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A new accurate blood test for Alzheimer’s, or another false call?
2020 was a good year for Alzheimer’s blood tests. Many new tests, all different biomarkers, and all accurately predicting Alzheimer’s. Have you ever wondered how that is possible? How different biomarkers can all accurately predict a disease that is so complex? The answer is short and sobering: they can’t. Too often, the studies behind the tests don’t support the claims.
2021 is only one week old, and researchers have already come up with another blood test. “We can now very accurately predict the risk of developing clinical Alzheimer’s disease in the future, with a simple blood test on symptom-free individuals with subjective concerns,” the press release reports. Unfortunately, this study appears no exception.
I study predictive testing and know that mistakes in prediction studies are common. In my view, these studies are often conducted by researchers who are excellent in their fields but lack expertise in prediction. They don’t recognize the shortcomings in their studies and write about their research as if nothing’s wrong. This press release gave away three such hints.
First and second, the study was small for developing a biomarker test, only 203 patients, and didn’t include an independent group of patients in which the test was tested. For predictive tests, such validation is…
