Mass Gathering Preparedness Requires Integrated EMS and Hospital Surge CapacityBetter ways to manage medical emergencies at large public events

Mass gatherings can generate concentrated, time-dependent demand across in-event health services, municipal emergency medical services (EMS), emergency departments, and inpatient services. Evidence relevant to preparedness is heterogeneous and is often reported with inconsistent denominators, limiting direct comparison. This structured narrative review synthesizes published evidence on EMS and hospital surge-capacity integration across the four surge domains of staff, stuff/supplies, space, and systems. The review retained the original structured search of MEDLINE/PubMed, Embase, Scopus, Web of Science, and the Cochrane Library for 2010-February 2026 and incorporated a focused PubMed and citation update through September 2026. Because the purpose is interpretive synthesis rather than exhaustive effect estimation, no de novo meta-analysis or pooled estimates were produced; quantitative findings are reported with the denominators and analytic context used by the source publications. A 2025 scoping review of 41 papers reported medical-doctor presence in 34/41 papers (82.9%), medication interventions in 23/41 (56.1%), procedural interventions in 23/41 (56.1%), health-support systems in 18/41 (43.9%), mobile treatment spaces in 23/41 (56.1%), and temporary structures in 21/41 (51.2%). That review reported median calculated patient-presentation and transport-to-hospital rates of 6.2 and 0.35 per 1,000 attendees, respectively, whereas a separate 22-article stadium review reported much lower medians when standardized per 10,000 spectators. Hospital effects were directionally heterogeneous: a 14-study systematic review found event-associated emergency-department changes ranging from 7.5%–37% decreases to increases as high as 83% in specific settings. Digital integration has shown promising simulated gains, but clinical effectiveness remains insufficiently validated. Preparedness is best treated as an integrated continuum rather than as separate event-site and hospital plans. Standardized denominators, linked patient-level data, context-specific resource design, and prospective evaluation are priorities.