Epidemiology of pre-hospital outcomes of out-of-hospital cardiac arrest in Queensland, Australia

The reality of rurality: Understanding the impact of remoteness on out-of-hospital cardiac arrest in Western Australia - A retrospective cohort study

INTRODUCTION

Western Australia (WA) spans a large, sparsely-populated area of Australia, presenting a challenge for the provision of Emergency Medical Service (EMS), particularly for time-critical emergencies such as out-of-hospital cardiac arrest (OHCA).

OBJECTIVE

To assess the impact of rurality on the epidemiology, incidence and survival of OHCA in WA.

METHODS

We conducted a retrospective cohort study of EMS-attended OHCA in WA from 2015 to 2022. Incidence was calculated on all OHCAs, but the study cohort for the multivariable regression analysis of rurality on survival outcomes consisted of OHCAs of medical aetiology with EMS resuscitation attempted. Rurality was categorised into four categories, derived from the Australian Standard Geographic Classification - Remoteness Areas.

RESULTS

The age-standardised incidence of EMS-attended OHCA per 100 000 population increased with increasing remoteness: Major Cities = 104.9, Inner Regional = 123.3, Outer Regional = 138.0 and Remote = 103.9. Compared to Major Cities, the adjusted odds for return of spontaneous circulation (ROSC) at hospital were lower in Inner Regional (aOR = 0.71, 95%CI 0.53-0.95), Outer Regional (aOR = 0.62, 95%CI 0.45-0.86) and Remote areas (aOR = 0.52, 95%CI 0.35-0.77) but there was no statistically significant difference for 30-day survival. Relative to Major Cities, Regional and Remote areas had longer response times, shorter transport-to-hospital times, and higher rates of bystander CPR and automated external defibrillator use.

CONCLUSIONS

Out-of-hospital cardiac arrest in rural areas had lower odds of ROSC at hospital compared to metropolitan areas, despite adjustment for known prognostic covariates. Despite WA's highly sparse regional population, these differences in ROSC are consistent with those reported in other international studies.

Incidence, characteristics, and prehospital outcomes of out-of-hospital cardiac arrest in Qatar: a nationwide gender-based investigation

BACKGROUND

Research on incidence and characteristics of Out-of-Hospital Cardiac Arrest (OHCA) in the Middle East is limited. We assessed the incidence, prehospital characteristics, and outcomes of OHCA in Qatar, a Middle Eastern country. Subsequently, we performed gender-specific analysis.

METHODS

This was a retrospective examination of data obtained from the OHCA registry at Hamad Medical Corporation (HMC) in Qatar from 2017 to 2022. We included adults, non-traumatic, EMS-treatment OHCA. We calculated the incidence of adult OHCA and conducted descriptive analyses for prehospital characteristics, and prehospital outcomes presented by return of spontaneous circulation (ROSC). We evaluated gender differences in prehospital characteristics and ROSC using Student's t-test and the Chi-Square test as appropriate. Furthermore, we conducted a multivariable logistic regression analysis to investigate the correlation between gender and achieving ROSC.

RESULTS

We included 4,306 adult OHCA patients, with 869 (20.2%) being females. The mean annual incidence of adult OHCA was 27.4 per 100,000 population-year. Males had a higher annual incidence of OHCA than females. Among all cases, 36.3% occurred in a public location, 25.8% had an initial shockable rhythm, and 28.8% achieved ROSC. Males had a higher proportion of bystander CPR, arrests in public locations, and initial shockable rhythms. While unadjusted analysis showed no significant gender differences in achieving ROSC, adjusted analysis revealed that male gender was associated with higher odds of achieving ROSC (adjusted OR male vs. female 1.38, 95% CI 1.15-1.66, p < 0.001).

CONCLUSIONS

Approximately 720 adults undergo non-traumatic OHCA in Qatar every year, with a higher incidence observed in males. Male gender was associated with higher odds of achieving ROSC. Further gender-specific research in OHCA intervention and outcome in the Middle East is required.

