Regression to the mean for physical function and quality of life in clinical trials for symptomatic knee osteoarthritis
Objective: To estimate the size of regression to the mean (RTM) for common patient-reported outcomes in trials for knee osteoarthritis (OA). Design: Longitudinal cohort study; we included participants of the Osteoarthritis Initiative who fulfilled typical inclusion criteria for enrolment in a trial. These included: age 40–79 years, symptomatic knee OA, Kellgren-Lawrence grade 2–3, use of pain medi
