Abstract
BACKGROUND: Health information exchanges (HIEs) have proliferated over the last decade, but a gap remains in our understanding of their benefits to patients and the healthcare system. In this systematic review, we provide an updated report on what is known regarding the impacts of HIE on clinical, health care utilization, and cost outcomes in the adult inpatient setting. METHODS: We searched Pubmed, Web of Science, Embase, Cochrane, and Ebsco databases for citations published between January 2015 and August 2021. Eligible studies were English-language experimental or observational studies. We assessed risk of bias via the National Heart Lung and Blood Institute's Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. RESULTS: We identified 11 eligible studies-1 quasi-experimental and 10 observational. Five studies examined readmission rates and 3 found benefits from HIE. Three studies examined mortality with 2 finding benefits from the availability of HIE. Eight studies examined utilization and cost outcomes with 2 finding benefits from HIE, 1 finding poorer outcomes with HIE, and the others finding no impact. CONCLUSIONS: Evidence for the impacts of HIE remains largely observational with little direct measure of HIE use during clinical care, making causality difficult to assess. The highly variable outcomes examined by these studies limit meaningful synthesis. The strength of evidence is low that HIE reduces unplanned readmissions and mortality and there is insufficient evidence for the impact of HIE on cost or utilization. The increased number of studies specific to inpatient settings that examine objective outcomes with more rigorous statistical methods is a promising development since prior reviews. TRIAL REGISTRATION: PROSPERO 2021 CRD42021274049 Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021274049 AMENDMENTS TO PROTOCOL: Initially planned use of the Newcastle-Ottawa quality assessment scale was substituted for the National Heart Lung and Blood Institute's Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies as it was better suited to evaluate the primarily retrospective observational cohort studies identified in the review.