The New Diagnostic Scan for Alzheimer’s Disease

[Ed. Note: We’re happy to announce that after a great month of guest blogging, Chris Robertson will be joining Bill of Health as a regular contributor.]

By Christopher Robertson

The New York Times brings us an interesting story about a new brain scan technology that allows the diagnosis of Alzheimer’s Disease.  Below the fold, I sketch a few interesting themes for health law, including the FDA’s authority over the practice of medicine, the use of blinding to improve clinical decision making, the value of a clinical diagnosis for an untreatable condition, and the problems of pre-existing conditions clauses in long-term care insurance.

First, the FDA has required that doctors using the scan for diagnosis to pass objective tests of their proficiency in doing so. This is interesting in the light of the old-fashioned idea that the regulation of the practice of medicine is exclusively the business of the states, a principle reflected in 21 U.S.C. § 396, which says that “nothing in this [Act] shall be construed to limit or interfere with the authority of a health care practitioner to prescribe or administer any legally marketed device to a patient for any condition or disease within a legitimate health care practitioner-patient relationship.”  Presumably, Eli Lilly, the maker of the marker used in the brain scans, did not object to this provision, but it is unclear (to me) how the rule could be enforced against physicians who use the procedure “off-label.”  Perhaps the rule just somehow keeps the marker from getting into their hands, by regulating Eli Lilly’s sales and marketing practices?

Second, it is interesting that “the F.D.A. requires that radiologists not be told anything about the patient,” because such clinical information may actually undermine the quality of their diagnoses.  Sometimes ignorance improves decisions, a theme that I have exploited in my own work (see here and here), and which will be the topic of a symposium I am chairing with Aaron Kesselheim at the Edmond J. Safra Center at Harvard next year.  (The call for proposals will be out shortly.)

Third, the NYT article mentions that for patients who receive a positive test diagnostic of Alzheimers, there is often no treatment available.  This reminds me of the current state of the art with regard to whole-genome screening, which will reveal all sorts of genetic abnormalities, many of which are untreatable as of today.  In both cases, it is thus understandable that insurers, including Medicare, are reticent to pay for such a test.  Nonetheless, such tests can be clinically useful if they bring a stop to the “diagnostic odyssey” (see e.g., Farrell 2008) of intrusive tests.  To the extent that that odyssey is expensive, insurers may find it in their rational self-interests to pay for such tests.  And, then of course, there is the argument that information may have intrinsic value to patients.

Fourth, the NYT mentions repeatedly that people are hesitant to undergo the brain scan for fear that the diagnosis will undermine their chances of getting long-term care insurance.  It is interesting that the Affordable Care Act addressed the pre-existing condition problem in health insurance, but left long-term care insurance untouched on this issue.  Long ago, Mark Pauly explained why it is rational for many people to forgo long-term care insurance, and there is a huge adverse selection problem here.  Since Medicaid remains the insurer of last resort especially in this area, the insurers’ cream-skimming imposes a huge burden on the state and federal governments, perhaps worse than the uncompensated care problem for regular health insurance.  Yet, so far, this domain has received much less attention from scholars and policymakers.  More to the point of this article, however, I’m worried about the patients who are thinking about this brainscan in the light of long-term care insurance.   My impression (with some support) is that, “A long term care insurance policy usually defines a pre-existing condition as one for which you received medical advice or treatment or had symptoms within a certain period before you applied for the policy.”   Thus, if the patient has symptoms and is even discussing them with a physician, she may already have a pre-existing condition problem, regardless of whether the brain scan is taken and yields a positive diagnosis.

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