Impacts of emergency medical technician configurations on outcomes of patients with out‐of‐ hospital cardiac arrest

Paramedics can provide advanced life support (ALS) for patients with out‐of‐hospital cardiac arrest (OHCA). However, the impact of emergency medical technician (EMT) configuration on their outcomes remains debated. A three‐year cohort study consisted of non‐traumatic OHCA adults transported by ALS teams was retrospectively conducted in Tainan City using an Utstein-style population database. The EMT‐paramedic (EMT‐P) ratio was defined as the EMT‐P proportion out of all on‐scene EMTs. Among the 1357 eligible cases, the median (interquartile range) number of on‐scene EMTs and the EMT‐P ratio were 2 (2–2) persons and 50% (50%–100%), respectively. The multivariate analysis identified five independent predictors of sustained return of spontaneous circulation (ROSC): younger adults, witnessed cardiac arrest, prehospital ROSC, prehospital defibrillation, and comorbid diabetes mellitus. After adjustment, every 10% increase in the EMT‐P ratio was on average associated with an 8% increased chance (adjusted odds ratio [aOR], 1.08; p < 0.01) of sustained ROSC and a 12% increase change (aOR, 1.12; p = 0.048) of favorable neurologic status at discharge. However, increased number of on‐scene EMTs was not linked to better outcomes. For nontraumatic OHCA adults, an increase in the on‐scene EMT‐P ratio resulted in a higher proportion of improved patient outcomes.