Validation of the Toronto Psoriatic Arthritis Screen II (ToPAS II) questionnaire in a Brazilian population

The Toronto Psoriatic Arthritis Screen II (ToPAS II) was developed as a tool to screen patients with probable psoriatic arthritis. We aimed to evaluate the validation of the ToPAS II questionnaire in a Brazilian population. The Portuguese translation of the ToPAS II was sent to us by the developer authors of the original index, and adapted to Brazilian Portuguese. Subjects were recruited from dermatology, general, and rheumatology outpatient clinics. After patients completed the questionnaire, they were assessed by a rheumatologist, according to standard protocol. Receiver operating characteristics (ROC) was used to obtain the sensitivity and specificity of the Brazilian Portuguese version of the ToPAS II questionnaire. One hundred and eighty-four subjects were recruited in the study. There were 70 subjects from the psoriasis group, 44 subjects from the psoriatic arthritis (PsA) group, 40 subjects from the rheumatology (non-PsA) group, and 45 healthy controls. Twenty-four patients (34.3%) in the psoriasis group had inflammatory pain and met the CASPAR classification criteria. The area under the ROC curve was 0.96, which indicates that an excellent predictor and optimum cutoff threshold to discriminate patients diagnosed with PsA used was eight as originally chosen. The overall sensitivity and specificity based on the cutoff threshold of eight were 91.3 and 90.9%, respectively. The Portuguese Brazilian version of the ToPAS II has good sensitivity and specificity and is a useful tool to screen for PsA. Key Points • Among these psoriasis patients, almost 35% in fact had psoriatic arthritis without correct diagnosis. Keeping alert of the need to disclose screening tool's use. • The TOPAS II can facilitate the screening of patients suggestive of inflammatory joint disease (with high probability of rheumatologic diagnosis) decreasing morbidity of these patients.