Experienced Agencies, Faster Chute Times Determinants of EMS Response in the United States
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Abstract
Why do emergency medical units respond more rapidly to some dispatched calls than others? This study examines over 355 million emergency medical services (EMS) activations recorded in the National Emergency Medical Services Information System (NEMSIS) database between 2018 and 2023. The results show that teams operating in the top 5% of agencies by call volume—representing the most experienced systems—initiate response more quickly and post consistently shorter chute times.
Experienced responders more quickly recognize the nature of the call, develop confidence in both the likely course of events and their own ability to manage it, and initiate mobilization with minimal hesitation. As these behaviors are repeated, they become embedded in routines, coordination, and shared expectations. In this way, experienced responders shape agency-level culture from the ground up, contributing to persistent differences in performance across agencies, captured in agency-level fixed effects.
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