Therapy adherence to immunomodulator treatment in patients with multiple sclerosis

Immunomodulator treatment modifies the course of the disease in patients with multiple sclerosis. The patient's adequate adherence with the treatment regimen is absolutely essential. To determine the real adherence with first-line immunomodulator treatment and to try to find out what factors may influence adequate adherence with the treatment. We conducted an observation-based, retrospective, longitudinal study of the patients being followed up by the Centre d'Esclerosi Multiple de Catalunya at the Hospital Universitari Vall d'Hebron that were given first-line immunomodulator treatment (interferons or glatiramer acetate) between 1st January 2010 and 30th September 2011. Adherence was measured using the medication possession ratio (MPR): patients with an MPR above or equal to 80% were considered to be compliers. We studied 975 patients. The mean time of exposure to immunomodulators over the collected period was 13.4 ± 7.1 years. Altogether 85.2% of patients complied with the immunomodulator treatment adequately. Of a total of 975 patients treated, 134 needed to change to a second drug and 12 patients had to go on to a third. Changing the medication improved adherence (p = 0.001). The annual rate of attacks was 0.23. Only the presence of attacks (p = 0.029) and the drug used (p = 0.044) had any influence on treatment adherence, on an individual basis. The percentage of patients with adequate treatment adherence in our centre is high. The rate of attacks and the drug used play a decisive role. Close monitoring and personalised counselling are required to maintain good therapeutic adherence.