Monday, July 24, 2023

AI Corner: AI Assesses, Discusses, CMS Decision to End NCD for Amyloid PET scans.



Chat GPT-3.5 reads and discusses the July 17 CMS proposal to end  NCD-controlled coverage of Amyloid PET scans, and leave this up to MACs.  As always with AI examples, I'm not framing the AI essay as good or bad, but as a work product that might be of interest. 

Not only do we ask ChatGPT to assess the proposed NCD, which would result in the NCD removing itself (reflexive!).  As a final request, we also ask ChatGPT to write an association's letter, asking CMS to keep the NCD in place and not recind it (at bottom). 

Find the proposed decision memo here.

Find my original July 17 blog here.

 Summary of CMS Decision on Amyloid PET Scans:

Chat GPT-3.5

CMS conducted a reconsideration of the national coverage determination (NCD) for beta amyloid PET scans in dementia and neurodegenerative disease. The decision-making process involved a thorough review of evidence, including peer-reviewed literature, external technology assessments, internal technology assessment, and public comments.

Evidence Review:

Peer-Reviewed Literature: CMS reviewed published medical literature, clinical trials, and major studies related to interventions guided by PET Aꞵ imaging to improve health outcomes for patients, including Medicare beneficiaries.

External Technology Assessments: No external technology assessment was requested by CMS on this issue.

Internal Technology Assessment: The literature search was extensive and included databases like Academic Search Premier, CINAHL, Google Scholar, PubMed, Scopus, and more. Reports from various agencies were also considered.

Public Comments: CMS considered public comments received during the 30-day comment period, focusing on the question of whether to remove the current NCD for beta amyloid PET scans.

Decision Justification:

Based on the evidence and stakeholder feedback, CMS determined that the current NCD for beta amyloid PET imaging (NCD 220.6.20) should be revoked, ending the Coverage with Evidence Development (CED) requirement. The decision was justified by several factors:

  • Advances in Medical Care: Since the establishment of the NCD in 2013, there have been significant advances in medical care, including the development of antiamyloid drug treatments. The use of amyloid PET scans has evolved, and now they are used to confirm the presence of brain amyloid to select appropriate patients for these treatments.
  • Individualized Patient Treatment: Patient factors, such as medical comorbidities, concomitant medications, and individual response to treatments, need to be considered when using amyloid PET scans for treatment decisions.
  • Local MAC Discretion: Removing the NCD would allow local Medicare Administrative Contractors (MACs) to make coverage determinations, including covering more than one scan per patient's lifetime and use within or outside the context of a CMS approved study. This would provide flexibility in response to new evidence and developments in medical care.
  • Health Disparities: CMS acknowledges significant disparities in the prevalence of Alzheimer's disease (AD) across racial and ethnic groups. Revoking the NCD may help improve access to amyloid PET scans for underrepresented populations and support better healthcare for all individuals.

In conclusion, CMS has proposed to remove the NCD for beta amyloid PET scans, allowing MACs to make coverage determinations based on individual patient needs and current medical knowledge. The decision reflects the evolving landscape of medical care and the importance of personalized treatment for patients with dementia and neurodegenerative diseases.

In the past, in some CMS decisions like this one, the text rambled and covered miscellaneous topics without clear rationale for their inclusion or relevance to the final decision. Does CMS's discussion here, seem well focused on the purpose of the decision?   The decision was relatively short (14pp not 50 or 70).


Yes, the discussion in this CMS decision appears to be well-focused on the purpose of the decision. The text is relatively concise (14 pages) compared to some previous decisions, which suggests that CMS has made an effort to present the relevant information without unnecessary rambling or inclusion of miscellaneous topics.

The decision starts by providing background information on the NCD reconsideration and the evidence review process. It then proceeds to discuss the key questions addressed in the reconsideration, specifically focusing on whether to revise the current policy or remove the NCD for beta amyloid PET scans. Throughout the discussion, CMS clearly explains the evidence considered, including the peer-reviewed literature, technology assessments, and public comments.

The justification for revoking the NCD is laid out in a clear and logical manner, emphasizing advances in medical care, the importance of individualized patient treatment, and the potential to address health disparities. The decision also highlights the role of local MAC discretion in making coverage determinations, providing flexibility and responsiveness to evolving evidence.

