This used to be a purely academic question: If you could know, years before you had symptoms of Alzheimer’s disease, that you were likely to develop it–and there was no treatment or cure–would you want this information? Now it is a real dilemma because there are brain scans and other biomarker tests to detect very early signs of Alzheimer’s disease, leading to recognition of preclinical stages of the disease, and yet there are still no interventions.
A new survey of researchers investigating the validity of such tests finds strong support for disclosing the results to participants, and a desire for guidance on how to do this responsibly.
The survey included 159 investigators in the Alzheimer’s Disease Neuroimaging Initiative (ADNI), a longitudinal study that has been evaluating the use of biomarker tests to identify signs of Alzheimer’s disease in people whose memories are normal, as well as those with mild cognitive impairment (often a precursor to Alzheimer’s disease), and those with Alzheimer’s disease. The ADNI study has had a policy that researchers will not disclose individual research results to participants.
The survey asked the investigators if they would support the return of results of a brain imaging test if it received approval from the Food and Drug Administration and, therefore, could be used as a diagnostic tool for patients with memory problems. The test, which was under review by the FDA when the survey was conducted, estimates the density of amyloid plaque, a protein that forms in the brains of people with Alzheimer’s disease and some other cognitive disorders.
Fifty-eight percent of respondents said they would support returning the results of the brain imaging test to participants with normal cognition, and 73 percent supported disclosing the results to participants with mild cognitive impairment. Of the 139 respondents who had direct contact with study participants, more than half said that participants with normal cognition or mild cognitive impairment had requested their results.
What began as a “what if” survey took on real-world relevance when the FDA approved the brain imaging test for amyloid plaque in April 2012, shortly after the survey was completed. If patients concerned about their memory could now get the imaging test in their doctor’s office and learn whether they had biomarkers of Alzheimer’s disease, why shouldn’t research participants also have access to that information?
Respondents who favored returning results to research participants appealed to the ethical arguments to respect their autonomy and “right to know,” instead of researchers “paternalistically withholding information from participants.” Some respondents argued for disclosing results only to participants who asked for them, citing their right not to know.
Despite the strong support for returning results, the respondents wanted evidence-based guidelines on how to do this, including investigations on the value and impact of disclosure of biomarker information on research participants and clinical practice recommendations. “The survey showed that these investigators recognize that the study of AD is experiencing tremendous flux,” the report says.
An accompanying editorial envisions the possibility that demand for amyloid imaging in the U.S. will be driven not by clinicians but by patients, especially with the population aging and the free reign of direct-to-consumer advertising. “Ethical issues raised by biomarker positivity in asymptomatic individuals can be considered generic to the field, as we need some societal consensus beyond individual study policies,” the editorial states. That can be read as a call to arms for bioethics.
Susan Gilbert is the public affairs and communications manager of The Hastings Center.