Correlation Between Endoscopic and Histopathological Diagnosis in Inflammatory Bowel Disease – A Two-Year Study at a Tertiary Care Center

Background: A combined retrospective and prospective correlative evaluation of endoscopic and histopathologic scores, based on data collected between April 2018 and April 2020 at VPS Lakeshore Hospital and Research Center, Nettoor, Kochi. Methods: 65 diagnosed cases of Ulcerative Colitis and 10 cases of Crohn Disease were selected. Biopsies were evaluated blindly, without going through clinical or endoscopic details. Histological activity was assessed using Gupta Index (scale 0 to 3) and Global Histologic Activity Score (scale < 2 to > 8) for Ulcerative Colitis and Crohn Disease, respectively. These were then correlated with Endoscopic activity assessed by Mayo Score (scale 0 to 3) for Ulcerative Colitis and Simple Endoscopic Score (scale: < 2 to > 15) for Crohn Disease. Statistical significance was assessed. Result: In this study, a statistically significant correlation was observed between the scales of endoscopy and histology scores of UC (p value 0.00). The best correlation was seen for Mayo Score 3. The sensitivity (93%), specificity (100%), PPV (100%) and NPV (60.0%) reveals that the MAYO score is accurately matching with GUPTA index in 94% cases. Correlation was not found to be statistically significant between SES Score and GHAS Score in Crohn Disease (p value 0.117-Chi square test for association between the scores). However, the sensitivity, specificity, PPV and NRV are 71%, 100%, 100% and 60.0% (diagnostic performance assessment), respectively. Here again, p value of 0.167 using McNemar's test indicates an insignificant value due to low sample size. The overall accuracy indicates that the SES score is accurately matching with GHAS score in 80% cases. Conclusion: A statistically significant correlation was observed between the scales of endoscopy and histology scores of UC, with 100% correlation in cases with Endoscopic Mayo score 3. However, several patients with mild or normal endoscopic findings exhibited histological evidence of inflammation. Therefore, histological assessment in Ulcerative Colitis is essential in diagnosing and for evaluating treatment outcomes and determining follow up strategies. Correlation between endoscopic and histological measures was not statistically significant in Crohn Disease, which may be due to lower number of cases. However, the overall accuracy indicates, SES Score is accurately matching with GHAS score in majority (80%) of the cases.