This longitudinal mixed methods study aimed to assess the perceived effect of salbutamol in adult patients with spinal muscular atrophy (SMA) and to evaluate the usefulness of WHO Disability Assessment Schedule II (WHODAS-II) and Fatigue Severity Scale (FSS) to measure it. Ten patients were interviewed and filled in WHODAS-II and FSS questionnaires to assess disability and fatigue at 2 time points. Inductive thematic analysis was used for qualitative data. The non-parametric Wilcoxon test was performed for quantitative analysis. All participants reported an improvement in their condition after salbutamol consumption. WHODAS-II and FSS captured changes in patients’ disability and fatigue reliably. The mixed methods design allowed us to identify the functional domains in which participants experienced effects of salbutamol. Because of decreased fatigue, improved functioning, and few side effects they were satisfied with the treatment.
