Reproducibility and sensitivity to change of 4 scoring methods for the radiological assessment of osteoarthritis of the hand

¹ Saint-Antoine Hospital, France
² Rheumatology Office, France
³ Universit Diderot, Paris VII, Unité d’épidémiologie clinique et de Biosta, France
⁴ Université Diderot, Paris VII, Unité d’épidémiologie clinique et d, France
⁵ Paris-Descartes University, Medicine Faculty ; AP-HP, Cochin Hospital, Rheumatology B Department, France

^* To whom correspondence should be addressed. E-mail: emaheu{at}wanadoo.fr.

Accepted 2 November 2006

	Abstract

Hand osteoarthritis (0A) could be a relevant model to study OA progression in structure-modification trials. Various methods are proposed to radiologically assess hand OA and its progression.

Objective: To compare intra-, interreader precision and sensitivity to change of 4 radiological scoring methods proposed in hand OA.

Methods: Two trained readers scored separately 105 pairs of radiographs (baseline ; year 1), selected from patients enrolled in a randomised controlled trial, for interreader reliability and sensitivity to change. They scored twice 60 pairs among the 105 for cross-sectional and longitudinal intrareader reliability. Radiological hand OA assessment used : Global ; Kellgren-Lawrence (KL) ; Kallman ; and Verbruggen scoring methods. Inter- and intrareader reliabilities were studied using intra-class coefficient (ICC) and Bland-Altman method. Sensitivity to change was compared by calculating the standardised response means (SRM).

Results: Transversal intrareader reproducibility ICCs ranged from 0.922 to 0.999. Verbruggen ranked the highest, followed by KL and Kallman methods. Interrater reliability was higher for the Verbruggen followed by the KL, global and Kallman scores (ICC : 0.706 to 0.999). Longitudinal intrareader reliability (baseline - year 1) was better using Kallman and KL (ICC 0.986 and 0.990), followed by Verbruggen (0.941) or global methods (0.939). SRMs ranged from 0.24 (KL) to 0.29 (Kallman).

Conclusion: All 4 methods compared well with respect to reliabilities. However, Verbruggen and Kallman performed better. The most sensitive to change was the Kallman followed by Verbruggen and global scores. This study also suggests that structural changes could be detected in hand OA over a 1-year period.

Keywords: Kallman, Verbruggen, Kellgren and Lawrence scales, hand OA, radiographic assessment, reliability of various scoring methods, sensitivity to change