Validity and responsivenes of the measure of activity performance of the hand (map-hand) in patients with hand osteoarthritis

Background: The Measure of Activity Performance of the Hand (MAP-Hand) is reliable and valid in patients with rheumatoid arthritis. Objective: To assess the validity and responsiveness of the MAP-Hand in patients with hand osteoarthritis. Methods: Patients were recruited from 2 rheumatology centres. The internal consistency of the MAP-Hand was assessed by Cronbach's á. Content validity was evaluated based on patient interviews. Construct validity and responsiveness were based on predefined hypotheses of correlation between the MAP-Hand and concurrent measures. Results: Ten men and 201 women, mean age 62.8 years (standard deviation (SD) 6.8) and disease duration 12.5 (SD 7.5) years were included. A Cronbach's á of 0.86 was determined. All 18 items in the MAP-Hand were described in the interviews. Sixty-seven percent of the correlation coefficients for baseline scores and 75% for change scores were in correspondence with the predefined hypotheses. A high correlation was found between the MAP-Hand and the Australian/ Canadian Hand Osteoarthritis Index function score at baseline (rho = 0.76). A moderate correlation was found for change scores (rho = 0.52). Conclusion: The content of the MAP-Hand adequately reflects described activity limitations in patients with hand osteoarthritis. The results suggest that the MAP-Hand has adequate internal consistency and responsiveness. Before the MAPHand is used in patients with hand osteoarthritis, evaluations of reliability and further construct validity are warranted.