Regions of High Out-Of-Hospital Cardiac Arrest Incidence and Low Bystander CPR Rates in Victoria, Australia

Rural Out-of-Hospital Cardiac Arrest Patients More Likely to Receive Bystander CPR: A Retrospective Cohort Study

OBJECTIVES

Survival from out-of-hospital cardiac arrests (OHCA) remains lower in rural areas. Longer Emergency Medical Services (EMS) response times suggests that rural OHCA survival may need to rely more on early bystander intervention. This study compares the rates of bystander Cardiopulmonary Resuscitation (CPR) between rural and urban areas and examines societal factors associated with bystander CPR.

METHODS

This study was a retrospective cohort study using merged county-level data from the National Emergency Medical Services Information System (NEMSIS) sample from 2019 and 2020, the 2019 American Community Survey, and the Bureau of Health Care Workforce data. We included all adults (age ≥ 18) with OHCA who were treated by an EMS clinician reporting data to NEMSIS, with the primary exposure of OHCA rurality, and the primary outcome of bystander CPR by a member of the public. Rurality was assigned using the Rural Urban Commuting Area code associated with the OHCA location. Cases were excluded if there was an indication for witnesses identified as health care personnel, the incident occurred at a health care site, or geographical data were not available. The association between patient- and community-level covariates and bystander CPR were measured using generalized estimating equations to model the adjusted odds ratios (aOR) and 95% confidence intervals (CI), clustering on county.

RESULTS

A total of 99,171 OHCA patients were identified and 60.9% (n = 60,380) received bystander CPR. Patients with OHCA living in isolated small rural towns (aOR: 1.57, 95%CI: 1.28-1.91) were more likely to have bystander CPR when compared to those living in urban cities. The odds of bystander CPR was lower in counties with larger populations of those without high school diplomas (e.g. >15% vs ≤6%, aOR: 0.56; 95%CI: 0.51-0.61), non-Caucasian populations (e.g. >40% vs ≤10%, aOR: 0.83; 95%CI: 0.76-0.91), and older populations (e.g. >14% vs ≤9%, aOR: 0.82; 95%CI: 0.74-0.91).

CONCLUSIONS

We observed lower rates of bystander CPR in communities with lower education, higher rates of non-Caucasian populations, and older populations. Our findings emphasize the need for public interventions in bystander CPR training to meet the needs of diverse community characteristics, and particularly in areas where EMS response times may be longer.

Strategic placement of volunteer responder system defibrillators

Volunteer responder systems (VRS) alert and guide nearby lay rescuers towards the location of an emergency. An application of such a system is to out-of-hospital cardiac arrests, where early cardiopulmonary resuscitation (CPR) and defibrillation with an automated external defibrillator (AED) are crucial for improving survival rates. However, many AEDs remain underutilized due to poor location choices, while other areas lack adequate AED coverage. In this paper, we present a comprehensive data-driven algorithmic approach to optimize deployment of (additional) public-access AEDs to be used in a VRS. Alongside a binary integer programming (BIP) formulation, we consider two heuristic methods, namely Greedy and Greedy Randomized Adaptive Search Procedure (GRASP), to solve the gradual Maximal Covering Location (MCLP) problem with partial coverage for AED deployment. We develop realistic gradually decreasing coverage functions for volunteers going on foot, by bike, or by car. A spatial probability distribution of cardiac arrest is estimated using kernel density estimation to be used as input for the models and to evaluate the solutions. We apply our approach to 29 real-world instances (municipalities) in the Netherlands. We show that GRASP can obtain near-optimal solutions for large problem instances in significantly less time than the exact method. The results indicate that relocating existing AEDs improves the weighted average coverage from 36% to 49% across all municipalities, with relative improvements ranging from 1% to 175%. For most municipalities, strategically placing 5 to 10 additional AEDs can already provide substantial improvements.

Spatio-temporal distribution, prediction and relationship of three major acute cardiovascular events: Out-of-hospital cardiac arrest, ST-elevation myocardial infarction and stroke

Background

Predicting the incidence of time-sensitive cardiovascular diseases like out-of-hospital cardiac arrest (OHCA), ST-elevation myocardial infarction (STEMI), and stroke can reduce time to treatment and improve outcomes. This study analysed the spatio-temporal distribution of OHCAs, STEMIs, and strokes, their spatio-temporal correlation, and the performance of different prediction algorithms.

Methods

Adults who experienced an OHCA, STEMI, or stroke in Canton Ticino, Switzerland from 2005 to 2022 were included. Datasets were divided into training and validation samples. To estimate and predict the yearly per-capita population incidences of OHCA, STEMI, and stroke, the integrated nested Laplace approximation (INLA), machine learning meta model (MLMM), the Naïve prediction method, and the exponential moving average were employed and compared. The relationship between OHCA, STEMI, and stroke was assessed by predicting the incidence of one condition, considering the lagged incidence of the other two as explanatory variables.

