ReviewThe incidence and outcomes of out-of-hospital cardiac arrest in metropolitan versus rural locations: A systematic review and meta-analysis
Introduction
Out-of-hospital cardiac arrest (OHCA) is a significant public health issue,1 with an average global incidence of approximately 55 adult cases per 100,000 person-years,2, 3 and survival of less than 10%.1 While average survival is low, there is evidence that OHCA survival and incidence varies between jurisdictions (i.e. between nations, provinces/states, or smaller government areas).2, 3, 4, 5 Such comparisons are important in highlighting potential opportunities for improvement in the various factors that have been identified as contributing to OHCA survival.6, 7, 8 The early instigation of several modifiable factors have been shown to improve outcomes, including early recognition of cardiac arrest during emergency calls, bystander cardiopulmonary resuscitation (CPR), defibrillation, advanced life support and access to evidence-based post resuscitation care.8, 9, 10, 11.
While a large focus of geographic comparisons of OHCA incidence and survival has been between jurisdictions, another geographic basis for comparison is between rural and metropolitan (metro) populations. Studies have suggested that rurality impacts the management and survival of OHCA,5, 12 however, the full impact has not yet been thoroughly explored. Rurality is known to be a major factor impacting on many health outcomes, including aspects of cardiac health. A systematic review by Butland et al.13 noted that compared to metro areas, patients in rural areas travel further to access medical resources, and are less likely to participate in prevention strategies, particularly programs targeting cardiac health. A review by Alanazy et al.14 reported that patients in rural areas experienced longer EMS (Emergency Medical Services) response times, longer transport times to health facilities and had poorer survival rates, across a range of health conditions. The aim of this systematic review was to compare the incidence, management, and survival outcomes of OHCA between rural and metropolitan locations.
Section snippets
Methods
This systematic review was conducted and reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement.15 Prior to commencement, the systematic review methodology was registered in the International Prospective Register of Systematic Reviews (no. CRD42021270207).
Study selection
From n = 16,646 records identified in the search, 28 studies (30 papers) were selected as meeting the inclusion criteria (Fig. 1). Title and abstract screening excluded the majority of the papers, primarily due to being unrelated to OHCA, or lacking a geographical location focus. At the full text screening phase, studies were excluded on the basis of the OHCA not being attended by EMS, no exposure of any participants to a clearly defined rural environment, no direct comparison between OHCA
Results of individual studies
Table 2 summarises the patient and arrest characteristics and incidence/survival outcomes by rural/metro area for each study. The main reported outcomes were ROSC and STHD, with 17 studies26, 31, 32, 36, 43, 44, 22, 23, 39, 40, 41, 46, 47, 48, 49 comparing ROSC between rural and metro areas and 16 studies23, 31, 32, 34, 36, 38, 39, 49, 50, 42, 43, 44, 45, 46 comparing STHD. Only four studies reported survival to 30 days24, 40, 47, 48 and three reported survival to one year.24, 34, 53 We present
Discussion
This systematic review identified 28 studies (30 papers) that examined the difference between rural and metro areas in the incidence and survival outcomes of OHCA. To our knowledge, this is the first systematic review to evaluate the effect of rurality specifically on OHCA survival outcomes. Our review covered studies from a variety of locations around the world, with varying methods for determining, and definitions of, rurality. We found that the incidence of OHCA varied between studies and
Conclusion
Overall, while there was no clear difference in OHCA incidence between metro and rural areas, the crude odds of STHD are estimated to be approximately 50% lower in rural areas than metro areas. This suggests an opportunity for improvement in the prehospital management of OHCA within rural locations. This review also highlighted major challenges in standardising the definition of metro versus rural populations in the context of cardiac arrest research.
Funding
JF is funded by a National Health and Medical Research Council (NHMRC) Investigator Grant (#1174838), and AS receives a PhD Stipend Scholarship linked to this grant. SM is funded by the NHMRC Prehospital Emergency Care Centre for Research Excellence Grant (#1116453).
CRediT authorship contribution statement
Ashlea Smith: Methodology, Investigation, Data curation, Formal analysis, Writing – original draft, Project administration. Stacey Masters: Methodology, Investigation, Validation, Writing – review & editing. Stephen Ball: Methodology, Writing – review & editing, Supervision. Judith Finn: Methodology, Writing – review & editing, Supervision.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
References (63)
- et al.
Global incidences of out-of-hospital cardiac arrest and survival rates: Systematic review of 67 prospective studies
Resuscitation
(2010) - et al.
Out-of-hospital cardiac arrest across the World: First report from the International Liaison Committee on Resuscitation (ILCOR)
Resuscitation
(2020) - et al.
Regional variation in the characteristics, incidence and outcomes of out-of-hospital cardiac arrest in Australia and New Zealand: Results from the Aus-ROC Epistry
Resuscitation
(2018) - et al.
International variation in survival after out-of-hospital cardiac arrest: A validation study of the Utstein template
Resuscitation
(2019) - et al.
Post-cardiac arrest syndrome: epidemiology, pathophysiology, treatment, and prognostication. A Scientific Statement from the International Liaison Committee on Resuscitation; the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; the Council on Stroke
Resuscitation
(2008) - et al.
Recognising out-of-hospital cardiac arrest during emergency calls increases bystander cardiopulmonary resuscitation and survival
Resuscitation
(2017) - et al.
046 Bystander Cardiopulmonary Resuscitation (CPR) and use of Automated External Defibrillator (AED) for Out-of-hospital Cardiac Arrest (OHCA): Urban Versus Regional NSW
Heart Lung Circ
(2020) - et al.
for the CARES Surveillance Group. Bystander-initiated cardiopulmonary resuscitation and automated external defibrillator use after out-of-hospital cardiac arrest: Uncovering disparities in care and survival across the urban-rural spectrum
Resuscitation
(2022) - et al.
Out-of-hospital cardiac arrest: Does rurality decrease chances of survival?
Resusc Plus
(2022) - et al.
Outcomes and prevalence of adult out-of-hospital cardiac arrest (OHCA) by population density groups in the Republic of Ireland
Resuscitation
(2013)