OBJECTIVES: To study hospitalization rates in the context of physician perceived adherence and response to treatment in Brazil, comparing MS patients treated with interferon beta-1a vs other platform therapies.   METHODS: Relapsing remitting MS patients currently receiving interferon beta-1a or other platform therapies, continuously for at least the previous 12 months, were identified from the 2015 Adelphi MS Disease Specific Programme, a cross-sectional study of 412 RRMS, 81 SPMPS, and 112 PPMS patients in Brazil. Regression analyses modelled the relationship between treatment with interferon beta-1a vs treatment with other platform therapies, and number of hospitalizations in the last 12 months, physician-reported treatment response and adherence to treatment. Patient age, sex, body mass index and number of comorbid conditions were included as covariates in the models. RESULTS: