Risk Factors for Poor Adherence to Betaferon® Treatment in Patients with Relapsing-Remitting Multiple Sclerosis or Clinically Isolated Syndrome

INTRODUCTION Adherence to treatment, including early treatment discontinuation, in patients with multiple sclerosis or clinically isolated syndrome can be affected by: treatment tolerability, route of drug administration, patient age, disease duration, comorbidities, medical care, and support from their caregivers. AIM This study aimed to identify the risk factors for poor adherence to Betaferon® treatment, including early discontinuation and omitting doses. MATERIALS AND METHODS 852 adult patients treated with Betaferon participated in this 24-month study. All patients were interviewed using the Risk of Drop-out Questionnaire, the Center for Epidemiologic Studies Depression Scale and the Kurtzke Expanded Disability Status Scale. RESULTS Patients who stopped therapy were younger (p = 0.003) had a higher mean EDSS score (p = 0.022), higher mean number of relapses (p = 0.017), and reported more often fear of injection (p = 0.027) and adverse events (p = 0.007) than those who did not stop treatment. Comparing patients who stopped therapy in the first and the second year, patients who stopped therapy in the first year of treatment more frequently reported flu-like symptoms and fever, and those who stopped therapy in the second year reported-ineffectiveness of treatment and disease progression. Multivariable logistic regression models confirmed that young age, short disease duration, advanced and progressing disease, and poor Betaferon tolerability were related to premature treatment discontinuation. The risk of omitting a dose during therapy was increased in patients who were working or studying, who had more advanced disease or more adverse events, and in patients who received less support from their caregivers. CONCLUSIONS Several reasons may lead to problems with adherence to Betaferon treatment. Patients at higher risk of discontinuing treatment need to be identified early to make caregivers' support available to them.