Establishing clinically meaningful within-individual improvement thresholds for eight patient-reported outcome measures in people with relapsing-remitting multiple sclerosis.

Background: As disease-modifying therapies do not reverse the course of multiple sclerosis (MS), assessment of therapeutic success involves documenting patient-reported outcomes (PROs) concerning health-related quality of life, disease and treatment-related symptoms, and the impact of symptoms on function. Interpreting PRO data involves going beyond statistical significance to calculate within-patient meaningful change scores. These thresholds are needed for each PRO in order to fully interpret the PRO data.