Influence of Interferon beta treatment on quality of life in multiple sclerosis patients

Background: Interferon-beta (IFN-beta) shows beneficial effect on the course of multiple sclerosis ( MS), nevertheless its route and frequency of administration and side effects might impact negatively the quality of life (QoL) of MS patients. The objective of this study was to evaluate the influence of IFN-beta on QoL in MS patients. Methods: Seventy-seven disease modifying treatment (DMT) free and 41 IFN-beta treated MS patients were evaluated. QoL, assessed by MSQoL-54, was related to IFN-beta treatment and to clinical and demographic parameters at baseline and after two years. Multivariate hierarchical linear model for repeated measurements was used. Results: Treated patients showed a younger age, a lower disease duration and a higher relapse rate in the two years preceding study entry. At inclusion time treated and untreated patients did not differ in relapse rate, expanded disability status scale (EDSS), fatigue, depression, physical and mental QoL. IFN-beta did not influence QoL at inclusion time, but when QoL was evaluated after two years, treatment negatively affected mental QoL. Depression and fatigue negatively influenced physical and mental QoL both at baseline and after two years. EDSS correlated with a poor physical QoL only at baseline. Conclusion: IFN-beta had a negative impact on QoL over the time in MS patients, influencing mainly mental QoL. The impairment of QoL in MS was strongly associated with increasing fatigue and depression, whereas clinical disability had a minor unfavourable role.