Treatment preferences in spinal muscular atrophy: A swing weighting study for caregivers of patients with SMA types 1 and 2

Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder characterized by skeletal muscle weakness and atrophy. Patients with SMA types 1 and 2 develop severe disabilities conferring substantial patient and caregiver burden. Caregiver treatment characteristic preferences are useful for informing treatment choices and improving adherence. We aimed to identify drivers of SMA treatment preference from the perspective of caregivers of patients with SMA types 1 or 2 in the United States. We quantified the relative importance of different treatment characteristics and compared preferences for hypothetical treatment scenarios. Treatment attributes and attribute levels elicited were based on a literature search and interviews with caregivers and health care professionals. The most important treatment characteristics from the perspective of health care professionals and caregivers were identified and used in a survey to quantify relative importance for caregivers. Caregivers completed surveys regarding their preferences using swing weighting methodology. These results were used to estimate the relative value of four hypothetical SMA treatment scenarios exploring different modes of treatment administration. The swing weighting survey, completed by 20 caregivers, demonstrated that the attributes driving treatment preference were reduction in permanent ventilation needs and risk of severe adverse events, followed by treatment access (including cost coverage and availability), increased ability to sit without support, and less treatment administration burden. The hypothetical SMA treatment scenarios with the highest relative value offered an easier mode of administration, lowest risk of severe adverse events, less need of permanent ventilation, and highest ability of patients to feed and sit without support. Our findings suggest that caregivers prefer a treatment with reduced clinical burden and risk in which the cost is covered and treatment is available in the short term. These results can provide important contextual information for decision-makers and help promote patient-centered care for patients with SMA.