Abstract
Objective The Assessment of SpondyloArthritis international Society-Health Index (ASAS-HI) is a tool designed to assess disease impact in spondyloarthritis (SpA), but its clinical performance is barely known. We aimed to test the clinimetric properties of ASAS HI in a real clinical scenario.
Methods This cross-sectional study included 111 consecutive SpA patients. The measurement properties of ASAS HI were tested against conventional assessment measures. Convergent validity was assessed by Spearman's rho correlations, while discriminative validity was analyzed through ROC curves. A multivariate regression analysis was designed to identify ASAS HI items associated with active disease.
Results The average ASAS-HI was 5.4 ± 3.8 (IQR: 3-8). ASAS HI showed high convergent validity against other SpA measures (rho ≥ 0.70, p < 0.0005). The optimal criterion for detecting high / very high disease activity ASDAS categories was an ASAS-HI score > 6, area under the ROC curve 0.86 (95%CI: 0.78-0.92), +LR 7.3 (95%CI: 3.1-17.1), p < 0.0001. The ASAS-HI items significantly associated with BASDAI active disease were, "I often get frustrated" [OR 9.2 (95%CI: 1.2-69.4), p = 0.032], and, "I sleep badly at night” [OR 7.7 (95%CI: 1.4-41.6), p = 0.018). As for ASDAS, it was, “pain sometimes disrupts my normal activities” [OR 8.7 (95%CI: 1.7-45.2), p = 0.010].
Conclusion The ASAS HI is a useful and simple instrument for its application in daily practice. Given its good clinimetric properties it could be used as an additional instrument to evaluate SpA.