Validation of the revised International Criteria for Behcet's Disease (ICBD) in Iran

The first internationally agreed criteria for Behcet's disease were the International Study Group (ISG) criteria. It had very high specificity, but lacked good sensitivity, missing an important subset of patients. The International Criteria for Behcet's Disease (ICBD) were created in 2006 to overcome this lack of sensitivity. It was revised in 2010. The objective of this study was to evaluate the performance of the revised International Criteria for Behcet's Disease (rICBD) in Iran. In this study, the ISG and ICBD were evaluated and compared to the rICBD. All patients from the Behcet's Disease Registry (7,011) and controls (5,226), up to March 2013, entered the study. The diagnosis was clinical, by expert opinion. Sensitivity, specificity, and accuracy were calculated for ISG, ICBD, and rICBD. A 95% confidence interval (95%CI) was calculated for percentages. For ISG, the sensitivity was 77.5% (95%CI = 76.5-78.5). It was 98.3% for ICBD (95%CI = 98.0-98.6) and 96.8% for rICBD (95%CI = 96.4-97.2). Specificity was 99.2% (95%CI = 99.0-99.4) for ISG, 96.2% for ICBD (95%CI = 95.7-96.7), and 97.2% for rICBD (95%CI = 96.8-97.6). Accuracy was 86.7% (95%CI = 86.1-87.3) for ISG, 97.4% for ICBD (95%CI = 97.1-97.7), and 97.0% for rICBD (95%CI = 96.7-97.3). In Iranian patients, ICBD has 20.8% and rICBD 19.3% higher sensitivity than ISG. Although the specificity was lower than ISG by 3% for ICBD and 2% for rICBD, the accuracy was higher respectively by 10.7 and 10.3%. ICBD has by far better performance than ISG. The difference was even more prominent in Iranian patients than for the ICBD cohort of patients and controls.