARD 2009 article, Yuan
2011 Archives of Surgery publication, Nguyen et al
2012 SOARD paper by Gould et al,
2008 Annals of Surgery article by Perry et al,
2013 Nguyen Surgical Endoscopy paper.
Adams noted in JAMA 2000,
Zevin in Annals of Surgery 2012
2010 JAMA Birkmeyer
Courcoulas, Surgery 2003;
Liu, American Surgeon 2003;
Flum, JACS 2004; Nguyen, Annals of Surgery 2004;
Smith, SOARD 2010;
Flum, JAMA 2005;
Weller, JACS 2007;
Murr, Annals of Surgery 2007;
Parker, Surgical Endoscopy 2007;
Kelles, Obesity Surgery 2009;
Birkmeyer, JAMA 2010.
This information is representative of Medicare's final national coverage determination (NCD) for implementation purposes only. The information is subject to formal revisions and formatting changes prior to the release of the final NCD implementation contractor instructions and publication in the Medicare National Coverage Determinations Manual.
100.1 - Bariatric Surgery for Treatment of Co-Morbid Conditions Related to Morbid Obesity
(Rev. , Issued: , Effective: , Implementation: )
Obesity may be caused by medical conditions such as hypothyroidism, Cushing's disease, and hypothalamic lesions, or can aggravate a number of cardiac and respiratory diseases as well as diabetes and hypertension. Non-surgical services in connection with the treatment of obesity are covered when such services are an integral and necessary part of a course of treatment for one of these medical conditions.
In addition, supplemented fasting is a type of very low calorie weight reduction regimen used to achieve rapid weight loss. The reduced calorie intake is supplemented by a mixture of protein, carbohydrates, vitamins, and minerals. Serious questions exist about the safety of prolonged adherence for 2 months or more to a very low calorie weight reduction regimen as a general treatment for obesity, because of instances of cardiopathology and sudden death, as well as possible loss of body protein.
Bariatric surgery procedures are performed to treat comorbid conditions associated with morbid obesity. Two types of surgical procedures are employed. Malabsorptive procedures divert food from the stomach to a lower part of the digestive tract where the normal mixing of digestive fluids and absorption of nutrients cannot occur. Restrictive procedures restrict the size of the stomach and decrease intake. Surgery can combine both types of procedures.
The following are descriptions of bariatric surgery procedures:
1. Roux-en-Y Gastric Bypass (RYGBP)
The RYGBP achieves weight loss by gastric restriction and malabsorption. Reduction of the stomach to a small gastric pouch (30 cc) results in feelings of satiety following even small meals. This small pouch is connected to a segment of the jejunum, bypassing the duodenum and very proximal small intestine, thereby reducing absorption. RYGBP procedures can be open or laparoscopic.
2. Biliopancreatic Diversion with Duodenal Switch (BPD/DS)
The BPD achieves weight loss by gastric restriction and malabsorption. The stomach is partially resected, but the remaining capacity is generous compared to that achieved with RYGBP. As such, patients eat relatively normal-sized meals and do not need to restrict intake radically, since the most proximal areas of the small intestine (i.e., the duodenum and jejunum) are bypassed, and substantial malabsorption occurs. The partial BPD/DS is a variant of the BPD procedure. It involves resection of the greater curvature of the stomach, preservation of the pyloric sphincter, and transection of the duodenum above the ampulla of Vater with a duodeno-ileal anastomosis and a lower ileo-ileal anastomosis. BPD/DS procedures can be open or laparoscopic.
3. Adjustable Gastric Banding (AGB)
The AGB achieves weight loss by gastric restriction only. A band creating a gastric pouch with a capacity of approximately 15 to 30 cc’s encircles the uppermost portion of the stomach. The band is an inflatable doughnut-shaped balloon, the diameter of which can be adjusted in the clinic by adding or removing saline via a port that is positioned beneath the skin. The bands are adjustable, allowing the size of the gastric outlet to be modified as needed, depending on the rate of a patient’s weight loss. AGB procedures are laparoscopic only.
