A new instrument for the screening of psoriatic arthritis among psoriatic patients

OBJECTIVES: The purpose of this study was to evaluate the performance of a dermatologist-filled-in 7-item questionnaire (called HERACLES) as a screening tool for psoriatic arthritis (PsA) in patients with psoriasis. METHODS: This study was performed in Italy in seven dermatology centres cooperating with rheumatology centres. Adults with psoriasis were consecutively recruited up to a calculated number of 750. They were invited to fill in the following questionnaires used for PsA screening: ToPAS, PASE, PEST, and EARP. The dermatologists, in addition to standard demographic and clinical data, scored each participant using a new 7-item questionnaire. All participants were later evaluated by the rheumatologists for a diagnosis of PsA. The performance of the various questionnaires was compared using receiver-operating-characteristic (ROC) area-under-the-curve (AUC) analysis. RESULTS: Of the 759 enrolled psoriatic patients, 524 (280 males and 244 females) were suitable for data analysis. PsA was diagnosed in 73 (13.9%) participants. PsA and non-PsA patient characteristics were comparable, except for arthritis-related features which were often more prevalent in the PsA group. The ROC AUC of the HERACLES instrument was 0.775 (CI: 0.722-0.828), similar to that of the other questionnaires (ToPAS 0.757; PASE 0.730; PEST 0.741; and EARP 0.739). For the HERACLES instrument, a score value of 2 yielded a sensitivity of 92% and a specificity of 47%. CONCLUSIONS: In this study, a dermatologist-filled-in questionnaire proved to be not inferior to patient-administered PsA screening tools and to be feasible. It might be an alternative (or additional) tool to screen psoriatic patients for rheumatology referral.