RESUMEN
BACKGROUND: Overcrowding in emergency departments (EDs) is a worldwide challenge. As a result of the increased demand for EDs, slow internal patient flow, and unavailability of hospital beds, patients are kept in the corridors, causing a boarding effect. Studies have associated boarding in EDs with unfavorable clinical outcomes and adverse events. Thus, the purpose of this systematic review was to describe the effects of ED boarding on the occurrence of adverse events. DESIGN: We followed the Meta-Analysis of Observational Studies in Epidemiology checklist and registered this systematic review with PROSPERO (CRD42020117915). METHODS: Literature searches were performed using the databases PubMed, Scopus, Latin American and Caribbean Center on Health Sciences Information (LILACS), Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Cochrane, as well as Google Scholar, OpenThesis, and the Brazilian Digital Library of Theses and Dissertations from September to November 2019. Cohort or case control studies that evaluated the occurrence of adverse events in patients who remained in an ED, waiting for a hospital bed, were included in the review. RESULTS: Seven studies met our eligibility criteria. Boarding in EDs may be related to a reduction in the quality of care, resulting in unfavorable clinical outcomes and adverse events. CONCLUSIONS: Boarding in EDs may be related to increases in adverse incidents and events. CLINICAL RELEVANCE: The evidence in this review suggests that ED boarding increases the occurrence of unfavorable outcomes and identifies important considerations for future research.