Pos0922 Comparative Study of Two Classification Criteria Sets in Real Clinical Practice in Behçet’s Disease

Background: Behçet's disease (BD) is a variable-vessel vasculitis with a high variability of clinical manifestations. Diagnosis of BD was traditionally performed according to the International Study Group (ISG) 1. Recently, criteria proposed by the International Team for the Revision of the International Criteria for BD (ITR-ICBD) have demonstrated a higher sensitivity 2. Objectives: The aim of study was to assess a) the concordance and differences between ISG and ICDB criteria b) sensitivity in diagnosing severe manifestations (ocular, vascular and neurological). Methods: The study included 142 patients diagnosed with definitive or possible BD by expert rheumatologists. They were diagnosed at a well-defined population in Northern Spain between January 1980 and November 2023. The ISG and ICBD diagnostic criteria for BD were applied to all patients and compared among them. To assess how the observed agreement proportion behaved between both diagnostic criteria, one of the criteria was added for all subjects, reassessing those who met ISG and ICBD criteria to recalculate Kappa once again. Same was done removing one of the criteria to all subjects. Results: 142 patients (73 men/ 69 women) were studied. Mean age at diagnosis was 36.4 + 13.9 years. 80 (56.3%) patients fulfilled ISG criteria and 117 (82.4%) ICBD criteria (Table 1). Concordance between both criteria was moderate (Kappa 0.43 IC 95% 0.29-0.57) with a 74% of subjects classified consistently. The highest Kappa size was observed when vascular involvement was excluded from all patients (Kappa 0.52 IC 95% 0.38-0.67), and the smallest Kappa size was observed when vascular involvement was included across all patients (Kappa 0.21 IC 95% 0.07-0.34) (Graph 1). Conclusion: ICBD criteria are more likely to diagnose BD and classify more patients with severe manifestations of the disease. The greatest changes in agreement between both diagnostic criteria for the disease were found when modifying the vascular involvement variable. REFERENCES: 1 Lancet 1990; 335:1078-80. 2 J Eur Acad Dermatology Venereol 2014;28:338-47. Acknowledgements: NIL. Disclosure of Interests: None declared.