The Australian/Canadian Osteoarthritis Hand Index in a community-dwelling population of older adults: Reliability and validity

Objective. To assess the acceptability and measurement properties of the Australian/Canadian Osteoarthritis Hand Index (AUSCAN) applied to a community-dwelling population of older adults with hand problems. Methods. Data were obtained from 2 related sources: 2,113 responders to a 2-stage cross-sectional postal survey who reported hand problems in the previous 12-months, and 55 participants with hand problems completing a clinical assessment. The AUSCAN subscales were assessed for data quality and scaling properties. Test-retest reliability was assessed in clinical participants reporting no change in their hand condition at 1 month. Construct and criterion validity were evaluated using other data from the survey and clinical assessment. Internal consistency of the subscales was tested using Cronbach's alpha and item-total correlations. Results. AUSCAN subscales had high completion rates in the survey (missing data: 2.3-2.7%). Subscale scores covered the possible range but were skewed towards lower pain, stiffness, and functional problems. Test-retest reliability estimates supported the use of the pain and stiffness subscales (rho > 0.7), with the estimate for stiffness being slightly lower (rho = 0.64). The subscales demonstrated both construct validity (significantly higher subscale scores in participants reporting a. recent general practitioner consultation for their hand problems and high correlations with hand function performance measures) and criterion validity (high correlations with generic health measures and disease-specific measures). Conclusion. The AUSCAN is a valid and reliable measure of hand problems in a community-dwelling population of older adults. The AUSCAN performs well both in terms of its internal reliability and its relationship with external constructs.