The primary objective of the study is to evaluate the real-world clinical effectiveness, as measured by the proportion of participants relapsed at 12 months, in participants treated with dimethyl fumarate (DMF). Secondary objectives of the study are: To evaluate the real-world clinical effectiveness, as measured by the proportion of participants relapsed at 12 months, in participants treated with DMF, glatiramer acetate (GA), teriflunomide, or fingolimod both in the overall participant cohort and in a subset of participants who were naïve to disease-modifying therapy (DMT) and were diagnosed with multiple sclerosis (MS) within 3 years of starting the index therapy; To compare relapse activity, defined as annualized relapse rate (ARR), among participants treated with DMF, GA, teriflunomide, or fingolimod; To compare MS-related hospitalizations among participants treated with DMF, GA, teriflunomide, or fingolimod; To compare intravenous corticosteroid use among participants treated with DMF, GA, teriflunomide, or fingolimod.