P0231 Validation and Reformation of the Red Flags Index: Build a Tool of the Early Diagnosis of Crohn's Disease
Authors: Fu X , Li J , Lu Y , Jin S , Zhu L 
Published: January 2025

Abstract

Background
Early intervention of Crohn's disease (CD) can effectively improve the prognosis. In order to identify CD in the early stage, the World IBD organization proposed the concept of "Red Flags Index (RFI)" in 2015. Various scores were added according to the clinical symptoms of patients, and RFI≥8 was defined as the threshold to distinguish CD from non-CD. Until now, no clinical research in China have verified the effectiveness of RFI in assisting the CD diagnosis. Referring to previous research, this study was designed to evaluate the effectiveness of RFI in identifying early CD, guiding the application of RFI in the early diagnosis of CD.

Methods
This study is a real-world observational cohort study. The study subjects were people who came to the Department of Gastroenterology of Wuhan Union Hospital, First Hospital of Yangtze University and Taihe Hospital from August 1, 2023 to March 31, 2024 and had lower gastrointestinal symptoms such as chronic diarrhea. They filled in the RFI questionnaire and then were followed up to record disease diagnosis and laboratory test results. Statistical methods were used to analyze the correlation between RFI degree and CD diagnosis, as well as sensitivity, specificity and other indicators.

Results
A total of 293 valid questionnaires were collected. Most of the subjects were young and middle-aged aged adults. According to the follow-up series, the majority of subjects were diagnosed with CD (54.61%), and other diagnoses included irritable bowel syndrome (IBS), bowel tuberculosis, etc. Data was analyzed and grouped according to diagnosis and RFI degree. Chi-square test showed that RFI was correlated with the incidence of Crohn's disease, with significant differences (sensitivity 72.50%, specificity 68.42%). ROC curve indicated that the model quality was great, RFI≥8 is a suitable threshold for distinguishing CD from non-CD. The diagnostic efficiency, especially the specificity of RFI≥8 combined with Fecal Calprotectin (FC)&gt;60ng/g was significantly improved compared with RFI and FC alone.

Conclusion
In this real world study, the overall model of RFI was of great quality, the threshold was appropriate, and RFI≥8 was correlated with CD diagnosis, suggesting that RFI could be used as a preliminary screening tool for early CD identification by clinicians, and RFI combined with FC can effectively improve the specificity of CD detection. However, there are differences in the identification of diseases in various items of RFI, suggesting that the weighted score of the original RFI may not fully conform to the CD characteristics in China and even in Asia. RFI items and scores can be improved according to the disease characteristics of China to build diagnostic tools with higher testing efficiency.

References
1.Fiorino G, Bonovas S, Gilardi D, et al. Validation of the Red Flags Index for Early Diagnosis of Crohn’s Disease: A Prospective Observational IG-IBD Study Among General Practitioners. J Crohns Colitis. 2020;14(12):1777-1779. doi:10.1093/ecco-jcc/jjaa111
2.Danese S, Fiorino G, Mary JY, et al. Development of Red Flags Index for Early Referral of Adults with Symptoms and Signs Suggestive of Crohn’s Disease: An IOIBD Initiative. J Crohns Colitis. 2015;9(8):601-606. doi:10.1093/ecco-jcc/jjv067