Validation of the Toronto Psoriatic Arthritis Screening 2 (TOPAS-2) questionnaire in an Argentinian population

Abstract

IntroductionToPAS-2 is a questionnaire designed to detect cases of psoriatic arthritis (PsA) in patients with psoriasis (PsO). ObjectiveTo validate the ToPAS-2 questionnaire in patients with psoriasis in Argentina. Materials and methodsPatients ≥18 years old with a diagnosis of PsO. As a control group, patients diagnosed with PsA (CASPAR criteria) and osteoarthritis (OA) (ACR criteria) were included. All patients completed the ToPAS-2 questionnaire and were then evaluated by a rheumatologist. Blood tests were performed to determine Rheumatoid Factor (RF) and erythrocyte sedimentation rate (ERS). Radiographs of the hands, feet, panoramic view of the pelvis, Ferguson, and lumbar and cervical spine were performed. Statistical analysisDescriptive statistics. ROC curves for determination of sensitivity, specificity, and cut-off points of the questionnaire. A p<.05 was considered significant. Results126 patients were evaluated, 54.8% female with a mean age of 54.5 (±14.9) years. The mean schooling was 10.4 (±4.1) years. A total of 45.2% had a diagnosis of PsA, 38.9% of PsO, and 15.9% of OA. The ToPAS-2 result was X 8.4 (±3.6). The mean age according to the groups was 55.5 (±12.5), 48.1 (±15.3), and 67.1 (±11.3) years, with 40.4% female, 57.1%, and 90% respectively. The mean of the ToPAS-2 according to the different groups was 11 (±2.3), 6.8 (±3.0), and 4.6 (±1.9) (p<.01 between all groups) for APs, PsO, and OA, respectively. Of the 49 patients with PsO, 16 patients were diagnosed as PsA, after evaluation by the rheumatologist. The mean ToPAS-2 in these patients was significantly higher than those not diagnosed as PsA [10.1 (±1.8) vs 5.2 (±2)] (p<.001). In the ROC curve analysis, the area under the curve was .97 (95% CI .94–.97). A TOPAS cut-off value of 8.5 had a sensitivity of 88.9% and a specificity of 96% for the diagnosis of PsA. ConclusionThe ToPAS-2 questionnaire proved to be a valid, sensitive, and specific tool for the detection of PsA in patients with psoriasis.