Sensitivity and Specificity of Composite Indices of Remission in Male and Female Patients With Psoriatic Arthritis: A Multicenter Cross-Sectional Study of Longitudinal Cohorts

Objective: The aim was to evaluate the sex differences in sensitivity, specificity, positive and negative predictive values, and likelihood ratio of the outcome indices minimal disease activity (MDA), Disease Activity Score for Psoriatic Arthritis (DAPSA), and Psoriatic Arthritis Impact of Disease (PsAID) with respect to clinical remission, evaluated from both the physician and patient perspective, in a multicenter cohort of patients with PsA. Methods: In this cross-sectional analysis of 2 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 values ≤ 4 were considered as remission) and MDA was also evaluated. Patient and physician global assessment values ≤ 1 were considered as a surrogate of remission from the patient and physician perspective, respectively. Results: Two hundred seventy-two patients with PsA were enrolled (mean age 55.7 [SD 12.4]; 141 male, 131 female). In both sexes, MDA had good sensitivity and specificity toward remission as assessed by the rheumatologist. Remission according to DAPSA had excellent values of specificity but lacks sensitivity in both sexes. PsAID ≤ 4 had excellent values of sensitivity but lacked specificity in both sexes. Remission defined by DAPSA values was found to be more sensitive and specific in female patients (45.4% and 100%, respectively) than in male patients (33.3% and 84.2%, respectively) with respect to physician-judged remission. Conclusion: The results of this study demonstrate for the first time, to our knowledge, that some differences between the 2 sexes on the different outcome indices are possible. This could be important in the clinical management of patients with PsA.