SAT0412 ACCURACY OF AN INSTRUMENT FOR SCREENING PSORIATIC ARTHRITIS AMONG PSORIATIC PATIENTS: RESULTS FROM THE MULTICENTRE ITALIAN STUDY HERACLES (SCREENING STRATEGIES FOR RHEUMATOLOGICAL REFERRAL OF PSORIATIC SUBJECTS AIMED TO DISCLOSE PSORIATIC ARTHRITIS)

Background: Identifying psoriatic arthritis (PsA) among people with psoriasis is often challenging due to low specificity of symptoms at early PsA stage and/or delayed referral to the rheumatologist. Screening instruments -assisting the dermatologist to decide when rheumatological assessment is beneficial- have potential to reduce the diagnostic delay. Objectives: To evaluate the accuracy of a dermatologist-filled-out questionnaire designed for screening PsA among psoriatic patients under dermatology care. Methods: HERACLES is a multicentre, cross-sectional study running at 9 Italian dermatology and rheumatology tertiary centres. All participants were under dermatology care for skin psoriasis. Previous diagnosis of PsA precluded eligibility. Dermatologists at each site assessed consecutive psoriatic subjects, filled in the specifically-designed HERACLES questionnaire (HQ, Figure 1) and finally referred the participants to rheumatologists for clinical evaluation. All participants filled in the ToPAS, PASE, PEST and EARP questionnaires. Rheumatologists assessed the participants regardless of the questionnaires’ scores. The gold standard applied to assess the instruments’ accuracy was the diagnosis of PsA as established by the rheumatologists. ROC curve analysis evaluated the performance of the scores associated with the clinical criteria listed in the HQ, estimating the sensitivity and specificity of different cut-off levels. Further exploratory ROC curve analysis compared HQ performance to that of the other four questionnaires tested. Results: Out of 759 subjects enrolled, 524 (69%) attended rheumatology assessment. Rheumatologists diagnosed PsA in 73/524 patients (13.9%, Figure 2). Mean age was 53 (SD 16) years and 46% were female. Mean psoriasis duration was 20 (SD 19) years. The area under the ROC curve of HQ was 0.775. The HQ score cut-off value of 2 yielded a sensitivity of 92% and a specificity of 47%; a cut-off value of 3 yielded a sensitivity of 66% and a specificity of 75%. The comparison between the ROC curve of the HQ and those of the other four questionnaires evaluated did not show any significant difference (p=0.523 versus TOPAS; p=0.201 versus PASE; p=0.345 versus PEST and p=0.240 versus EARP). Conclusion: The HERACLES questionnaire, a tool designed for dermatologists, showed good sensitivity and specificity in identifying PsA cases among subjects with cutaneous psoriasis. Acknowledgments: The HERACLES project was supported by a research grant from FIRA and Pfizer Italia SRL Disclosure of Interests: Gabriele De Marco: None declared, Maria Manara Consultant of: Consultant and/or speaker for Eli-Lilly, MSD, Sanofi-Genzyme, Novartis, Alfa Wasserman and Cellgene, Speakers bureau: Consultant and/or speaker for Eli-Lilly, MSD, Sanofi-Genzyme, Novartis, Alfa Wasserman and Cellgene, Paolo Gisondi: None declared, Luca Idolazzi: None declared, Roberta Ramonda Speakers bureau: Novartis, Celgene, Janssen, Pfizer, Abbvie, Lilly, Stefano Piaserico: None declared, Alberto Cauli: None declared, Marco Amedeo Cimmino: None declared, Veronica Tomatis: None declared, Carlo Salvarani: None declared, Rosanna Scrivo: None declared, Anna Zanetti: None declared, Greta Carrara: None declared, Carlo Alberto Scire: None declared, Angelo Cattaneo: None declared, Antonio Marchesoni Speakers bureau: Abbvie, Pfizer, UCB, Novartis, Celgene, Eli Lilly