The protocol for OPTIMISE:MS, a pragmatic, prospective observational study to address the need for, and challenges with, real world pharmacovigilance in multiple sclerosis, has been published. The study aims to estimate the frequency of serious adverse events with disease modifying therapy use in routine clinical practice, recruiting people with multiple sclerosis from major MS care clinics across the UK. In the UK disease modifying therapy use is driven by national prescribing guidelines, making it an ideal setting to gather multiple sclerosis outcomes data. First author Ruth Dobson, from the Preventive Neurology Unit said : A rigorously conducted observational study with a focus on pharmacovigilance has the potential to provide important data to inform clinicians and patients while testing the reliability of estimates from pivotal trials when applied to patients in the UK. The first patient was recruited in May 2019, and in January 2021 1615 individuals had baseline data recorded. The study is planned to run for seven years in the first instance, with the potential for longer follow-up subject to funding.