Emergency Medical Services Time Intervals for Acute Chest Pain in the United States, 2015-2016

Background: Chest pain is a leading complaint in emergency settings. Timely emergency medical services (EMS) responses can reduce delays to treatment and improve clinical outcomes for acute myocardial infarction patients and other medical emergencies. We investigated national-level EMS response, scene, and transport times for acute chest pain patients in the United States. Methods: A retrospective analysis was performed using 2015-2016 data from the National EMS Information System (NEMSIS). Eligible patients were identified as having a provider impression of chest pain or discomfort and not due to trauma or resulting in cardiac arrest during EMS care. Descriptive analyses of prehospital time intervals and patient-, response-, and system-level covariates were performed. Multivariable logistic regression was used to measure associations between meeting response and scene time benchmarks (8-min and 15-min, respectively) and covariates. Results: Our study identified 1,672,893 eligible EMS encounters of chest pain. Patients had a mean age of 63.1 years (SD = 14.8). The population was evenly distributed by sex (51% male; 49% female). Most encounters occurred in home or residence (58%) and had lights and sirens response to scene (84%). Most encounters were in urban areas (78%). The median (interquartile range, IQR) response time was 7 (5-10) minutes. The median (IQR) scene time was 16 (12-20) minutes. The median (IQR) transport time was 13 (8-20) minutes. Generally, median response and transport times were longer in rural and frontier areas compared to urban and suburban areas. Only 65% and 49% met the 8-min response and 15-min scene time benchmarks. Responding with lights and sirens was associated with greater compliance with EMS response time benchmark. EMS care of older age groups and females was less likely to meet the scene time benchmark. Conclusions: Substantial proportions of EMS encounters for chest pain did not meet response and scene time benchmarks. Regional and urban-rural differences were observed in adherence with the response time benchmark. Our findings also suggest age and gender disparities in on-scene delays by EMS. Our study contributes important evidence on timely EMS responses for cardiac chest pain and provides suggestions for EMS system benchmarking and quality improvement.