Results

We included 3,906 OHCAs, 2,162 STEMIs, and 2,536 stroke patients. INLA and MLMM yearly predicted incidence OHCA, STEMI, and stroke at municipality level with very high accuracy, outperforming the Naïve forecasting and the exponential moving average. INLA exhibited errors of zero or one event in 82%, 87%, and 72% of municipalities for OHCA, STEMI, and stroke, respectively, whereas ML had errors in 81%, 89%, and 71% of municipalities for the same conditions. INLA had a prediction error of 0.87, 0.77, and 1.50 events per year per municipality for OHCA, STEMI and stroke, whereas MLMM of 0.70, 0.74, and 1.09 events, respectively. Including in the INLA model the lagged absolute values of the other conditions as covariates improved the prediction of OHCA and stroke but not STEMI. MLMM predictions were consistently the most accurate and did not benefit from the inclusion of the other conditions as covariates. All the three diseases showed a similar spatial pattern.

Conclusions

Prediction of incidence of OHCA, STEMI, and stroke is possible with very high accuracy using INLA and MLMM models. A robust spatio-temporal correlation between the 3 pathologies exists. Widespread implementation in clinical practice of prediction algorithms may allow to improve resource allocation, reduce treatment delays, and improve outcomes.

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.

Identifying areas of Australia with high out-of-hospital cardiac arrest incidence and low bystander cardiopulmonary resuscitation rates: A retrospective, observational study

AIM

This study aims to explore regional variation and identify regions within Australia with high incidence of out-of-hospital cardiac arrest (OHCA) and low rates of bystander cardiopulmonary resuscitation (CPR).

METHOD

Adult OHCAs of presumed medical aetiology occurring across Australia between 2017 and 2019 were mapped onto local government areas (LGA) using the location of arrest coordinates. Bayesian spatial models were applied to provide "smoothed" estimates of OHCA incidence and bystander CPR rates (for bystander-witnessed OHCAs) for each LGA. For each state and territory, high-risk LGAs were defined as those with an incidence rate greater than the state or territory's 75th percentile and a bystander CPR rate less than the state or territory's 25th percentile.

RESULTS

A total of 62,579 OHCA cases attended by emergency medical services across 543 LGAs nationwide were included in the study. Nationally, the OHCA incidence rate across LGA ranged from 58.5 to 198.3 persons per 100,000, while bystander CPR rates ranged from 45% to 75%. We identified 60 high-risk LGAs, which were predominantly located in the state of New South Wales. Within each region, high-risk LGAs were typically located in regional and remote areas of the country, except for four metropolitan areas-two in Adelaide and two in Perth.

CONCLUSIONS

We have identified high-risk LGAs, characterised by high incidence and low bystander CPR rates, which are predominantly in regional and remote areas of Australia. Strategies for reducing OHCA and improving bystander response may be best targeted at these regions.

Higher rates but similar causes of young out-of-hospital cardiac arrest in rural Australian patients

OBJECTIVE

To determine whether young rural Australians have higher rates or different underlying causes of out-of-hospital cardiac arrest (OHCA).

DESIGN

A case-control design identified patients experiencing an OHCA, then compared annual OHCA rates and underlying causes in rural versus metropolitan Victoria. OHCA causes were defined as either cardiac or non-cardiac, with specific aetiologies including coronary disease, cardiomyopathy, unascertained cause of arrest, drug toxicity, respiratory event, neurological event and other cardiac and non-cardiac. For OHCAs with confirmed cardiac aetiology, cardiovascular risk profiles were compared.

SETTING

A state-wide prospective OHCA registry (combining ambulance, hospital and forensic data) in the state of Victoria, Australia (population 6.5 million).

PARTICIPANTS

Victorians aged 1-50 years old experienced an OHCA between April 2019 and April 2020.

MAIN OUTCOME MEASURES

Rates and underlying causes of OHCA in young rural and metropolitan Victorians.

RESULTS

Rates of young OHCA were higher in rural areas (OHCA 22.5 per 100 000 rural residents vs. 13.4 per 100 000 metropolitan residents, standardised incidence ratio 168 (95% CI 101-235); confirmed cardiac cause of arrest 12.1 per 100 000 rural residents versus 7.5 per 100 000 metropolitan residents, standardised incidence ratio 161 (95% CI 71-251). The underlying causation of the OHCA and cardiovascular risk factor burden did not differ between rural and metropolitan areas.

CONCLUSION

Higher rates of OHCA occur in young rural patients, with standardised incidence ratio of 168 compared to young metropolitan residents. Rural status did not influence causes of cardiac arrest or known cardiovascular risk factor burden in young patients experiencing OHCA.

Spatiotemporal variation in the risk of out-of-hospital cardiac arrests in Queensland, Australia

BACKGROUND

Spatiotemporal analysis of out-of-hospital cardiac arrest (OHCA) risk is essential to design targeted public health strategies. Such information is lacking in the state of Queensland and Australia more broadly.

