Abstract
Background Despite the apparent benefits of disease-modifying drug (DMD) use among multiple sclerosis (MS) patients, their rates of adherence are often variable and in some cases are quite low. Aim of the study To assess medication adherence and its relationship with treatment satisfaction of MS patients in Saudi Arabia Patients and methods Following a cross-sectional design, 598 adult MS patients were recruited from all tertiary care hospitals in all regions of Saudi Arabia. Patients' medication adherence was assessed using the Arabic version of the eight-item Morisky Medication Adherence Scale (MMAS-8). Treatment satisfaction was assessed using the Treatment Satisfaction Questionnaire for Medication. Disease severity was assessed using the Patient-Determined Disease Steps (PDDS). Results The most used drug was interferon beta-1b (24.1%), while 18.7% were using interferon beta-1a and 17.4% were using fingolimod. Patients' mean PDDS was 2.8 +/- 1.9. Only 9.7% were "adherent" to medication. Patients' adherence differed according to their educational level (p < 0.001), their currently received medications (p = 0.032), with those on Fingolimod having the highest adherence (17.3%). Treatment satisfaction was significantly higher among adherent patients (p < 0.023). The main reasons for changing prescribed drugs were the presence of attacks, i.e., response to treatment was substandard (41.8%) and the experienced side effects of used drugs (39.9%). PDDS differed significantly according to patients' treatment adherence only among those receiving interferon beta-1b, with higher mean severity score among those who were adherent (p = 0.002). Conclusions Medication adherence among MS patients in Saudi Arabia is low. Higher adherence is associated with patients' higher education. The main underlying reasons for changing prescribed drugs are the presence of attacks, substandard response to treatment, or suffering the DMDs' side effects. Medication adherence is associated with higher treatment satisfaction.