Development and initial validation of the vasculitis damage index for the standardized clinical assessment of damage in the systemic vasculitides

OBJECTIVE: To develop and validate the Vasculitis Damage Index (VDI) for the standardized clinical assessment of damage in the systemic vasculitides. METHODS: Using a nominal group consensus approach, the Birmingham Vasculitis Group generated guiding principles for assessment of damage in all systemic vasculitides. Damage was defined as irreversible change resulting from scars. Consensus principles were developed into the VDI, including guidelines for use, a list of items of damage, and a glossary. RESULTS: For 100 surviving patients with systemic vasculitis, the median VDI score at last observation was 3 (range 0-8). Within the Wegener's granulomatosis subgroup, the median VDI score for 12 non-survivors was higher than for 47 survivors (non-survivors median score 7, interquartile range 5-8 versus survivors median score 4, interquartile range 2-5; P = 0.003). VDI scores for 100 patients with systemic vasculitis increased from initial presentation to last observation by a median score of 3 (range 1-4; P < 0.001). The VDI assesses more items and is more sensitive to change than other indices of damage (P < 0.001). Using the VDI, trained observers can produce moderately consistent damage scores. CONCLUSION: The VDI is a sensitive, reproducible, comprehensive, and credible clinical tool for quantifying damage. The data presented herein should enable further validation and testing of the VDI in specific vasculitic syndromes, and should facilitate the comparison of different therapies.