Application of the Australian Bureau of Statistics Socio-Economic Indexes for Areas in cardiovascular disease research: a scoping review identifying implications for research

Objective To scope how the Australian Bureau of Statistics Socio-Economic Indexes for Areas (SEIFA) has been applied to measure socio-economic status (SES) in peer-reviewed cardiovascular disease (CVD) research. Methods The Joanna Briggs Institute's scoping review methodology was used. Results The search retrieved 2788 unique citations, and 49 studies were included. Studies were heterogeneous in their approach to analysis using SEIFA. Not all studies provided information as to what version was used and how SEIFA was applied in analysis. Spatial unit of analysis varied between studies, with participant postcode most frequently applied. Study quality varied. Conclusions The use of SEIFA in Australian CVD peer-reviewed research is widespread, with variations in the application of SEIFA to measure SES as an exposure. There is a need to improve the reporting of how SEIFA is applied in the methods sections of research papers for greater transparency and to ensure accurate interpretation of CVD research.

Epidemiology and outcome of out-of-hospital cardiac arrest in Salt Lake City: Sex-based investigations

Objectives

Prior research indicates sex disparities in the incidence and outcomes of out-of-hospital cardiac arrest (OHCA). This study investigates the presence of such differences in Salt Lake City, Utah.

Methods

We analyzed data from the Salt Lake City Fire Department (2008‒2023). We included adults with non-traumatic OHCA. We calculated the annual incidence of OHCA and examined sex-specific survival outcomes using multivariable logistic regression, adjusting for OHCA characteristics known to be associated with survival.

Results

The annual incidence of OHCA was 76 per 100,000 person-years. Among the 894 OHCA cases included in the analysis, 67.5% were males, 37.3% achieved return of spontaneous circulation (ROSC), and 13.6% survived hospital discharge. Unadjusted analysis revealed that males had significantly higher OHCA in public locations (43.9% vs. 28.6%), witnessed arrests (54.5% vs. 47.8%), and shockable rhythms (33.3% vs. 22.9%). Males also showed higher rates of ROSC (37.5% vs. 36.9%), hospital discharge survival (14.5% vs. 11.7%), and neurologically intact survival. After adjusting for the OHCA characteristics, there was no significant differences between males and females in ROSC, survival to hospital discharge, and favorable neurological function with adjusted odds ratios (male vs. female) of 0.92 (95% confidence interval [CI] 0.73‒1.16), 0.85 (95% CI 0.59‒1.22), and 0.92 (95% CI 0.62‒1.40), respectively.

Conclusion

Approximately, 128 adults suffer OHCA in Salt Lake City annually. Males initially showed higher crude survival rates, but after adjusting for OHCA characteristics, no significant sex differences in survival outcomes were found. Enhancing OHCA characteristics could benefit both sexes. Investigations into the relationship between sex- and region-specific factors influencing OHCA outcomes are needed.

The incidence and outcomes of out-of-hospital cardiac arrest in metropolitan versus rural locations: A systematic review and meta-analysis

BACKGROUND/AIMS

Rurality poses a unique challenge to the management of out-of-hospital cardiac arrest (OHCA) when compared to metropolitan (metro) locations. We conducted a systematic review of published literature to understand how OHCA incidence, management and survival outcomes vary between metro and rural areas.

METHODS

We included studies comparing the incidence or survival of ambulance attended OHCA in metropolitan and rural areas, from a search of five databases from inception until 9th March 2022. The primary outcomes of interest were cumulative incidence and survival (return of spontaneous circulation, survival to hospital discharge (or survival to 30 days)). Meta-analyses of OHCA survival were undertaken.

RESULTS

We identified 28 studies (30 papers- total of 823,253 patients) across 13 countries of origin. The definition of rurality varied markedly. There was no clear difference in OHCA incidence between metro and rural locations. Whilst there was considerable statistical heterogeneity between studies, the likelihood of return of spontaneous circulation on arrival at hospital was lower in rural than metro locations (OR = 0.53, 95% CI 0.40, 0.70; I² = 89%; 5 studies; 90,934 participants), as was survival to hospital discharge/survival to 30 days (OR = 0.52, 95% CI 0.38, 0.71; I² = 95%; 15 studies; 18,837 participants).

CONCLUSIONS

Overall, while incidence did not vary, the odds of OHCA survival to hospital discharge were approximately 50% lower in rural areas compared to 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 rurality in the context of cardiac arrest research.

