Factors Associated with Therapeutic Adherence in Multiple Sclerosis in Spain

Purpose: Adherence to disease-modifying therapies (DMTs) in multiple sclerosis (MS) is a complex and multidimensional phenomenon. Identifying the predictors of therapeutic adherence in MS will guide the design of interventions to improve health outcomes. Our aim was to assess the degree of adherence to pharmacological treatments, assess the relationship between patient-related factors and pharmacological adherence and to identify predictors of adherence to pharmacological treatments in patients with MS in Spain.Patients and Methods: A cross-sectional nationwide study was carried out in Spain between December 2020 and September 2021. The web-based evaluation protocol consisted of a self-questionnaire survey designed ad hoc and the application of validated questionnaires to assess adherence, as well as beliefs about medication and quality of life. Predictor variables of adherence to MS treatment were assessed using multivariate analysis.Results: A total of 152 patients with MS participated (mean age: 44 years; 64% were female; and 78% had relapsing-remitting MS). Seventy-three percent of the patients reported being adherent to their pharmacological treatment for MS. Forgetfulness was the most common cause of non-adherence. Necessity beliefs and concerns beliefs were not statistically associated with adherence. The adherent group shows statistically significant better levels of quality of life in the cognitive function subscale than the non-adherent participants (p=0.040). Role limitations-emotional, emotional well-being and overall quality of life were not significantly associated with adherence. Predictors with a statistical association with adherence to treatment were years of education (OR=0.79; 95% CI: 0.65- 0.96; p=0.020) and intravenous treatment (OR=3.17; 95% CI: 1.07-9.45; p=0.038).Conclusion: We found an adequate adherence to pharmacological treatment. Low education and intravenous treatment were significant predictors of adherence to DMTs.