Comparative diagnostic accuracy of image-enhanced endoscopy modalities and artificial intelligence-assisted endoscopy for gastric intestinal metaplasia and gastric dysplasia: protocol for a systematic review and diagnostic test network meta-analysis.

introductionGastric intestinal metaplasia (GIM) and gastric dysplasia are critical precursors in the Correa cascade of gastric carcinogenesis. Although multiple image-enhanced endoscopy (IEE) modalities and artificial intelligence (AI)-assisted systems have been developed to improve their detection, the comparative diagnostic accuracy of these technologies remains unclear. Direct comparative studies are limited and conventional pairwise meta-analyses do not provide a coherent framework for comparing multiple diagnostic technologies. METHODS AND ANALYSIS: This protocol follows the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) and PRISMA-Network Meta-Analysis guidelines. We will search MEDLINE (Ovid), Embase (Ovid), the Cochrane Central Register of Controlled Trials (CENTRAL; Cochrane Library/Wiley), Web of Science Core Collection (Clarivate), Scopus (Elsevier), ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform from inception, without date or language restrictions. Eligible studies will be diagnostic accuracy studies evaluating IEE modalities (including narrow-band imaging with or without magnification, blue laser imaging, linked colour imaging and iScan) or AI-assisted endoscopy against histology. Comparative studies will form the primary evidence base for the diagnostic test network meta-analysis; single-arm studies will be summarised separately and will not contribute to the primary network estimates. The coprimary diagnostic parameters will be sensitivity and specificity for GIM and dysplasia. These will be analysed jointly using a hierarchical bivariate diagnostic test network meta-analysis with binomial likelihoods and correlated random effects. Diagnostic OR and area under the receiver operating characteristic curve will be treated as secondary summary measures. Two reviewers will independently screen, extract data and apply Quality Assessment of Diagnostic Accuracy Studies 2. Heterogeneity, transitivity and inconsistency will be assessed using prespecified clinical and methodological effect modifiers, model-based diagnostics and sensitivity analyses. The certainty of evidence will be assessed using Confidence in Network Meta-Analysis, with interpretation adapted to diagnostic accuracy outcomes. ETHICS AND DISSEMINATION: This study does not require ethical approval as it relies on secondary analysis of published literature. Findings will be disseminated through peer-reviewed publication and conference presentations. PROSPERO REGISTRATION NUMBER: CRD420261363078.