When I first fell down the rabbit hole of Parkinson’s, I was astounded to find out there was no objective test for Parkinson’s Disease (PD). (See Diagnosis blog posting.) There’s no PET scan or blood test that says you have PD; diagnosis is instead based on the neurologist’s observations. So, finding “biomarkers” is the Holy Grail of PD research.
Alzheimer’s Disease (AD) has a similar challenge. Like PD, until recently, Alzheimer’s diagnosis was based on the clinician’s observations and like PD, there was not a definitive diagnosis until an autopsy. However, Alzheimer’s is further along towards the Holy Grail of objective tests. (Presumably the research dollars are larger, since Alzheimer’s currently impacts some 5 million Americans vs. 1 million for Parkinson’s.) New methods are rapidly emerging to diagnose AD, including new brain imaging-based tests; biomarkers detectable in blood, plasma, and cerebrospinal fluid (CSF), and even retinal scans. In April, 2011, for the first time in 27 years, diagnostic criteria for Alzheimer’s disease (AD) were revised by National Institutes of Health and the Alzheimer’s Association to include consideration of biomarker tests.
This is certainly good news for research — scientists can more efficiently identify who has the disease, and can more objectively measure the efficacy of drug trials or other therapy. But there is still no commonly used diagnostic test for routine clinical practice. Insurance companies are wrestling with whether there is sufficient evidence that new diagnostic tools will improve patient outcomes.
The blunt reality is, do you want to spend a lot of money to find out you have an incurable disease?
Insurance companies include Uncle Sam (Medicare and Medicaid). On July 9, 2013, a panel of the Centers for Medicare and Medicaid Services will decide whether the feds will cover a $3000 test that, for the first time, accurately identifies the amyloid brain plaques characteristic of Alzheimer’s. (Check out Elizabeth Lopatto’s 7/1/13 story on Bloomburg News.)
Eli Lilly’s Amyvid imaging agent for PET scans was approved by the US Food and Drug Administration last year, but it is not a definitive test: Sparse or no plaques is “inconsistent” with AD diagnosis (Translation: dodged that bullet), while moderate to frequent plaques, per Amyvid’s prescribing information , “is present in patients with AD, but may also be present in patients with other types of neurologic conditions as well as older people with normal cognition”. Translation: a positive result may mean AD, some other type of dementia, or no dementia.
So, would you want your tax dollars to cover this test? On the pro side, the test provides peace of mind for people who receive negative results, and, for people who receive positive results, efficiently identifies potential early AD patients for research. The test also can help narrow down the appropriate therapy, since there are many causes for dementia. On the con side, adding this test to the (covered) diagnostic tool box serves little purpose: it’s not definitive, and, even if it were, AD is not curable. To use the insurance standard, does it improve patient outcomes?
I used to think medical insurance should be rational and not cover items that cost a lot for very little medical benefit. Now that I have Parkinson’s, I’m all for insurance coverage for any PD biomarker, no matter the cost vs. benefit. Any tool that helps identify people with PD and measures progress of therapies will make research more efficient — that has got to be a good thing.