Medication adherence in patients with myasthenia gravis in Brazil: a cross-sectional study

Advances in the treatment of MG have allowed most patients to effectively treat their disorder with oral medications. In parallel, non-adherence to medication treatment regimens is a worldwide health problem. Other chronic neurological disorders have already been associated with low adherence to treatment. However, the literature regarding adherence among patients with MG is definitely poor. The purpose of this study was to capture the prevalence and the associated factors of non-adherence to pharmacological treatment in patients with MG. We carried out a cross-sectional cohort study with 58 consecutive patients with MG from a university-affiliated referral hospital in São Paulo, Brazil. We registered clinical and sociodemographic data and patients were classified according to the MGFA classification. Clinical severity was assessed with myasthenia gravis composite (MGC) scale. Neuropsychiatric symptoms were evaluated with the Hospital Anxiety and Depression Scale (HADS) and quality of life with the 15-Item Quality Of Life Instrument for myasthenia gravis scale (MG-QOL15). Adherence to pharmacological treatment was evaluated using the 8-item Morisky Medication Adherence Scale (MMAS-8). There were 26 (44.8%) patients adherent to treatment. Low adherence was associated with poor educational attainment, longer time of disease and greater daily number of pills (p < 0.05). Patients with poor compliance to treatment presented worse quality of life and increased neuropsychiatric symptoms (p < 0.05). Adherence can be relatively challenging in patients with MG. Medical approach should recognize that therapeutic success in the treatment of MG goes through adherence to treatment.