Overall, the text appears to be well-organized and focused on the central purpose of the decision, making it more concise and accessible for expert readers in the field of national health policy.

What criticisms of the NCD might a policy expert have?


A policy expert might have several criticisms of the NCD for beta amyloid PET scans:

Lack of Clarity in Decision-Making: The decision-making process in the NCD may not be entirely transparent, and some aspects of the evidence review and rationale for certain conclusions may not be clearly explained. This lack of clarity can lead to confusion and raise concerns about the validity of the decision.

Inadequate Consideration of Cost-Effectiveness: The NCD may not adequately consider the cost-effectiveness of beta amyloid PET scans, which can be an essential factor in determining whether a medical intervention should be covered by Medicare. Cost-effectiveness analysis is crucial in ensuring the efficient allocation of healthcare resources.

Limited Patient Access: The once-in-a-lifetime limit for PET amyloid scans may restrict patient access to potentially beneficial diagnostic tests. Some experts might argue that this limit should be re-evaluated, especially in light of advances in medical care and the need for individualized treatment approaches.

Inconsistencies with Other CMS Decisions: The NCD might be inconsistent with other CMS decisions or coverage policies, leading to potential disparities in coverage and treatment options for patients with similar conditions. Ensuring consistency across decisions is essential for fair and equitable healthcare coverage.

Addressing Health Disparities: While the NCD mentions health disparities, some experts may argue that it does not go far enough in addressing these disparities. More specific strategies and interventions may be needed to ensure equitable access to diagnostic tests and treatments for underrepresented populations.

Limited Engagement with Stakeholders: Policy experts may criticize the NCD for not fully engaging with all relevant stakeholders, including patient advocacy groups, healthcare providers, and researchers. Involving stakeholders in the decision-making process can lead to more informed and comprehensive policy outcomes.

Scope of Evidence Review: Some experts may question whether the evidence review process considered all relevant studies and data, including potential biases or conflicts of interest in the research presented. Ensuring a comprehensive and unbiased evidence review is crucial for making well-informed policy decisions.

Flexibility and Adaptability: The NCD might be criticized for not being flexible enough to adapt to future developments in medical research and technology. As medical knowledge evolves, policies must remain adaptable to incorporate new evidence and treatment options.

Overall, these criticisms reflect the complexity of making national coverage decisions and the need for continuous improvement and refinement of healthcare policies to best serve patients' interests and promote equitable access to high-quality care.

Based on the CMS discussion, does it foresee or consider any drawbacks to leaving the Amyloid PET decisions in the hands of local contractors?


Based on the CMS discussion provided, there doesn't appear to be any explicit mention of drawbacks to leaving the Amyloid PET decisions in the hands of local contractors (MACs - Medicare Administrative Contractors). The discussion primarily focuses on the advancements in medical care, the development of new treatments for Alzheimer's disease targeting amyloid, and the need to confirm the presence of brain amyloid using PET scans for appropriate patient selection in treatment trials.

The CMS decision proposes to remove the National Coverage Determination (NCD) for beta amyloid PET in dementia and neurodegenerative disease, which would allow local MACs to make coverage determinations regarding the use of PET beta amyloid imaging. The justification provided is that the advances in medical care, standards of practice, and development of proven treatments have altered the application of amyloid PET scans in clinical practice and research. CMS believes that the local MACs can promptly respond to the evidence on proven treatments for individual patients.

While the discussion doesn't explicitly mention drawbacks to leaving the decisions to local contractors, there are potential concerns that could be raised by policy experts:

Inconsistent Coverage: Different MACs might interpret evidence differently, leading to inconsistent coverage decisions across different regions. This could create disparities in patient access to PET beta amyloid imaging and related treatments.

Variable Expertise: Local contractors might not have the same level of expertise or resources to conduct comprehensive evidence reviews and make well-informed coverage decisions, potentially leading to variations in the quality of decision-making.

Burden on Providers: Providers may face administrative burdens in navigating different coverage policies across different regions, leading to additional paperwork and administrative complexities.

Health Disparities: Leaving the decision to local contractors may not fully address health disparities, as certain regions or populations might still face barriers to access amyloid PET scans, leading to potential inequities in healthcare.

