Caregiver Preferences for the Treatment of Males with Fragile X Syndrome.

OBJECTIVE:Fragile X syndrome (FXS) is the most common inherited form of intellectual disability. The objective of this study was to determine the relative importance that caregivers place on improving different phenotypic traits observed in males with FXS to better understand the greatest medical needs for developing and evaluating FXS treatments. METHOD:Fragile X syndrome caregivers (n = 614) compared hypothetical treatments in a discrete-choice experiment. The treatments varied in their effects on 6 outcomes associated with FXS: learning and applying new skills, explaining needs, controlling behavior, taking part in new social activities, caring for oneself, and paying attention. The relative importance was calculated for improving severe or moderate levels of disability and transformed to a 10-point scale. Relative importance was also quantified by patient age group (child, adolescent, and adult). RESULTS:Most important to caregivers were controlling behavior (10.0) and caring for oneself (9.9). Least important was taking part in new social activities (4.2). A partial improvement in controlling behavior or self-care was more important than full resolution of the least important disabilities. This was consistent across age groups. Improvements from severe to moderate disability were more important than from moderate to no disability. CONCLUSION:Caregivers expressed strong preferences for improvement in self-care and behavioral control, independent of the age of the individual with FXS. These data may be helpful when designing studies to test the efficacy of FXS treatments because small treatment effects on very important outcomes may be valued more than large treatment effects on less valued outcomes.