SAT0316 Validation of Novel Simplified Radiographic Damage Index for Affected Joints in Chronic Gout Arthritis: A Preliminary Proposal

Background The evaluation of radiographic damage in inflammatory arthritis has been considered important, because structural damage of affected joints impairs the functional status of patients with various inflammatory rheumatic diseases and increases their economic problems and mortality [1, 2]. However, there has still been no relevant radiographic index for damage of affected joints in patients with chronic gouty arthritis. Modified SvdH scoring method has been proposed to be an alternative method [3], however, it seems to be so complex and also lack of relevance to use in clinical practice. Objectives The aim of this study was to develop and validate more a simple method to score radiographic damage measurement in patients with chronic gout. Methods Two independent observers read foot x-rays using the DAmagE index of GoUt score method (DAEGU score) and the modified Sharp/van der Heijde (SvdH) method. The 10 metatarsophalangeal (MTP) and 2 interphalangeal (IP) joints of the first toes of both feet from 15 patients with chronic gout were scored on plain radiography for erosion and joint space narrowing (JSN) (180 total joints). The intraobserver and interobserver reliability were analyzed by intraclass correlation coefficient (ICC) and minimal detectable change (MDC). The correlation between the DAEGU and SvdH methods was analyzed using Spearman9s correlation coefficients and Kappa coefficients. Results The intraobserver and interobserver ICCs for the DAEGU method were 0.945–0.987 and 0.993–0.996, respectively. The MDC at the 95% confidence interval (MDC95) showed 0.5–2.1 and 0.3–0.7 in the intra- and interobserver analyses, respectively. Strong positive correlations were represented between the DAEGU and SvdH methods for each radiological abnormality including erosion, JSN, and total score (correlation coefficients: r =0.870–0.985, p Conclusions This study demonstrated that the DAEGU score had a high reproducibility and strongly correlated with SvdH. The DAEGU method may provide a more easy assessment of structural damage in patients with chronic gout. References Kavanaugh A, et al. J Rheumatol 2004;31:849–55. Gladman DD, et al. Arthritis Rheum 1998;41:1103–10. Dalbeth N, et al. Arthritis Rheum 2007;57:1067-73. Disclosure of Interest None declared