Ambulance response times and 30-day mortality: a Copenhagen (Denmark) registry study

Alexander Andrew Matthew Mills, Elisabeth Helen Anna Mills, Stig Nikolaj Fasmer Blomberg, Helle Collatz Christensen, Amalie Lykkemark Møller, Gunnar Gislason, Lars Køber, Kristian Hay Kragholm, Freddy Lippert, Frederik Folke, Mikkel Porsborg Andersen, Christian Torp-Pedersen

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

BACKGROUND AND IMPORTANCE: Ensuring prompt ambulance responses is complicated and costly. It is a general conception that short response times save lives, but the actual knowledge is limited.

OBJECTIVE: To examine the association between the response times of ambulances with lights and sirens and 30-day mortality.

DESIGN: A registry-based cohort study using data collected from 2014-2018.

SETTINGS AND PARTICIPANTS: This study included 182 895 individuals who, during 2014-2018, were dispatched 266 265 ambulances in the Capital Region of Denmark.

OUTCOME MEASURES AND ANALYSIS: The primary outcome was 30-day mortality. Subgroup analyses were performed on out-of-hospital cardiac arrests, ambulance response priority subtypes, and caller-reported symptoms of chest pain, dyspnoea, unconsciousness, and traffic accidents. The relation between variables and 30-day mortality was examined with logistic regression.

RESULTS: Unadjusted, short response times were associated with higher 30-day mortality rates across unadjusted response time quartiles (0-6.39 min: 9%; 6.40-8.60 min: 7.5%, 8.61-11.80 min: 6.6%, >11.80 min: 5.5%). This inverse relationship was consistent across subgroups, including chest pain, dyspnoea, unconsciousness, and response priority subtypes. For traffic accidents, no significant results were found. In the case of out-of-hospital cardiac arrests, longer response times of up to 10 min correlated with increased 30-day mortality rates (0-6.39 min: 84.1%; 6.40-8.60 min: 86.7%, 8.61-11.8 min: 87.7%, >11.80 min: 85.5%). Multivariable-adjusted logistic regression analysis showed that age, sex, Charlson comorbidity score, and call-related symptoms were associated with 30-day mortality, but response time was not (OR: 1.00 (95% CI [0.99-1.00])).

CONCLUSION: Longer ambulance response times were not associated with increased mortality, except for out-of-hospital cardiac arrests.

Original languageEnglish
JournalEuropean Journal of Emergency Medicine
Volume31
Issue number1
Pages (from-to)59-67
Number of pages9
ISSN0969-9546
DOIs
Publication statusPublished - 2024

Bibliographical note

Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.

Keywords

  • Humans
  • Ambulances
  • Reaction Time
  • Cohort Studies
  • Out-of-Hospital Cardiac Arrest/therapy
  • Dyspnea/diagnosis
  • Registries
  • Chest Pain
  • Unconsciousness
  • Denmark/epidemiology
  • Emergency Medical Services

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