Comparison of the Birmingham Vasculitis Activity Score and the Five-Factor Score to Assess Survival in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: A Study of 550 Patients From Spain (REVAS Registry)

Objective To compare the accuracy of the Birmingham Vasculitis Activity Score (BVAS), version 3, and the Five Factor Score (FFS), version 1996 and version 2009, to assess survival in antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Methods A total of 550 patients withAAV(41.1% with granulomatosis with polyangiitis, 37.3% with microscopic polyangiitis, and 21.6% with eosinophilic granulomatosis with polyangiitis), diagnosed between 1990 and 2016, were analyzed. Receiver operating characteristic (ROC) curves and multivariable Cox analysis were used to assess the relationships between the outcome and the different scores. Results Overall mortality was 33.1%. The mean +/- SD BVASat diagnosis was 17.96 +/- 7.82 and was significantly higher in nonsurvivors than in survivors (mean +/- SD20.0 +/- 8.14 versus 16.95 +/- 7.47, respectively;P< 0.001). The mean +/- SD1996FFSand 2009FFSwere 0.81 +/- 0.94 and 1.47 +/- 1.16, respectively, and were significantly higher in nonsurvivors than in survivors (mean +/- SD1996FFS1.17 +/- 1.07 versus 0.63 +/- 0.81 [P< 0.001] and 2009FFS2.13 +/- 1.09 versus 1.15 +/- 1.05 [P< 0.001], respectively). Mortality rates increased according to the different 1996FFSand 2009FFScategories. In multivariate analysis,BVAS, 1996FFS, and 2009FFSwere significantly related to death (P= 0.007,P= 0.020,P< 0.001, respectively), but the stronger predictor was the 2009FFS(hazard ratio 2.9 [95% confidence interval 2.4-3.6]). When the accuracy ofBVAS, 1996FFS, and 2009FFSto predict survival was compared in the global cohort,ROCanalysis yielded area under the curve values of 0.60, 0.65, and 0.74, respectively, indicating that 2009FFShad the best performance. Similar results were obtained when comparing these scores in patients diagnosed before and after 2001 and when assessing the 1-year, 5-year, and long-term mortality. Correlation amongBVASand 1996FFSwas modest (r = 0.49;P< 0.001) but higher than betweenBVASand the 2009FFS(r = 0.28;P< 0.001). Conclusion BVASandFFSare useful to predict survival inAAV, but the 2009FFShas the best prognostic accuracy at any point of the disease course.