Mastering Linked Datasets: The Future of Emergency Health Care Research

Objectives: The aim of this work is to describe routine integration of prehospital emergency health records into a health master linkage file, delivering ongoing access to integrated patient treatment and outcome information for ambulance-attended patients in Queensland.Methods: The Queensland Ambulance Service (QAS) data are integrated monthly into the Queensland Health Master Linkage File (MLF) using a linkage algorithm that relies on probabilistic matches in combination with deterministic rules based on patient demographic details, date, time and facility identifiers. Each ambulance record is assigned an enduring linkage key (unique patient identifier) and further processing determines whether each record matches with a corresponding hospital emergency department, admission or death registry record. In this study, all QAS electronic ambulance report form (eARF) records from October 2016 to December 2018 where at least 1 key linkage variable was present (n = 1,771,734) were integrated into the MLF.Results: The majority of records (n = 1,456,502; 82.2%) were for transported patients, and 90.1% (n = 1,312,176) of these transports were to public hospital facilities. Of these transport records, 93.9% (n = 1,231,951) matched to emergency department (ED) records and 59.3% (n = 864,394) also linked to admitted patient records. Of ambulance non-transport records integrated into the MLF, 23.6% (n = 74,311) matched with ED records.Conclusion: This study demonstrates robust linkage methods, quality assurance processes and high linkage rates of data across the continuum of care (prehospital/emergency department/admitted patient/death) in Queensland. The resulting infrastructure provides a high-quality linked dataset that facilitates complex research and analysis to inform critical functions such as quality improvement, system evaluation and design.

Sex Differences in Incidence and Outcome of Out-of-Hospital Cardiac Arrest Within a Local Health Network

Introduction

Sex and gender differences in presentation and characteristics of out-of-hospital cardiac arrest (OHCA) are established in cohorts with presumed cardiac aetiology but not non-cardiac etiology. This study investigated the effect of sex on incidence and outcome of OHCA according to presumed and adjudicated aetiology within a local health network.

Methods

Population-based observational cohort study of emergency medical services (EMS) attended OHCAs within an Australian local health network. Cases identified from an EMS registry between 2012-2016 were linked to a hospital registry. Age-standardised incidence and baseline characteristics were stratified by sex for EMS-treated OHCA, non-EMS witnessed presumed cardiac and obvious non-cardiac sub-cohorts, and hospitalised cases. Logistic regression was used to explore the primary outcome of survival to hospital discharge.

Results

We identified 2,024 EMS-attended and 780 EMS-treated OHCAs. The non-EMS witnessed sub-cohorts comprised 504 presumed cardiac and 168 obvious non-cardiac OHCAs. Adjudicated aetiology was recorded in 123 hospitalised cases. Age-standardised incidence for women was almost half that of men across all groups. Across cohorts, women were generally older and arrested with a non-shockable initial rhythm in an area of low socioeconomic status. There was no sex difference in the primary outcome for the main EMS-treated cohort or in the non-cardiac sub-cohorts. The sex difference in outcome in the presumed cardiac sub-cohort was not present after multivariable adjustment.

Conclusions

There are sex differences in incidence and outcome of EMS-treated OHCA that appear to be driven by differences in susceptibility to cardiac arrhythmias and underlying etiology, rather than treatment delays or disparities.

"Motorcycle Ambulance" Policy to Promote Health and Sustainable Development in Large Cities

INTRODUCTION

Motorcycles can be considered a new form of smart vehicle when taking into account their small and modern structure and due to the fact that nowadays, they are used in the new role of ambulance to rapidly reach emergency patients in large cities with traffic congestion. However, there is no study regarding the measuring of access time for motorcycle ambulances (motorlances) in large cities of Thailand.

STUDY OBJECTIVE

This study aims to compare access times to patients between motorlances and conventional ambulances, including analysis of the use of automated external defibrillators (AEDs) installed on motorlances to contribute to the sustainable development of public health policies.

METHODS

A cross-sectional study was conducted on all motorlance operations in Emergency Medical Services (EMS) at Srinagarind Hospital, Thailand from January 2019 through December 2020. Data were recorded using a national standard operation record form for Thailand.

RESULTS

Two hundred seventy-one motorlance operations were examined over a two-year period. A total of 52.4% (N = 142) of the patients were male. The average times from dispatch to vehicle (motorlance and traditional ambulance) being en route (activation time) for motorlance and ambulance in afternoon shift were 0.59 minutes and 1.45 minutes, respectively (P = .004). The average motorlance response time in the afternoon shift was 6.12 minutes, and ambulance response time was 9.10 minutes at the same shift. Almost all of the motorlance operations (97.8%) were found to have no access to AED equipment installed in public areas. The average time from dispatch to AED arrival on scene (AED access time) was 5.02 minutes.