It's important to note that while these potential drawbacks are not explicitly discussed in the CMS decision, they are considerations that policy experts might raise when evaluating the proposal to leave the coverage decisions to local contractors. Policymakers need to carefully assess the potential trade-offs and implications of such a decision to ensure equitable access to healthcare services for all beneficiaries.

In that answer, you noted that CMS elaborated on no drawbacks.  However, you chose to add, there ARE potential drawbacks that an expert might have raised.  That was very helpful to add that extra part to your answer.


Thank you for your feedback, and I'm glad you found the additional information helpful. As an AI language model, my aim is to provide comprehensive and insightful responses to your questions. While the CMS discussion may not have explicitly mentioned drawbacks, it's essential to consider potential concerns that policy experts might raise when evaluating such decisions. Including those points can help provide a more well-rounded perspective on the topic. If you have any more questions or need further assistance, feel free to ask!

A stakeholder association wants to write CMS a comment letter opposing the decision and preferring to keep the status quot (under the status quo, amyloid PET is available only in pre-approved clinical trials or registries.)  Please draft such a letter to CMS.   


[Your Association's Letterhead]


Centers for Medicare & Medicaid Services (CMS)

Department of Health and Human Services

Attention: CMS-1753-P

P.O. Box 8016

Baltimore, MD 21244-8016

Subject: Comments on Proposed Decision CMS-1753-P - Amyloid PET Imaging Coverage Determination

Dear Administrator,

[Association Name] is writing to express our strong opposition to the proposed decision (CMS-1753-P) to remove the National Coverage Determination (NCD) for Amyloid PET Imaging (NCD 220.6.20) and to leave coverage determinations to local Medicare Administrative Contractors (MACs). As a stakeholder association representing [state the stakeholders you represent, e.g., patients, caregivers, healthcare providers, etc.], we firmly believe that retaining the status quo, where amyloid PET is available only in pre-approved clinical trials or registries, is in the best interest of Medicare beneficiaries and the healthcare system as a whole.

We acknowledge that CMS has conducted a thorough review of the evidence surrounding amyloid PET imaging and its potential benefits in diagnosing and treating dementia and neurodegenerative diseases. However, we respectfully disagree with the decision to revoke the NCD and here's why:

Lack of Consistency and Access Disparities: Allowing local MACs to make coverage determinations could lead to disparities in access to amyloid PET imaging services across different regions. Inconsistent coverage policies may create confusion for healthcare providers and patients, potentially resulting in delayed or denied access to essential diagnostic tests.

Increased Administrative Burden: The proposed decision to decentralize coverage determinations places an additional administrative burden on both healthcare providers and Medicare beneficiaries. Local MACs may have varying criteria and requirements for coverage, leading to increased paperwork and complexities in the reimbursement process.

Implications for Vulnerable Populations: Disadvantaged and underserved populations may face even greater challenges in obtaining access to amyloid PET imaging under a decentralized coverage system. Racial and ethnic minorities, who are already disproportionately affected by Alzheimer's disease, may face further barriers in obtaining timely and accurate diagnoses.

Potential Conflicts of Interest: Local MACs may face financial pressures and other interests that could influence their coverage decisions. This situation could potentially compromise the objectivity and impartiality of coverage determinations, leading to decisions that prioritize cost-saving measures over patient care.

Uncertain Impact on Clinical Research: The proposed decision may inadvertently deter clinical research in the field of amyloid PET imaging. If local MACs restrict access to amyloid PET scans, researchers may face difficulties in enrolling participants for clinical trials, hindering the advancement of scientific knowledge in this critical area.

Given these concerns, we strongly urge CMS to reconsider the decision and maintain the current NCD (220.6.20) for amyloid PET imaging. By continuing to limit coverage to pre-approved clinical trials and registries, Medicare beneficiaries will have equitable access to this important diagnostic tool, and healthcare providers will be able to make informed treatment decisions based on reliable and standardized criteria.

Furthermore, we recommend that CMS collaborate with stakeholders, including patient advocacy groups, healthcare professionals, and researchers, to develop evidence-based coverage policies that promote equitable access, clinical utility, and patient-centered care.

Thank you for considering our comments on this critical issue. We look forward to continued collaboration and constructive dialogue to ensure the best possible outcomes for Medicare beneficiaries and the healthcare community.


[Your Name]

[Your Title/Position]

[Association Name]

[Contact Information: Address, Phone, Email]