The primary objective of the study is to determine the incidence, type, and pattern of serious adverse events (SAEs), including but not limited to infections (including opportunistic infections), hepatic events, malignancies, and renal events, and of adverse events (AEs) leading to treatment discontinuation in patients with MS treated with dimethyl fumarate (DMF). Secondary objectives of this study in this population are as follows: To determine dimethyl fumarate (DMF) prescription and utilization patterns in routine clinical practice in patients with multiple sclerosis (MS); To assess the effectiveness of dimethyl fumarate (DMF) on multiple sclerosis (MS) disease activity and disability progression in routine clinical practice as determined by the Expanded Disability Status Scale (EDSS) score and multiple sclerosis (MS) relapse information; and To assess the effect of dimethyl fumarate (DMF) on health-related quality of life, healthcare resource consumption, and work productivity.