OBJECTIVES : Genetic testing can provide significant benefits to patients with rare diseases, and there is a need for patients, physicians, and other stakeholders to understand the benefits of genetic tests. This study evaluates the relative importance to patients of the features of genetic tests for rare muscle weakness diseases.

METHODS : We designed an online discrete-choice experiment (DCE) with six test attributes: number of diseases tested for and probability of diagnosis, time until results available, whether treatments exist, whether the test might return unrelated health information, whether a muscle biopsy is required, and the average time until a final diagnosis if the test was negative. Respondents were asked to assume they were experiencing unexplained muscle weakness. A follow-up question presented a choice between two tests with different costs; respondents were randomly assigned to one of two cost ranges. Data were analyzed using random-parameters logit.

RESULTS : The sample includes 600 adults aged 18 to 50 years recruited from the general population through an online panel. Respondents valued faster times to diagnosis and tests for diseases with treatments. Compared with women, men placed relatively more importance on tests for diseases with treatments. A majority of the sample said they would be more willing to get a genetic test that might return unrelated health information, and women had a statistically significant preference for tests that might provide unrelated health information. Respondents were sensitive to cost, but 30% of the sample assigned to the highest cost were willing to pay $500 for a test that provided a diagnosis almost 2 years earlier.

CONCLUSIONS : The results support a desire for faster diagnosis of rare, unexplained muscle weakness and diagnosis of diseases with treatments. Faster diagnosis can provide earlier access to treatment and an end to the diagnostic journey, which patients highly value.