Assessment of damage in vasculitis: expert ratings of damage

Current measures of damage in vasculitis do not account for the possibility that some forms of damage may exert greater impact than others. As part of an international effort to revise how damage is quantified in vasculitis clinical research, an exercise was performed to measure expert ratings of damage items.

Members of the Vasculitis Clinical Research Consortium and European Vasculitis Study Group were given a list of 129 items of damage related to WG and microscopic polyangiitis (MPA). Participants were asked to rate each item of damage on an integer scale from 0 to 10, where 10 represented the most severe form of damage and 0 indicated 'no impact'.

A multidisciplinary panel of 50 investigators from North America, Europe and Australia-New Zealand participated. The highest median ratings (8-10) were assigned to items of damage associated with malignancy, tissue ischaemia, the central nervous system and cardiopulmonary manifestations. The mean scores ranged from 1.3 to 9.5. The highest s.d.s (>or=2.5) were associated with forms of damage that may benefit from surgical intervention or may not be causally associated with WG or MPA. Lower scores were assigned by nephrologists in comparison with rheumatologists and by Americans in comparison to Europeans, although the difference in median ranks used by these groups was not statistically significant (P > 0.05 for the comparisons).

This exercise represents an important step in the development of a weighting system that may increase the utility of damage index scores for the assessment of patients with vasculitis.