Inter- and Intraobserver Variability on Endoscopic Scoring Systems in Crohn's Disease and Ulcerative Colitis: A Systematic Review and Meta-Analysis

Background Endoscopy scoring is a key component in the diagnosis of ulcerative colitis (UC) and Crohn's disease (CD). Variability in endoscopic scoring can impact patient trial eligibility and treatment effect measurement. In this study, we examine inter- and intraobserver variability of inflammatory bowel disease endoscopic scoring systems in a systematic review and meta-analysis.Methods We included observational studies that evaluated the inter- and intraobserver variability using UC (endoscopic Mayo Score [eMS], Ulcerative Colitis Endoscopic Index of Severity [UCEIS]) or CD (Crohn's Disease Endoscopic Index of Severity [CDEIS], Simple Endoscopic Score for Crohn's Disease [SES-CD]) systems among adults (>= 18 years of age) and were published in English. The strength of agreement was categorized as fair, moderate, good, and very good.Results A total of 6003 records were identified. After screening, 13 studies were included in our analysis. The overall interobserver agreement rates were 0.58 for eMS, 0.66 for UCEIS, 0.80 for CDEIS, and 0.78 for SES-CD. The overall heterogeneity (I2) for these systems ranged from 93.2% to 99.2%. A few studies assessed the intraobserver agreement rate. The overall effect sizes were 0.75 for eMS, 0.87 for UCEIS, 0.89 for CDEIS, and 0.91 for SES-CD.Conclusions The interobserver agreement rates for eMS, UCEIS, CDEIS, and SES-CD ranged from moderate to good. The intraobserver agreement rates for eMS, UCEIS, CDEIS, and SES-CD ranged from good to very good. Solutions to improve interobserver agreement could allow for more accurate patient assessment, leading to richer, more accurate clinical management and clinical trial data. This study examined the inter- and intraobserver variability of inflammatory bowel disease endoscopic scoring systems (endoscopic Mayo Score, Ulcerative Colitis Endoscopic Index of Severity, Crohn's Disease Endoscopic Index of Severity, Simple Endoscopic Score for Crohn's Disease) in a systematic review and meta-analysis.