Performance of the Norwegian version of AUSCAN – a disease-specific measure of hand osteoarthritis

Abstract

To examine the performance of the Norwegian version of the AUSCAN Index as a disease-specific health status measure in patients with hand osteoarthritis (OA). One hundred and ninety-nine patients with clinical hand OA (mean (SD) age 61.7 (5.7) years, 18 (9%) males) underwent a comprehensive examination including joint status, examination of grip strength and completion of several self-reported health status questionnaires. The Australian/Canadian OA hand index (AUSCAN) captures three different dimensions of hand OA: pain (5 items), stiffness (1 item), and difficulties with daily activities (9 items). Our pre-study hypothesis was to identify AUSCAN as a specific hand measure with strong correlations to hand measures and lower correlations to other general measures of health. Patient completion of the AUSCAN Index was similar or better than other measures. The internal consistency of the AUSCAN was excellent. The pain and physical dimension of AUSCAN correlated substantially to each other and moderately to the stiffness scale. The AUSCAN physical scale correlated moderately to substantially to other measures, the highest correlation being seen with the Arthritis Impact Measurement Scale (AIMS) 2 hand and finger function scale (r=0.73). The standardised differences between patients with and without radiographic abnormalities were numerically larger for the AUSCAN pain and physical scales than for other measures. The Norwegian version of the AUSCAN has an acceptable clinimetric performance and is a suitable tool for assessment of hand OA.