Model and Empirical Data-Based Cost-Utility Studies of Continuous Glucose Monitoring in Individuals with Type 1 Diabetes: A Protocol of a Systematic Review on Methodology and Quality.

INTRODUCTION: This review aims to critically appraise differences in methodology and quality of model-based and empirical-data-based cost-utility studies to address key limitations, opportunities, and challenges to inform future cost-utility analyses of continuous glucose monitoring (CGM) in type 1 diabetes. This protocol is registered at PROSPERO (CRD42023391284). METHODS: The review will be conducted in accordance with the PRISMA guideline for systematic reviews. Searches will be conducted in MEDLINE, Embase, Web of Science, Cochrane Library, and Econlit from 2000 to January 2023. Model and empirical data-based studies evaluating the cost-utility of any CGM system in type 1 diabetes will be considered for inclusion. Studies that only report on cost per life year or any other clinical outcome, or reporting only costs or only clinical outcomes studies in type 2 diabetes populations, and studies on bi-hormonal closed loops and do-it-yourself hybrid closed loop devices will be excluded. Two reviewers will independently screen each study for inclusion. Data on the intervention, population, model settings (such as perspective, time horizon), model type and structure, clinical outcomes used to populate the model, validation, and uncertainty will be extracted and qualitatively synthesised. Quality will be assessed using the Philips et al. 2006 (model-based studies) or Consensus Health Economic Criteria (empirical data-based studies) checklists. Model validation will be assessed using the AdViSHE checklist. DISCUSSION: Now that CGM is being used more broadly in practice, critical appraisal of existing cost-utility methodology and quality is important to inform future cost-utility analyses of CGM in type 1 diabetes in various settings.