Abstract:

Objective Several different scales were devised to assess disease activity in anti-neutrophil cytoplasmic autoantibody(ANCA)-associated vasculitis(AAV). To investigate the reliability and correlation of these instruments, five disease activity scales were compared. Methods Totally 45 cases of AAV including 30 Wegener granulomatosis and 15 microscopic polyangitis were scored using the five disease assessment scales: the Birmingham Vasculitis Activity Score(BVAS1994), the BVAS for Wegener granulomatosis(BVAS/WG), BVAS2003, the Disease Extent Index(DEI) and the Five Factor Score(FFS). Twenty cases were rescored by the raters. All data were analyzed by SPSS statistical software. Results Reliability of the scales was high(intraclass correlations for each measure range=0.93 to 0.98).Test/retest reliability was also high for each scale(range=0.97 to 0.98). The scores by different activity assessing scales correlated significantly well, BVAS1994 and BVAS2003(rs=0.96, P<0.001), BVAS1994 and BVAS/WG(rs=0.87, P<0.001), BVAS1994 and DEI(rs=0.82, P<0.001), BVAS2003 and BVAS/WG(rs=0.87, P<0.001), BVAS2003 and DEI(rs=0.83, P<0.001), BVAS/WG and DEI(rs=0.78, P<0.001). Conclusion The scales for measuring disease activity in AAV are highly correlated and reliable. The different trial data could be compared with one another.

Key words: vasculitis, anti neutrophil cytoplasmic autoantibody, activity score