Value of Knowing the Risk of Developing a Neurodegenerative Disease: A Discrete Choice Experiment

Genetic tests predict an individual's risk of developing neurodegenerative diseases. A portion of the value provided by genetic tests can be attributed to the individual's value of early knowledge of their risk, or the "value of knowing."

We developed a discrete choice experiment survey and administered it to a nationally representative sample of US adults. Respondents were presented with 8 choice tasks, each with two hypothetical tests and an opt-out option, where tests varied in cost, type, and accuracy. Respondents were randomly assigned to scenarios with varied disease severity, perceived risk, treatment availability, and whom the test was for. We used a generalized multinomial logit model to estimate preferences and willingness to pay (WTP).

The final sample included 1,034 respondents. The alternative-specific constant implied a baseline model-derived WTP of $2,954 (95% CI: $$2,559, $3,348) for undergoing genetic testing. Estimates were higher when the disease being tested for was fatal, when perceived disease risk was high, and when considering testing for a child. Conversely, preferences were lower for low-severity diseases and when considering testing for oneself. In exploratory subgroup analyses, respondents with genetic testing experience, those who had children, and those who had cared for someone with a neurodegenerative disease reported a higher marginal WTP.

Our study suggests that individuals place a premium on knowing their risk of developing a neurodegenerative disease. These findings provide preference evidence that may inform coverage deliberations for genetic tests for neurodegenerative disease when considered alongside other decision criteria.