OBJECTIVES: SMA (spinal muscular atrophy) is a rare genetic disorder characterized by the progressive systemic degeneration of muscle tissues, leading to gradually worsening muscle atrophy symptoms. The purpose of this study is to create an HRQoL (Health-Related Quality of Life) for SMA, based on patients who have a thorough understanding of the condition, prior to developing vignettes related to health status that will be administered to the general population in future research.

METHODS: Five vignettes, developed through prior research and clinical consultations, were categorized based on the increasing severity of the disease, considering the use of respiratory assistance and the level of mobility(sitting, standing, and walking with assistance). The final vignette was employed to generate weights for HRQoL using the EQ-5D-5L/EQ-5D-Y self and/or proxy-reported version. The ultimate vignette was conducted in face-to-face sessions with SMA patients who visited Gangnam Severance Hospital in Seoul from March 21 to November 20, 2023.

RESULTS: A total of 36 final SMA patients responded to the survey, with a median age of 22 years (IQR 13.8-29.3). The Utilities for each disease progression state were as follows: 'Inability to sit and requires permanent respirator' (0.022), 'Inability to sit and requires breathing support' (0.132), 'Able to sit with support' (0.411), 'able to stand with assistance' (0.685), and 'able to stand and walk without assistance' (0.911). Sensitivity to disease progression was observed in the domains of mobility, self-care, usual activity, anxiety/depression, and pain/discomfort.

CONCLUSIONS: This study generated utilities through five health status vignettes explaining the disease progression in SMA patients. It was found that as the severity of SMA worsened, the quality of life significantly decreased, impacting HRQoL in all domains.