Patient-Reported Measures of Physical Function in Knee Osteoarthritis.

Knee osteoarthritis is a common cause of an array of functional limitations in older adults, and the accurate assessment of such limitations is critical for practicing clinicians and scientists. Patient-reported measures are a valuable resource to track the type and severity of limitation, although the psychometric performance of each instrument should be thoroughly evaluated before adoption. This article reviews the validity, reliability, sensitivity to change, and responsiveness of 3 patient-reported measures of physical function: the Western Ontario and McMaster Universities Osteoarthritis Index, the Knee Injury and Osteoarthritis Outcome Score, and the Patient Reported Outcomes Measurement Information System Physical Function scale.