4. Sleeve Gastrectomy
Sleeve gastrectomy is a 70%-80% greater curvature gastrectomy (sleeve resection of the stomach) with continuity of the gastric lesser curve being maintained while simultaneously reducing stomach volume. In the past, sleeve
gastrectomy was the first step in a two-stage procedure when performing RYGBP, but more recently has been offered as a stand-alone surgery. Sleeve gastrectomy procedures can be open or laparoscopic.
5. Vertical Gastric Banding (VGB)
The VGB achieves weight loss by gastric restriction only. The upper part of the stomach is stapled, creating a narrow gastric inlet or pouch that remains connected with the remainder of the stomach. In addition, a non-adjustable band is placed around this new inlet in an attempt to prevent future enlargement of the stoma (opening). As a result, patients experience a sense of fullness after eating small meals. Weight loss from this procedure results entirely from eating less. VGB procedures are essentially no longer performed.
B. Nationally Covered Indications
Effective for services performed on and after February 21, 2006, Open and laparoscopic Roux-en-Y gastric bypass (RYGBP), open and laparoscopic Biliopancreatic Diversion with Duodenal Switch (BPD/DS), and laparoscopic adjustable gastric banding (LAGB) are covered for Medicare beneficiaries who have a body-mass index ≥ 35, have at least one co-morbidity related to obesity, and have been previously unsuccessful with medical treatment for obesity.
Effective for dates of service on and after February 21, 2006, these procedures are only covered when performed at facilities that are: (1) certified by the American College of Surgeons as a
Level 1 Bariatric Surgery Center (program standards and requirements in effect on February 15, 2006); or (2) certified by the American Society for Bariatric Surgery as a Bariatric Surgery Center of Excellence (program standards and
requirements in effect on February 15, 2006). Effective for dates of service on and after September 25, 2013, facilities are no longer required to be certified.
Effective for services performed on and after February 12, 2009, the Centers for Medicare & Medicaid Services (CMS) determines that Type 2 diabetes mellitus is a co-morbidity for purposes of this NCD.
A list of approved facilities and their approval dates are listed and maintained on the CMS Coverage Web site at http://www.cms.gov/Center/Special-Topic/Medicare-Coverage-Center.html, and published in the Federal Register for services provided up to and including date of service September 24, 2013.
C. Nationally Non-Covered Indications
Treatments for obesity alone remain non-covered.
Supplemented fasting is not covered under the Medicare program as a general treatment for obesity (see section D. below for discretionary local coverage).
The following bariatric surgery procedures are non-covered for all Medicare beneficiaries:
Open adjustable gastric banding;
Open sleeve gastrectomy; and,
Laparoscopic sleeve gastrectomy (prior to June 27, 2012)
Open and laparoscopic vertical banded gastroplasty.
Intestinal bypass surgery
Gastric balloon for treatment of obesity
Effective for services performed on and after June 27, 2012, Medicare Administrative Contractors acting within their respective jurisdictions may determine coverage of stand-alone laparoscopic sleeve gastrectomy (LSG) for the treatment of co-morbid conditions related to obesity in Medicare beneficiaries only when all of the following conditions a.-c. are satisfied.
a. The beneficiary has a body-mass index (BMI) ≥ 35 kg/m2,
b. The beneficiary has at least one co-morbidity related to obesity, and,
c. The beneficiary has been previously unsuccessful with medical treatment for obesity.
The determination of coverage for any bariatric surgery procedures that are not specifically identified in an NCD as covered or non-covered, for Medicare beneficiaries who have a body-mass index ≥ 35, have at least one
co-morbidity related to obesity, and have been previously unsuccessful with medical treatment for obesity, is left to the local Medicare Administrative Contractor.
Where weight loss is necessary before surgery in order to ameliorate the complications posed by obesity when it coexists with pathological conditions such as cardiac and respiratory diseases, diabetes, or hypertension (and other more conservative techniques to achieve this end are not regarded as appropriate), supplemented fasting with adequate monitoring of the patient is eligible for coverage on a case-by-case basis or pursuant to a local coverage determination. The risks associated with the achievement of rapid weight loss must be carefully balanced against the risk posed by the condition requiring surgical treatment.
(This NCD last reviewed XXXX .)