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Centers for Medicare & Medicaid Services

MEDCAC Meeting 9/25/2002 - Deep Brain Stimulation for Parkinson's Disease (Executive Committee)

Deep brain stimulation involves the stereotactic placement of an electrode in the brain for the treatment of certain disorders associated with Parkinson's syndrome. The Food and Drug Administration (FDA) has approved the Medtronic ActivaTM Tremor Control Therapy device for unilateral thalamic stimulation for the suppression of tremor in the upper extremity for patients who are diagnosed with essential tremor or Parkinsonian tremor not controlled by medication and where the tremor constitutes a significant functional disability. Subsequently, bilateral stimulation in the subthalamic nucleus has been used for multiple symptoms of Parkinson's disease.

Currently, FDA is reviewing the safety and effectiveness of the bilateral use of this device in the subthalamic nucleus. Section 35-20 of the Medicare Coverage Issues (CIM) Manual states that "Medicare coverage of deep brain stimulation by implantation of a stimulator device is not prohibited. Therefore, coverage of deep brain stimulation provided by an implanted deep brain stimulator is at the carrier's discretion."

Requestor has asked that CMS issue a national coverage decision for the bilateral use of this device in the subthalamic nucleus. CMS will review the scientific evidence and determine if this procedure would be a reasonable and necessary service for Medicare beneficiaries.

Federal Register Notice

8:00 AM – 4:30 PM
Baltimore Convention Center— Rooms 321-322

Harold C. Sox, M.D., Chairperson
Robert H. Brook, M.D., Vice Chairperson
Sean R. Tunis, MD, MSc, Acting Deputy Director, Office of Clinical Standards and Quality
Janet A. Anderson, Executive Secretary

7:30 – 8:00 AM


8:00 – 8:15 AM

Opening Remarks—J. Anderson / S.Tunis

8:15 – 8:30 AM

Charge to the Committee H.Sox

8:30 – 8:50 AM

Summary of Medical and Surgical Procedures (Med/Surg) panel findings Deep Brain Stimulation for Parkinson’s Disease Alan Garber, M.D., Ph.D, Chairperson Med/Surg panel

8:50 – 9:10 AM

Scheduled Public Comments

9:10 – 9:25 AM

Open Public Comments

9:25 – 10:00 AM

Discussion and Vote concerning Med/Surg panel findings

10:00 – 10:15 AM


10:15 – 11:30 AM

CMS Referral Guidelines for MCAC issues S. Tunis/ Steve Sheingold

11:30 – 11:45 PM

Open Public Comments

* * * * * * * * * *

11:45 – 12:45 PM


* * * * * * * * * *

12:45 – 1:00 PM

Introduction to Assessing Evidence Discussion- H. Sox

1:00 – 2:45 PM

Assessing Evidence concerning Diseases that Affect Small Populations

2:45 – 3:15 PM

Scheduled Public Comments

3:15 – 3:30 PM

Open Public Comments

3:30 – 4:00 PM

Committee Comments on Assessing Evidence

4:00 – 4:30 PM

Closing Remarks- J. Anderson / S.Tunis

4:30 PM


Minutes of September 25, 2002 Meeting

Baltimore Convention Center
One West Pratt Street
Baltimore, Maryland


Harold C. Sox, M.D.

Robert H. Brook, Ph.D.

Janet Anderson
Executive Secretary

Voting Members
Thomas V. Holohan, M.A., M.D.
Leslie P. Francis, M.D., J.D.
John H. Ferguson, M.D.
Robert L. Murray, Ph..D.
Alan M. Garber, M.D.
Michael D. Maves, M.D.
Ronald M. Davis, M.D.
Barbara J. McNeil, M.D.
Wade Aubry, M.D.

CMS Liaison
Sean R. Tunis, M.D.

Consumer Representative
Linda A. Bergthold, Ph.D.

Industry Representative
Randel E. Richner, M.P.H.

Wednesday, September 25, 2002, 8:13 a.m.

The Executive Committee (EC) of the Medicare Coverage Advisory Committee (MCAC) met on September 25, 2002, to review and act upon the recommendations of the Medical and Surgical Procedures panel resulting from their June 12, 2002 meeting; to discuss CMS referral guidelines for MCAC issues; and begin a discussion of assessing evidence for diagnostic tests used in diseases that affect small populations of patients. Following ratification of the Medical and Surgical Procedures (MSP) panel’s recommendations, the Executive Committee considered a non-agenda item- an amendment to the Guidelines for Evaluating Clinical Effectiveness (the Guidelines) that added a new category for describing the size of the health effect of the technology.

The meeting began with the introduction of the EC, a reading of the conflict of interest statement, and a charge to the committee by the Chair.

Deep Brain Stimulation for Parkinson’s Disease.   The Chair of the MSP panel Alan Garber, MD summarized the recommendations forwarded by the panel concerning the use of Deep Brain Stimulation (DBS) for Parkinson’s disease and reported the panel discussion regarding the Guidelines. Dr.Garber summarized for the Committee the discussion that led the panel to amend the voting questions given to the panel by CMS, and discussions about size of the health effect of the technology. A motion was made to approve the recommendations from the MSP panel concerning DBS for Parkinson’s disease. The motion carried with one against. Dr. Garber stated that the panel members felt that the DBS technology was extremely important, but does not rise to the level of “breakthrough technology”, or technology which is now the standard of care. However, the size of the health effect was deemed by the panel to be greater than the Guideline’s alternative, “more effective” which applies to technologies that improve health outcomes by a significant, albeit small margin as compared to established services or medical items.

