Development of an international, multidisciplinary, patient-centered Standard Outcome Set for Multiple Sclerosis: The S.O.S.MS project

•There is need for consensus on the most important outcomes for Multiple Sclerosis.•A standard outcome set facilitates value-based care for Multiple Sclerosis.•Four domains: disease activity, symptoms, functional status and quality of life.•Multi-applicable set: monitoring, benchmarking, informing patients, research, etc.•Included outcome measures are freely available and easy to administer. Currently, outcomes of Multiple Sclerosis (MS) are not standardized and it is unclear which outcomes matter most to people living with MS. A consensus between patients and healthcare professionals on which outcomes to measure and how, would facilitate a move towards value-based MS care. to develop an internationally accepted, patient-relevant Standard Outcome Set for MS (S.O.S.MS). A mixed-method design was used, including a systematic literature review, four patient focus groups (n=30) and a RAND-modified Delphi process with seventeen MS experts of five disciplines from seven countries (the Netherlands, United States of America, Portugal, Ireland, India, New Zealand, Switzerland and Turkey). A standard outcome set for MS was defined, consisting of fourteen outcomes divided in four domains: disease activity (n=3), symptoms (n=4), functional status (n=6), and quality of life (n=1). For each outcome, an outcome measure was selected and the measurement protocol was defined. In addition, seven case-mix variables were selected. This standard outcome set provides a guideline for measuring outcomes of MS in clinical practice and research. Using this set to monitor and (inter)nationally benchmark real-world outcomes of MS can support improvement of patient value and ultimately guide the transition towards value-based MS care.