Sensitivity and specificity of composite indices of remission in males and females with psoriatic arthritis: a multicenter cross-sectional study of longitudinal cohorts.

The aim was to evaluate the sex differences in sensitivity, specificity, positive/negative predictive value and likelihood ratio of the outcome indices MDA, DAPSA and PsAID, in respect to clinical-judged remission, evaluated by both physician's and patients' perspective, in a multicenter cohort of PsA patients. In this cross-sectional analysis of two longitudinal cohorts, all patients with PsA consecutively attending our Rheumatology units were considered potentially eligible for the study. In all patients a complete clinical examination was carried out. The DAPSA was calculated for each patient (DAPSA≤4 values were considered as remission) and MDA was also evaluated. Patient's (PtGA) and Physician (PGA) global assessment values ≤1 were considered as a surrogate of remission by patients' and physician perspective, respectively. 272 patients with PsA were enrolled (mean age/SD: 56/12.2; males=141; females=131). In both sexes, MDA has a good sensitivity and specificity towards remission assessed by the rheumatologist. Remission according to DAPSA has excellent values of specificity but lacks sensitivity in both sexes. PsAID≤4 has excellent values of sensitivity but lacks specificity in both sexes. Remission defined by DAPSA values was found to be more sensitive and specific in females (sens. 45.4%, spec. 100%) than in males (sens. 33.3%, spec. 84.2%) in respect to physician's judged remission. The results of the study, to our knowledge first on sex differences, demonstrate that some differences between the two sexes on the different outcome indices are possible. This could be important in the clinical management of PsA patients.