Reliability, sensitivity to change and feasibility of three radiographic scoring methods for hand osteoarthritis.

Abstract

To compare the reliability, sensitivity to change and feasibility of three radiographic scoring methods for hand osteoarthritis (OA). Baseline, 2-year and 6-year hand radiographs of 90 patients with hand OA were read in triplicate in chronological order by three readers from different European centres using the OARSI atlas (OARSI), Kellgren--Lawrence grading scale (KL) and Verbruggen--Veys anatomical phase score (VV). Reliability was determined using intraclass correlation coefficients and smallest detectable change (SDC). Sensitivity to change was assessed by the proportion of progression above the SDC. Feasibility was reflected by the mean performance time. Intra- and inter-reader reliability was similar across methods. Inter-reader SDCs (% maximum score) for KL, OARSI and VV were 2.9 (3.2), 4.1 (2.9) and 2.7 (1.8) over 2 years and 3.8 (4.1), 4.6 (3.3) and 4.0 (2.5) over 6 years, respectively. KL detected a slightly higher proportion of progression. There were differences between readers, despite methods to enhance consistency. The mean performance time (SD, minutes) for KL, OARSI and VV was 4.3 (2.5), 9.3 (6.0) and 2.8 (1.5), respectively. Methods had comparable reliability and sensitivity to change. Global methods were fastest to perform. For multicentre trials use of a central reading centre and multiple readers may minimise inter-reader variation.