The survey of patients with hip and knee osteoarthritis reported by Peters et al showed improvement or no change in a substantial proportion of patients followed up by telephone after 7 years.1 Consequently, the authors conclude that osteoarthritis does not invariably deteriorate, but such conclusions bear closer investigation. Outcome assessment involved score criteria including assessment of pain and functional activities. How though might an individual's appraisal of pain or disability reflect either ‘true’ change (physical improvement) or consideration of other …