CONCLUSION

The response time of motorlances was shorter than a conventional ambulance, and the use of AEDs on a motorlance can increase the chances of survival for patients with cardiac arrest outside the hospital in public places where AEDs are not available.

Outcomes following out-of-hospital cardiac arrest in the aeromedical retrieval population of the remote Top End of the Northern Territory, Australia

OBJECTIVE

Out-of-hospital cardiac arrest is an event with an extremely poor prognosis. There is limited literature on the outcomes for regional Australia, with none specifically addressing remote populations. We aimed to assess out-of-hospital cardiac arrest outcomes in the aeromedical retrieval population of the Top End Medical Retrieval Service.

DESIGN

We retrospectively identified all cardiac arrests, deaths and patients who had cardiopulmonary resuscitation within the aeromedical retrieval database for a 5-year period from January 2012 to December 2016.

SETTING

Retrieval patients across the Top End of the Northern Territory, Australia.

PARTICIPANTS

All patients within the cohort with a non-traumatic out-of-hospital cardiac arrest.

MAIN OUTCOME MEASURES

Data were collected on outcomes as per Utstein definitions, along with patient demographics, retrieval timings and interventions.

RESULTS

Seventy-five patients suffering cardiac arrest were identified, with 58 having a non-traumatic arrest in an out-of-hospital setting. The median age of the cohort was 40 years, and 53% had an initial shockable rhythm. Return of spontaneous circulation was achieved in 55% and 43% survived to hospital. The survival to hospital discharge and 28 days were 31% and 29%, respectively.

CONCLUSIONS

Although the study has a small sample size and limitations on generalisability due to the restricted nature of the cohort selection, the results suggest a 28-day survival rate is potentially comparable to other regions of Australia and the rest of the world. Further research needs to be undertaken in out-of-hospital cardiac arrest in remote regions to establish a true population-based cohort and ascertain where improvements can be made.

Sex differences in incidence of out-of-hospital cardiac arrest across ethnic and socioeconomic groups: A population-based cohort study in the Netherlands

BACKGROUND

Insight into the occurrence of out-of-hospital cardiac arrest (OHCA) within general populations may help to target prevention strategies. Case registries suggest that there may be substantial differences in emergency medical service (EMS)-attended OHCA incidence between men and women, but relative sex differences across ethnic groups and socioeconomic (SES) groups have not been studied. We investigated sex differences in OHCA incidence, overall and across these subgroups.

METHODS

We performed a retrospective population-based cohort study, combining individual-level data on ethnicity and income (as SES measure) from Statistics Netherlands of all men and women aged ≥25 years living in one study region in the Netherlands on 01-01-2009 (n = 1,688,285) with prospectively collected EMS-attended OHCA cases (n = 5676) from the ARREST registry until 31-12-2015. We calculated age-standardised incidence rates of OHCA. Sex differences were assessed with Cox proportional hazards regression analyses, adjusted for age, ethnicity and income, in the overall population, and across ethnic and SES groups.

RESULTS

The age-standardised incidence rate of OHCA was lower in women than in men (30.9 versus 87.3 per 100,000 person-years), corresponding with a hazard ratio (HR) of 0.33 (95% confidence interval [CI] 0.31-0.35). These sex differences in hazard for OHCA existed in all income quintiles (HR range: 0.30-0.35) and ethnic groups (HR range: 0.19-0.40), except among Moroccans (HR 0.89, 95% CI 0.51-1.57).

CONCLUSION

Women have a substantial, yet lower OHCA incidence rate than men. The magnitude of these sex differences did not vary across social strata.

Applying a set of termination of resuscitation criteria to paediatric out-of-hospital cardiac arrest

OBJECTIVE

Prehospital Termination of Resuscitation (TOR) protocols for adults can reduce the number of futile transports of patients in cardiac arrest, yet similar protocols are not widely available for paediatric out-of-hospital cardiac arrest (POHCA). The objective of this study was to apply a set of criteria for paediatric TOR (pTOR) from the Maryland Institute for Emergency Medical Services Systems (MIEMSS) to a large national cohort and determine its association with return of spontaneous circulation (ROSC) after POHCA.

METHODS

We identified patients ages 0-17 treated by Emergency Medical Services (EMS) with cardiac arrest in 2019 from the ESO dataset and and applied the applicable pTOR certeria for medical or traumatic arrests. We calculated predictive test characteristics for the outcome of prehospital ROSC, stratified by medical and traumatic cause of arrest.

