What question did this study set out to answer?

This study aims to examine how quickly dispatchers recognize out-of-hospital cardiac arrests and how this affects patients' survival and recovery outcomes.

April 13, 2026Open Access

Impact of early cardiac arrest recognition by emergency medical service dispatchers on out-of-hospital cardiac arrest: a retrospective population-based observational study

Key Points

This study aims to examine how quickly dispatchers recognize out-of-hospital cardiac arrests and how this affects patients' survival and recovery outcomes.
Retrospective population-based study in Nara, Japan
Analyzed Utstein-style OHCA data and DACPR records from January 2016 to December 2019
Included cases where lay rescuers performed CPR per dispatcher instructions
Used multivariable logistic regression to assess associations
Looked at differences in outcomes for witnessed and non-witnessed OHCAs.
The median OHCA recognition time was 74 seconds.
Longer dispatcher recognition time correlated with slightly higher odds of return of spontaneous circulation in the overall group.
For witnessed OHCAs, longer recognition time was linked to lower odds of return of spontaneous circulation.
No significant association was found between dispatcher recognition delay and overall survival or neurological outcomes.

Abstract

Dispatch-assisted cardiopulmonary resuscitation (DACPR) improves out-of-hospital cardiac arrest (OHCA) outcomes. However, there is no established gold standard for DACPR performance. This study aimed to investigate the association between time to OHCA recognition by the dispatcher and return of spontaneous circulation (ROSC), survival, and favorable neurological outcome. We conducted this retrospective population-based study using Utstein-style OHCA data and DACPR records between January 2016 and December 2019 in Nara, Japan. OHCA cases were included if lay rescuers performed CPR following dispatcher instructions. Patients aged < 18 years, emergency medical service-witnessed OHCAs, patients for whom CPR was already initiated at the emergency call, cases where CPR was not indicated, and cases in which callers did not follow dispatcher instructions were excluded. The primary outcome was the association between time to OHCA recognition by the dispatcher and ROSC. The secondary outcomes included 1-month survival and favorable neurological outcome (cerebral performance category 1 or 2). Multivariable logistic regression was performed to examine the association between dispatcher recognition time and outcomes. Dispatcher recognition time was modeled per 10-s increase. Stratified analyses were also performed for witnessed and non-witnessed OHCA cases. We analyzed 1,959 cases of OHCA. The median OHCA recognition time was 74 s. Longer dispatcher recognition time was associated with slightly higher odds of ROSC in the overall cohort (adjusted odds ratio aOR per 10-s increase, 1.01; 95% confidence interval CI, 1.00–1.02) and lower odds of ROSC in witnessed OHCA (aOR, 0.98; 95% CI, 0.96–0.99), whereas no clear association was observed in non-witnessed OHCA (aOR, 1.02; 95% CI, 0.99–1.04). Delay in OHCA recognition by dispatchers was not significantly associated with survival or neurological outcomes. The association between dispatcher recognition time and ROSC differed according to arrest context. In witnessed OHCA, longer dispatcher recognition time was associated with lower odds of ROSC. These findings suggest that minimizing dispatcher recognition delay may be particularly important in witnessed OHCA cases.

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Cite This Study

Yamamoto et al. (Sat,) studied this question.

synapsesocial.com/papers/69dc88b93afacbeac03ea75c https://doi.org/https://doi.org/10.1186/s12245-026-01213-1

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