Objective: To design a quality-of-life (QOL) instrument specific for patients with knee or hip osteoarthritis and to assess its validity and reproducibility.
Methods: One-on-one or group interviews were conducted with 79 patients and 28 healthcare professionals. Of the 80 potential items identified from the results, 46 were selected based on their content and were used to develop version 1 of the OsteoArthritis of Knee and Hip Quality of Life Scale (OAKHQOL). The psychometric characteristics of the scale were evaluated in patients who met Altman's criteria for knee or hip osteoarthritis.
Results: Based on the results of psychometric analyses in 263 patients, three items were excluded, leaving 43 items in the final version (2.3) of the OAKHQOL. Principal components analysis identified four domains: physical activities, mental health, social functioning, and social support. A pain domain was individualized later. Construct validity, reproducibility, and discriminating power of the domains were satisfactory. Standardized response means after joint replacement surgery were close to 1 for the pain and physical functioning domains and equal to 0.7 for the mental health domain, indicating good sensitivity to change.
Conclusions: The OAKHQOL is the first QOL tool specifically dedicated to lower-limb osteoarthritis. It captures specific aspects of QOL in patients with knee or hip osteoarthritis and exhibits psychometric properties consistent with use in longitudinal studies.