OBJECTIVES: New treatments have been developed for spinal muscular atrophy (SMA), a rare neuromuscular disease. The study’s objective was to estimate disutilities for SMA for use in cost-effectiveness analyses using a stated preference survey.

METHODS: A targeted literature review and expert consultations were used to inform attribute selection, descriptions and levels for a discrete choice experiment (DCE). The following attributes were included: overall survival, motor function, respiratory function, mode of administration, treatment reactions, requirement for eyesight monitoring and need of contraception. The experimental design was informed by an orthogonal fractional factorial array. The survey was administered to a sample of the UK general population aged ≥18 years. Quotas for age, gender and region were set using UK census data to ensure sample representativeness. The random parameter logit model estimated strength of preference for the attributes. Marginal rates of substitution were estimated between survival and other attributes in order to estimate disutilities, weighted against average life expectancy.

RESULTS: 506 participants were included in the analysis. Model results indicated that participants valued improved motor function most, followed by increased life expectancy and improved respiratory function. Participants made choices to avoid intrathecal injections, treatment reactions, and ophthalmologic monitoring. Estimated disutilities were largest for not being able to sit compared with walking independently (–0.408) and for >16 hours mechanical breathing support versus no support (–0.304). Estimated disutilities for oral versus intrathecal treatments (–0.071), 3–4 days of treatment reactions versus no reactions (–0.087), ophthalmologic monitoring twice a year versus no monitoring (–0.023) and need for contraception versus no need for contraception (–0.012) were smaller.

CONCLUSIONS: This study demonstrated the value that the general population places on treatment attributes for SMA, using a method for estimating disutilities for economic modeling that may be particularly suited to rare disease indications.