Osteoarthritis (OA) is one of the most common musculoskeletal diseases, with an estimated prevalence of 12% to 22% worldwide. It is the leading cause of disability among older adults, with an estimated lifetime risk of knee OA about 40% in men and 47% in women.

Clinical trials seek to determine whether treatments are safe and beneficial for patients by comparing their relative effects on outcomes chosen to identify benefit or harm. The results can then be used to make decisions on whether a treatment under investigation should be recommended. It is, therefore, essential that outcomes reported in trials are those needed by decision makers, and reflect meaningful measures for patients, clinicians, and others.