The objective of this study was to determine health-related quality of life (HRQoL) in patients with ANCA-associated vasculitis (AAV) as measured by the "routine assessment of patient index data 3" (RAPID3) and whether RAPID3 is correlated with disease activity as determined by the Birmingham Vasculitis Activity Score (BVAS). Data from patients at an academic institution vasculitis clinic seen between Jan 2010 and Jan 2012 were collected using chart review. BVAS and RAPID3 scores were calculated at each patient visit. RAPID3 was compared between patients in remission (BVAS = 0) and patients with active disease (BVAS > =1) at all visits for four consecutive visits, when data available, at least 3 months apart during the period mentioned. Robust generalized estimating equations (GEE) in linear regression models evaluated associations between the RAPID3 and BVAS over all available observations, adjusting for intra-subject correlations. Thirty-four patients were included in the study, 26 had granulomatosis with polyangiitis (GPA), five microscopic polyangiitis (MPA), and three eosinophilic granulomatosis with polyangiitis (EGPA). Patients at first visit had impaired HRQoL as measured by RAPID3 [6.8 (3.1-12.6)]. The median RAPID3 scores were higher in patients with active disease as compared to patients in remission (7.0 vs. 3.0, p = 0.115; 8.8 vs. 1.0, p = 0.011; 6.1 vs. 2.0, p = 0.032; and 11.7 vs. 2.0, p = 0.128 for visits 1, 2, 3, and 4, respectively). In longitudinal GEE models incorporating all observations there was a strong association between the RAPID3 (per 1 unit) and BVAS (per 1 unit) [β 0.21 (0.10, 0.32) p < 0.001]. RAPID3 can be used to measure HRQoL in patients with AAV. RAPID3 correlated significantly with BVAS. RAPID3 can discriminate between disease states in AAV. This instrument may help document patient experience and add to clinical decisions.
Keywords: ANCA-associated Vasculitis; Disease activity measures; Patient-Reported Outcomes; RAPID3; Validation of measures.