RESULTS

We analyzed records for 1595 POHCA patients. Eighty-eight percent (n = 1395) were classified as medical. ROSC rates were 23% among medical POHCA and 27% among traumatic POHCA. The medical criteria correctly classified >99% (322/323) of patients who achieved ROSC as ineligible for TOR. The trauma criteria correctly classified 93% (50/54) of patients with ROSC as ineligible for TOR. Of the five misclassified patients, three were involved in drowning incidents.

CONCLUSIONS

The Maryland pTOR criteria identified eligible patients who did not achieve prehospital ROSC, while reliably excluding those who did achieve prehospital ROSC. As most misclassified patients were victims of drowning, we recommend considering the exclusion of drowning patients from future pTOR guidelines. Further studies are needed to evaluate the long-term survival and neurologic outcome of patients misclassified by pTOR criteria.

Long-term outcomes of adult out-of-hospital cardiac arrest in Queensland, Australia (2002-2014): incidence and temporal trends

OBJECTIVE

To describe annual incidence and temporal trends (2002-2014) in incidence of long-term outcomes of adult out-of-hospital cardiac arrest (OHCA) of presumed cardiac aetiology attended by Queensland Ambulance Service (QAS) paramedics, by age, gender, geographical remoteness and socioeconomic status (SES).

METHODS

This is a retrospective cohort study. Cases were identified using the QAS OHCA Registry and were linked with entries in the Queensland Hospital Admitted Patient Data Collection and the Queensland Registrar General Death Registry. Population data were obtained from the Australian Bureau of Statistics to calculate incidence. Inclusion criteria were adult (18+ years) residents of Queensland who suffered OHCA of presumed cardiac aetiology and survived to hospital admission. Analyses were undertaken by three mutually exclusive outcomes: (1) survival to less than 30 days (Surv<30 days); (2) survival from 30 to 364 days (Surv30-364 days); and (3) survival to 365 days or more (Surv365+ days). Incidence rates were calculated for each year by gender, age, remoteness and SES. Temporal trends were analysed.

RESULTS

Over the 13 years there were 4393 cases for analyses. The incidence of total admitted events (9.72-10.13; p<0.01), Surv30-364 days (0.18-0.42; p<0.05) and Surv365+ days (1.94-4.02; p<0.001) increased significantly over time; no trends were observed for Surv<30 days. An increase in Surv365+ days over time was observed in all remoteness categories and most SES categories.

CONCLUSION

Evidence suggests that implemented strategies to improve outcomes from OHCA have been successful and penetrated groups living in more remote locations and the lower socioeconomic groups. These populations still require focus. Ongoing reporting of long-term outcomes from OHCA should be undertaken using population-based incidence.

Incidence, bystander emergency response management and outcomes of out-of-hospital cardiac arrest at exercise and sport facilities in Australia

OBJECTIVE

Despite growing emphasis on automated external defibrillators (AEDs) at sport venues in Australia, the risk of cardiac events at such locations is unknown. The aim of the present study was to investigate the incidence of out-of-hospital cardiac arrest (OHCA) at exercise and sport facilities (ESF) in Australia and the impact of effective bystander-initiated CPR and AED use on return of spontaneous circulation (ROSC) to hospital admission.

METHODS

Data were obtained from the Queensland Ambulance Service for the 8-year period between January 2007 and January 2015. Data were analysed using descriptive statistics, non-parametric correlational tests and logistic regression. The OHCA incidence rate (IR) for ESF categories was standardised for 100 000 participant-years.

RESULTS

Over the 8-year period, there were 250 OHCA events with a median age of 62 years (interquartile range 49-69) comprising mostly males (86.6%, n = 187). The risk of OHCA for 100 000 participants per year was highest at outdoor sports facilities (IR 5.1) followed by indoor sports or fitness facilities (IR 0.8). On arrival of paramedics, bystander-initiated CPR and AED was present at 12.4% (n = 31) of the cases achieving 33.3% (n = 9) ROSC to hospital admission. The odds of ROSC for effective CPR was 2.3 times the odds of ROSC for no CPR (P = 0.01).

CONCLUSION

These findings have implications for policy development by government agencies and major sport and exercise organisations to improve bystander CPR and AED. This can help to ensure that ESF can properly respond to cardiac emergencies to save lives.