The Diagnostic Utility of Biochemical Markers and Intestinal Ultrasound Compared with Endoscopy in Patients with Crohn’s Disease and Ulcerative Colitis: A Systemic Review and Meta-Analysis

Background: Inflammatory bowel disease (IBD) consists of Crohn’s disease (CD) and Ulcerative colitis (UC). The main goal of treatment is to obtain mucosal healing via endoscopy. More recently, intestinal ultrasounds, along with biochemical markers, have been increasingly popular as point-of-care testing to monitor treatment response. This systemic review and meta-analysis aimed to assess the diagnostic test performance of ultrasonography and biochemical markers (C-reactive protein and fecal calprotectin) compared with endoscopy for detecting inflammation in IBD. Methods: A comprehensive literature search was conducted using PubMed Medline, EMBASE, ScienceDirect, and CINAHL from 1 January 2018 to 1 January 2024. The included studies were prospective and retrospective observational studies, clinical trials, and cross-sectional studies investigating the diagnostic sensitivity and specificity of ultrasonography, biochemical markers, and endoscopy. Studies were selected based on the Preferred Reporting Items for Systematic Review and Meta-analysis Statement (PRISMA). Results: Of the 1035 studies retrieved, 16 met the inclusion criteria, and most of the included studies were prospective observational studies. Diagnostic test accuracy was conducted, and the pooled sensitivity and specificity of all the studies revealed that ultrasonography has the highest pooled sensitivity, at 85% (95% CI, 78 to 91%), and specificity, at 92% (95% CI, 86 to 96%), as compared with biochemical markers and endoscopy. More specifically, biochemical markers had a pooled sensitivity and specificity of 85% (95% CI, 81 to 87%) and 61% (95% CI, 58 to 64%), respectively, and endoscopy had 60% (95% CI, 52 to 68%) and 82% (95% CI, 76 to 87%), respectively. However, the results also show substantial heterogeneity in the studies because of various populations, protocols, and outcomes in the studies included. This was especially noted in the assessment of biochemical markers, in which a metaregression was performed showing a nonsignificant p-value of 0.8856 for the coefficient. Conclusions: IUS was found to have the highest pooled sensitivity and specificity of all the included studies for diagnosing inflammation in patients with CD and UC, and this, coupled with biochemical markers, can improve diagnostic utility.