Introduction: In patients with multiple sclerosis (MS), fatigue, depression, and physical disability are important determinants that negatively affect health-related quality of life (HRQoL). In studies about MS, HRQoL and treatment satisfaction are emerging endpoints representing the patients' perspective. However, the association of HRQoL and MS treatment satisfaction has not been evaluated so far.

Purpose: Our objective was to evaluate the relationship of different dimensions of HRQoL and treatment satisfaction (effectiveness, side effects, convenience), and to assess which factors of treatment satisfaction, besides disease-related and sociodemographic explanatory factors, can best describe HRQoL.

Patients and Methods: We analyzed data from a cross-sectional, observational multicenter study in Germany (THEPA-MS, N=2990 eligible patients for first-line treatment). The instruments used were the SF-36 for HRQoL and the TSQM for treatment satisfaction. Correlation analyses, classification and regression trees and multivariate linear regression with the least absolute shrinkage and selection operator (LASSO) for global variable selection were used to analyze explanatory factors of HRQoL.

Results: The SF-36 physical summary score was 45.49 ±12.03 and mental component summary score 42.87 ±12.12, with currently untreated patients (N=250) reporting lower HRQoL than patients under first-line treatment (N=2740) (p<0.001). Physical disability (standardized beta (b)=0.408) was the strongest cross-sectional predictor for physical health, followed by employment status (b=0.163), age (b=0.159) and treatment satisfaction in terms of side effects (b=0.146) and effectiveness (b=0.137). For the mental summary health dimension, presence of a major depressive episode (b=0.234) had the greatest impact, followed by satisfaction with side effects (b=0.152) and effectiveness (b=0.131).

Conclusion: Satisfaction with the effectiveness and side effects of treatment was part of the main independent explanatory variables for mental and physical HRQoL in patients with MS. To improve HRQoL, patients' needs and satisfaction measures may be integral part of disease management beyond treatment of physical disability, depression or fatigue.