EQ-5D and SF-6D health utility scores in patients with spinal and bulbar muscular atrophy

Objective This study assessed patient-reported health-related quality of life (HRQoL) using two generic preference-based measures in Chinese patients with spinal and bulbar muscular atrophy (SBMA) and identified demographic and clinical determinants of health utility scores in this population. Methods This study used cross-sectional data of 212 Chinese patients with SBMA who completed both the EQ-5D and SF-6D. Association between response to EQ-5D and SF-6D dimensions was examined using Spearman's correlation coefficient, and the association between the two utility scores was assessed using Pearson's correlation coefficient. The variations in utility scores across patients in different subgroups were compared using one-way ANOVA. Bland-Altman (B-A) plot was used to assess the agreement of utility scores between EQ-5D and SF-6D. A multivariate Tobit regression model was employed to estimate the association between utility scores and the presence of symptoms and chronic conditions. Results The mean utility scores for the EQ-5D and SF-6D were 0.54 and 0.56, respectively. The hypothesized correlation between the EQ-5D and SF-6D dimensions ranged from 0.31 to 0.58, and the correlation between their utility scores was 0.64. An acceptable agreement between EQ-5D and SF-6D utility scores was identified by B-A plot. Patients with chronic diseases, misdiagnosis, high financial burden, and several clinical symptoms were highly likely to report a low health utility score. Conclusions This study is the first to investigate the HRQoL of patients with SBMA worldwide. The estimated health utility scores for EQ-5D and SF-6D can be utilized as baseline data for future cost-utility analyses of SBMA-related interventions.