Research volunteers often do not want to find out their risk of developing Alzheimer’s disease when given the opportunity to do so from biomarker tests, a study has revealed.
The findings, published in JAMA Network Open, reveal the quandary people face when offered the opportunity to discover their risk of this common form of dementia, which currently has no cure.
The study showed a large discrepancy between people who said they theoretically would like to find out about their risk and the proportion who decided to when the prospect actually materialized.
Indeed, 40% declined to find out when given the opportunity, with the most common reason being the burden this knowledge would entail.
“In general, there is movement toward giving research participants and patients their test results, even in situations when nothing can be done with those results,” said senior investigator Jessica Mozersky, PhD, an assistant professor of medicine at the Bioethics Research Center at Washington University Medical Center.
“But our study suggests that in sensitive cases—such as when estimating the risk of developing a debilitating and deadly disease—people should have the option to not know.”
The findings come from research participants in a longitudinal study of aging and dementia who were offered research results as part of a secondary study.
Participants who were aged 65 years or over and cognitively unimpaired underwent genetic tests, brain scans, and had blood samples drawn to estimate their probability of developing Alzheimer’s disease over the next five years.
This included apolipoprotein E genotype, imaging with amyloid positron emission tomography and magnetic resonance imaging, and plasma amyloid level.
They had joined the original study with the understanding that they would not receive their own risk results, although Mozersky said that over the years, many had expressed theoretical interest in their results.
A subgroup of 274 participants was then offered results to examine the psychological impact of this and the factors involved in decision making.
While 81% of people in the larger cohort said they would choose to know, when they were given the opportunity, just 60% of the 274 participants opted to receive them when the offer was made.
Those who self-identified as Black or had a parent with Alzheimer’s disease were more likely to decline. Black participants had an adjusted risk ratio of 1.89 for declining research results after adjusting for potential confounding factors, while this figure for those with a parental history of Alzheimer’s disease was 1.49.
Qualitative interviews suggested that a family history of the disease may create negative experiences and perceptions of the disease, which may influence the decision to learn results.
“The lack of preventive treatments is also a big factor in declining to receive the results of biomarker tests among people without symptoms of Alzheimer’s disease dementia,” explained Mozersky.
“When we conducted interviews with some participants to better understand their choice not to know, many said that a new effective treatment might change their mind, if it became available.”
