Abstract

GALLINO YANZI, J. et al. Validation of the composite index DAPSA (Disease Activity for Psoriatic Arthritis) in a cohort of patients with psoriasis arthritis in Argentina and determination of their cut-off values. Rev. argent. reumatolg. [online]. 2016, vol.27, n.3, pp.23-29. ISSN 0327-4411.

Objective: To validate DAPSA in patients with PsA in Argentina, evaluate its performance using other indexes, the ultrasound and establish tentative cut-off values according to disease activity. Methods: Patients with PsA according to CASPAR criteria. DAS28, DAPSA, SDAI, CDAI, and CPDAI were calculated. In 10 patients we assessed swollen joints (66) by ultrasound and calculated an ultrasound DAPSA. We tried to establish cut-off values through: the assessment of disease activity states by 10 rheumatologists through 20 hypothetical cases of patients with PsA and according to SDAI cut-off points. Finally, we validated DAPSA cut-off values in the RAPSODIA cohort. Results: We included 112 patients. DAPSA m14.3 (IQR 7-22.4). DAPSA had excellent correlation with DAS28 (Rho:0.85), CDAI (Rho:0.95), SDAI (Rho:0.94) and tender joint count (Rho:0.84). Ultrasound DAPSA m10.6 (IQR 8.5-17.9), it had excellent correlation with DAPSA (Rho:0.94). Using established cut-off values for SDAI, we performed ROC curves for DAPSA's cut-off values: ≤3.5 remission, >3.5 to ≤13.4 low, >13.4 to ≤26.2 moderate, and >26.2 high disease activity (sensitivity and specificity ≥90%, area under the curve of 98%). Conclusion: With these cut-off values is possible to define different disease activity states with a very good sensitivity and specificity.

Keywords : psoriatic arthritis; DAPSA; activity index.