Clinimetric properties of the AUSCAN Osteoarthritis Hand Index: an evaluation of reliability, validity and responsiveness

OBJECTIVE: To assess the reliability, validity and responsiveness of the Australian/Canadian (AUSCAN) Osteoarthritis Hand Index in both Likert (LK) and Visual Analogue (VA)-scaled formats. METHODS: Two separate studies were conducted; the first addressing reliability and validity issues and the second addressing index responsiveness. In a group of 50 patients with osteoarthritis (OA) of the hand, test-retest reliability was assessed at a 1-week interval and internal consistency from single administrations of the Index. Construct validity was evaluated against several other outcome measures including the Functional Index for Hand Osteoarthritis (FIHOA), separate patient and physician global assessments, Doyle Index, grip strength, pinch grip, and Health Assessment Questionnaire. A 6-week washout retreatment design was used in a group of 44 OA hand patients to assess index responsiveness and comparative responsiveness against the FIHOA. RESULTS: Reliability and construct validity coefficients confirm the reliability and construct validity of both the AUSCAN LK3.0 and AUSCAN VA3.0 Indices. The washout retreatment study establishes index responsiveness and suggests that the AUSCAN LK3.0 and AUSCAN VA3.0 Indices may be more responsive than the FIHOA. CONCLUSIONS: The patient self-completed AUSCAN LK3.0 and AUSCAN VA3.0 Indices are reliable, valid and responsive and can be recommended as primary outcome measures for future hand OA clinical trials.