OBJECTIVES: Spinal muscular atrophy (SMA) is a rare, genetic neuromuscular disease. The study objective was to evaluate patient and caregiver preferences for treatment attributes in Type 2 and non-ambulatory Type 3 SMA across five European countries using a stated preference survey.

METHODS: A total of sixty-five adult patients (n=42) and caregivers of patients (n=23) with Type 2 and non-ambulatory Type 3 SMA from Portugal (n=18), the Netherlands (n=17), Finland (n=12), Ireland (n=11) and Belgium (n=7) were recruited via patient associations to take part in an online discrete choice experiment (DCE) survey. Participants completed a survey version in their local language.

Attribute selection and attribute descriptions were based on an earlier DCE study and updated using recent literature on SMA treatments. Five attributes, each with 3 attribute levels, were included: motor function, breathing function, treatment administration, treatment risks and side effects (diarrhoea and rash risk vs. fever, headache, vomiting and/or body pain vs. liver injury risk with fatigue, headache and nausea), and treatment evidence in different SMA populations. A conditional logit model with clustering by respondent was used to estimate strength of preference for each attribute.

RESULTS: The model results indicated that participants placed most value on motor function, followed by breathing function. Participants also made choices to avoid intrathecal injections, liver injury risk with fatigue, headache and nausea, and treatments with evidence in Type 1 SMA only (i.e. no demonstrated effectiveness in Type 2 or 3 SMA).

CONCLUSIONS: Patients and caregivers of patients with Type 2 and non-ambulatory Type 3 SMA place great value on motor function, followed by breathing function. The study results show the considerable value of improvement as well as stabilisation of function to patient and caregivers. The pooled study data from five small- and medium-sized European countries could inform national decision making in this rare disease.