Dalbeth N et al. (2007) Validation of a radiographic damage index in chronic gout. Arthritis Rheum 57: 1067–1073

Radiographic scoring of articular damage is useful for evaluating disease progression and response to treatment in patients with rheumatic diseases; currently, however, there is no validated radiographic scoring system for patients with chronic gout. Dalbeth and colleagues tested a variety of radiographic scoring systems against a consensus global score, and the method with the highest correlation with the consensus global score was evaluated for reproducibility and discriminatory accuracy.

The authors obtained radiographs of 95 proximal interphalangeal joints from 12 patients with chronic gout (median disease duration 17.5 years, range 3–38 years). These were scored by three different rheumatologists on a scale from 0 (normal) to 10 (extremely abnormal); the mean score formed the consensus global score. The same joints were then scored using the Sharp/van der Heijde erosion, Sharp/van der Heijde joint space narrowing, Ratingen destruction and Steinbrocker global scores. A combination of the Sharp/van der Heijde erosion and joint space narrowing scores showed the greatest correlation with the consensus global score (P <0.001).

This combined scoring system was then used to score hand and foot joints (including distal interphalangeal joints) in 35 different patients with chronic gout (median disease duration 16 years, range 1–46 years). The results were found to be highly reliable; the intraclass correlation coefficients for intraobserver and interobserver reproducibility were 0.993–0.998 and 0.963–0.966, respectively. In addition, the modified Sharp/van der Heijde score discriminated between early and late disease.