Diagnostic Yield of the Light Blue Crest Sign in Gastric Intestinal Metaplasia: A Meta-Analysis

Background: The diagnostic yield of light blue crest(LBC) sign, which was observed by narrow band imaging with magnification endoscopy(NBI-ME), in detecting gastric intestinal metaplasia(IM) has shown variable results. Objective: We aimed to assess the diagnostic value of LBC under NBI-ME for detecting gastric IM. Methods: We performed a literature search of the Medline/PubMed, Embase, Web of Science, Science Direct and the Cochrane Library Databases; and a meta-analysis of pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and SROC area under the curve, using fixed-and random-effects models, for the accuracy of LBC-based IM diagnosis. Results: We initially included 4 articles, but excluded 1 article to counter significant heterogeneity. When pooled, the remaining 3 articles, which included 247 patients with 721 lesions, showed the following patterns in IM diagnosis: sensitivity: 0.90 (95% confidence interval [CI] 0.86-0.92); specificity: 0.90 (95% CI 0.86-0.93), positive likelihood ratio: 8.98 (95% CI 6.42-12.58), negative likelihood ratio: 0.12 (95% CI 0.09-0.16), and SROC area under the curve: 0.9560. Limitations: As the studies varied by their definitions for positive LBC, endoscopy types, biopsy protocols, race of patient cohort, and physicians' proficiency, some sample sizes were limited so that subgroup analyses could not be performed. Conclusion: We concluded that observing LBC under NBI-ME is an accurate and precise means of diagnosing gastric IM.