Interest in and Experience with Genetic Testing for Late-Onset Medical Conditions: Results from the National Poll on Healthy Aging.

Background: The increasing availability of genetic testing for late-onset diseases such as Alzheimer's disease necessitates understanding public perceptions and experiences of such testing among at-risk populations.

Objectives: To assess (a) prior uptake of genetic testing (both in medical and direct-to-consumer settings), (b) future interest in genetic testing for late-onset conditions (e.g., Alzheimer's disease, Parkinson's disease), and (c) perceptions of testing pros and cons among middle-to-older aged adults.

Design: Online, cross-sectional survey study.

Setting: The National Poll on Healthy Aging at the University of Michigan is a recurring biannual survey of a nationally representative sample of adults aged 50-80. This study reports on a March 2018 fielding of the survey that included a genetic testing module administered to adults aged 50-64.

Participants: Study participants were 991 community-dwelling adults aged 50-64.

Measurements: Survey measures assessed (a) prior use of genetic testing, (b) reasons for engaging in genetic testing, (c) interest in different types of genetic testing, including for Alzheimer's disease, Parkinson's disease, and macular degeneration, and (d) perceived benefits, risks, and limitations of testing.

Results: Previous uptake of genetic testing was limited (medical use: 5.1%; direct-to-consumer: 10.8%), with direct-to-consumer test uptake higher among respondents with household incomes of $100,000 or more. Over half of adults endorsed interest in genetic testing for estimation of disease risk (58.9%), ancestry knowledge (58%), and informing medical care (53.8%). Interest in genetic testing for specific late-onset conditions was even higher, including Alzheimer's disease (70%), Parkinson's disease (65.3%), and macular degeneration (64.3%). Multivariable logistic regression models showed that older adults more likely to be interested in genetic testing for medical or disease risk purposes were those with higher levels of education (college degree or higher) and who endorsed the benefits of genetic testing, whereas respondents who endorsed testing risks and limitations were less likely to express interest.

Conclusion: While prior use of genetic testing among the middle-to-older age population was low, interest in testing for Alzheimer's disease and other late-onset conditions was high. This high interest may translate into increased uptake given expanded access to testing and recent treatment advances for Alzheimer's disease.