A motion was made by the Committee to approve the recommendations of the MSP panel concerning the use of DBS for Parkinson’s Disease, but to define what is referred to in the panel’s recommendation as “the well-defined set of Medicare patients for whom this conclusion applies”. The Committee added the language:

    “The Executive Committee believes that the well-defined set of Medicare patients for whom this conclusion applies is the group of patients who have reached maximum benefit from medical treatment and continue to have unacceptable symptoms from disease or increasing side effects from medication.”

Following discussion, the motion carried, with one vote against.

Change to Interim Guidelines.   Although not on the printed agenda, the Chair Harold Sox, MD. introduced discussion on whether the Guidelines should be amended to add the size of health effect category proposed by the MSP panel. Following this discussion, it was moved and seconded that the following category of “size of health effect” be added to the Guidelines for future MCAC panels to consider:

    substantially more effective: The new intervention improves health outcomes by a substantial margin as compared with established services or medical items.

The motion carried with a unanimous vote.

CMS Referral Guidelines for MCAC Issues.   The committee heard from Sean Tunis, MD. and Steven Sheingold, PhD. concerning the criteria whereby issues are referred to the MCAC for review. An extensive discussion followed, during which the committee also heard from Deborah Zarin, MD., from the Center for Practice and Technology Assessment at the Agency for Healthcare Research and Quality (AHRQ), on how AHRQ selects evidence-based practice centers to conduct technology assessments for medical items or services as requested by CMS. The committee expressed a desire that CMS continue to expand the transparency of the coverage process and maintain the timeliness of the coverage decisions. The committee also expressed a keen interest in all coverage decisions being considered by CMS, and requested that the Committee receive updates on new coverage requests regardless of MCAC involvement and where possible, new local coverage decisions as well. The committee was informed of the CMS list serve program, which tracks all of the new national coverage issues being considered, and is available to the public. Dr. Tunis stated that all MCAC members would be informed how to enroll in the list serve according to the degree of information they want to receive. All MCAC members with current valid email addresses are enrolled in the CMS list serve for coverage updates.

Following lunch, Dr. Tunis explained CMS’s rationale in seeking external technology assessments and the specific criteria used to decide to refer something for MCAC review. It was the consensus of the committee that further discussion should be held at a future meeting concerning these criteria, especially since a few members of the Committee have great interest in collaborating with CMS on these criteria. Dr. Tunis stated that with the assistance of Randel Richner, Leslie Francis, MD and Ron Davis, MD he would work on a refinement of the proposed criteria and bring the revised criteria to a future MCAC meeting for further discussion.

Discussion on Assessing Diagnostic Tests for Rare Diseases.   During the remainder of the afternoon session, the Committee discussed the process and procedure for assessing evidence for diseases that affect small populations. The Chair introduced the discussion and focused the topic to only include diagnostic testing technologies, and posed the question to the Committee as to whether a less rigorous standard of evidence than the one already detailed in the Guidelines should be considered for diseases that affect small populations in light of the inherent difficulty in enrolling patients in the clinical trials. Committee members discussed the various barriers to research in these diseases, mainly the difficulty in coordinating research efforts in cases of extremely rare disease and geographical limitations that introduce selection bias to the smaller trials. The panel also noted that in multicenter studies that could enroll more patients, attention would have to be paid to standardization of criteria and procedures, to be able to meaningfully interpret the sensitivity data obtained from such studies when compared to sensitivity of the reference or index standard.

Panelists also made the point that if CMS and MCAC wanted to refer to diseases as rare that a definition would be needed for the term, possibly through use of incidence rate as well as prevalence. If a distinct set of standards were to be adopted, the Committee suggested considering pretest probability of the disease in question when evaluating “rareness” of the disease. The Committee however, did not come to consensus on a definition of rare disease, nor did they suggest that CMS undertake similar discussions internally. The panel stated they agreed that of the utmost importance in assessing any diagnostic test is whether differences in test performance are important clinically. Said differently, when the test performed results in a definitive diagnosis and is not merely additive, and the diagnosis improves patient outcomes through a change in disease management the Committee would refer to the test as clinically important.

The Chair suggested that diagnostic tests can be assessed for clinical importance by employing simple qualitative disease models in which the first step is to calculate the post-test probability of disease for the reference test as well as the experimental test and comparing those probabilities to find whether the difference between the tests will be important in the management of the patient. Additionally, the Chair recommended reviewing the pre-test probability and post-test probability for both tests in question to assess if the difference between the pre-test probability and post-test probability is enough for either test to make a difference.

Robert Wahl, MD., representing the Academy of Molecular Imaging, made a presentation to the Committee concerning rare cancers and some of the issues that were encountered during his research. Following the presentation, the Committee had some questions for Dr. Wahl, particularly on the use of biological basis to assess the effect of a diagnostic test in rare cancers. Following this questions and answer period, the committee returned to the initial question posed by the Chair regarding modification of the Guidelines to include special instructions for assessing tests that diagnosis diseases that affect small populations. The Committee concluded that the methods for assessing diagnostic tests detailed in the Guidelines are sufficient even for tests that diagnose diseases that affect small populations, and no modifications to the Guidelines are necessary.

Adjournment.   The meeting adjourned at 3:25 p.m.

I certify that I attended the meeting
of the Executive Committee on
September 25, 2002, and that these
minutes accurately reflect what

Janet Anderson
Executive Secretary, MCAC, CMS

I approve the minutes of this meeting
as recorded in this summary.


Harold C. Sox, M.D.