Non-adherence to interferon-beta therapy in Swedish patients with multiple sclerosis

Objectives - To explore the occurrence and reasons for stopping, switching or continuing first prescribed interferon-beta therapy in patients with multiple sclerosis in Sweden, with respect to demographic, clinical and/or therapy-related factors. Materials and methods - A retrospective study reviewing the medical charts of 259 patients with multiple sclerosis, comparing patients continuing therapy for at least 3 years with those switching or stopping therapy. Results - Sixty 9% stopped (15%), or switched (54%), interferon-beta therapy within 3 years. Stoppers had longer disease duration before starting therapy (P = 0.002), less frequently relapsing-remitting multiple sclerosis (P = 0.046), and more often Expanded Disability Status Scale scores 6-9.5 (P = 0.045) compared to Switchers. The most common reasons for switching/stopping therapy were perceived lack of effect and side-effects. Conclusions - Adherence to initial immune-modulating therapy is low; identification of patients at higher risk of stopping therapy and provision of adequate support are essential.