Reproducibility and sensitivity to change of four scoring methods for the radiological assessment of osteoarthritis of the hand.

Abstract

Osteoarthritis (OA) of the hand could be a relevant model to study the progression of OA in structure-modification trials. Various methods are proposed to assess hand OA and its progression radiologically. To compare intra-reader and inter-reader precision and sensitivity to change of four radiological scoring methods proposed in hand OA. 2 trained readers scored separately 105 pairs of radiographs (baseline; year 1), selected from patients enrolled in a randomised controlled trial, for inter-reader reliability and sensitivity to change. They scored twice 60 pairs among the 105 for cross-sectional and longitudinal intra-reader reliability. Radiological hand OA assessment used: global, Kellgren-Lawrence (KL), Kallman and Verbruggen scoring methods. Inter- and intra-reader reliabilities were studied using intraclass coefficient (ICC) and the Bland-Altman method. Sensitivity to change was compared by calculating the standardised response means. Transversal intra-reader reproducibility ICCs ranged from 0.922 to 0.999. Verbruggen ranked the highest, followed by the KL and Kallman methods. Inter-rater reliability was higher for the Verbruggen scores, followed by the KL, global and Kallman scores (ICC 0.706-0.999). Longitudinal intra-reader reliability (baseline; year 1) was better using the Kallman and KL (ICC 0.986 and 0.990), followed by the Verbruggen (0.941) or global methods (0.939). Standardised response means ranged from 0.24 (KL) to 0.29 (Kallman). All four methods compared well with respect to reliabilities. However, the Verbruggen and Kallman methods performed better. The method most sensitive to change was the Kallman method, followed by Verbruggen and global scores. This study also suggests that structural changes could be detected in hand OA over a 1-year period.