Emergency medical services employing intra-arrest transport less frequently for out-of-hospital cardiac arrest have higher survival and favorable neurological outcomes

Resuscitation. 2021 Nov;168:27-34. doi: 10.1016/j.resuscitation.2021.09.004. Epub 2021 Sep 9.


Background: There is substantial regional variation in out-of-hospital cardiac arrest (OHCA) survival. We investigated whether regional emergency medical services (EMS) intra-arrest transport (IAT) practices are associated with patient outcomes.

Methods: We performed a secondary analysis of a multi-center North American clinical trial dataset, which enrolled EMS-treated adult OHCA cases from 49 regional population-based clusters. The exposure of interest was regional-level intra-arrest transport (IAT), calculated as the proportion of cases in each cluster transported to hospital prior to return of spontaneous circulation, examined as quartiles and as a continuous variable. Multilevel mixed-effects logistic regression modeling estimated the association between regional IAT with survival to hospital discharge and favorable neurologic status (modified Rankin Scale ≤ 3) at hospital discharge.

Results: Of 26,148 subjects (median age 68 years; 36% female; 23% shockable initial rhythm) 2424 (9.3%), survived to hospital discharge and 1993 (7.6%) had favourable neurological outcomes. Across regional clusters, IAT ranged from 0.84% to 75% (quartiles <6.2%, 6.2-19.6%, 19.6-30.4%, and ≥30.4%). For each quartile, 13.3%, 7.9%, 7.4%, and 4.8% survived, and 10.4%, 7.8%, 7.4%, and 4.8% had favourable neurological status. Regional IAT (per 10% change) was associated with decreased probability of survival (AOR 0.86, 95% CI 0.82-0.91) and favorable neurological outcome (AOR 0.80, 95% CI 0.76-0.85).

Conclusion: Treatment within a region that utilizes IAT less frequently was associated with improved clinical outcomes at hospital discharge. These findings may account for some of the known regional variation in OHCA outcomes.

Keywords: Emergency medical services; Heart arrest; Out-of-hospital cardiac arrest.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Cardiopulmonary Resuscitation*
  • Emergency Medical Services*
  • Female
  • Humans
  • Logistic Models
  • Male
  • Out-of-Hospital Cardiac Arrest* / therapy
  • Patient Discharge

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