METHODS

We developed a spatiotemporal Bayesian model accounting for spatial and temporal dimensions, space-time interactions, and demographic factors. The model was fit to data of all OHCA cases attended by paramedics in Queensland between January 2007 and December 2019. Parameter inference was performed using the integrated nested Laplace approximation method. We estimated and thematically mapped area-year risk of OHCA occurrence for all 78 local government areas (LGAs) in Queensland.

RESULTS

We observed spatial variability in OHCA risk among the LGAs. Areas in the north half of the state and two areas in the south exhibited the highest risk; whereas OHCA risk was lowest in the west and south west parts of the state. Demographic factors did not have significant impact on the heterogeneity of risk between the LGAs. An overall trend of modestly decreasing risk of OHCA was found.

CONCLUSIONS

This study identified areas of high OHCA risk in Queensland, providing valuable information to guide public health policy and optimise resource allocation. Further research is needed to investigate the specifics of the areas that may explain their risk profile.

Characteristics of Restart a Heart 2019 event locations in the UK

Introduction

Restart a Heart (RSAH) is an annual CPR mass training initiative delivered predominantly by ambulance services in the UK. The aim of this study was to identify to what extent voluntary participation in the 2019 initiative delivered training to the population with the highest need.

Methods

A cross-sectional observational study of location characteristics for RSAH training events conducted by UK ambulance services. Descriptive statistics were used to analyse event and area characteristics. National cardiac arrest registry data were used to establish proportions of training coverage in “hot spot” areas with above national median incidence of cardiac arrest and below median bystander CPR rates. The significance of observed differences were tested using chi-square for proportions and t-test for means.

Results

Twelve of 14 UK ambulance services participated, training 236,318 people. Most of the events (82%) were held in schools, and schoolchildren comprised most participants (81%). RSAH events were held in areas that were less densely populated (p < 0.001), were more common in affluent areas (p < 0.001), and had a significantly lower proportion of black residents (p < 0.05) and higher proportion of white residents (p < 0.05). Events were held in 28% of known “hot spot” areas in England.

Conclusion

With mandatory CPR training for school children in England, Scotland and Wales there is an opportunity to re-focus RSAH resources to deliver training for all age groups in OHCA “hot spots”, communities with higher proportions of black residents, and areas of deprivation. In Northern Ireland, we recommend targeting schools in areas with similar characteristics.

Spatio-temporal prediction model of out-of-hospital cardiac arrest: Designation of medical priorities and estimation of human resources requirement

Aims

To determine the out-of-hospital cardiac arrest (OHCA) rates and occurrences at municipality level through a novel statistical model accounting for temporal and spatial heterogeneity, space-time interactions and demographic features. We also aimed to predict OHCAs rates and number at municipality level for the upcoming years estimating the related resources requirement.

Methods

All the consecutive OHCAs of presumed cardiac origin occurred from 2005 until 2018 in Canton Ticino region were included. We implemented an Integrated Nested Laplace Approximation statistical method for estimation and prediction of municipality OHCA rates, number of events and related uncertainties, using age and sex municipality compositions. Comparisons between predicted and real OHCA maps validated our model, whilst comparisons between estimated OHCA rates in different yeas and municipalities identified significantly different OHCA rates over space and time. Longer-time predicted OHCA maps provided Bayesian predictions of OHCA coverages in varying stressful conditions.

Results

2344 OHCAs were analyzed. OHCA incidence either progressively reduced or continuously increased over time in 6.8% of municipalities despite an overall stable spatio-temporal distribution of OHCAs. The predicted number of OHCAs accounts for 89% (2017) and 90% (2018) of the yearly variability of observed OHCAs with prediction error ≤1OHCA for each year in most municipalities. An increase in OHCAs number with a decline in the Automatic External Defibrillator availability per OHCA at region was estimated.

Conclusions

Our method enables prediction of OHCA risk at municipality level with high accuracy, providing a novel approach to estimate resource allocation and anticipate gaps in demand in upcoming years.

Attitudes to Cardiopulmonary Resuscitation and Defibrillator Use: A Survey of UK Adults in 2017

Background

Bystander cardiopulmonary resuscitation (CPR) and public access defibrillator (PAD) use can save the lives of people who experience out‐of‐hospital cardiac arrest. Little is known about the proportions of UK adults trained, their characteristics and willingness to act if witnessing an out‐of‐hospital cardiac arrest, or the public's knowledge regarding where the nearest PAD is located.

Methods and Results

An online survey was administered by YouGov to a nonprobabilistic purposive sample of UK adults, achieving 2084 participants, from a panel that was matched to be representative of the population. We used descriptive statistics and multivariate logistic regression modeling for analysis. Almost 52% were women, 61% were aged <55 years, and 19% had witnessed an out‐of‐hospital cardiac arrest. Proportions ever trained were 57% in chest‐compression‐only CPR, 59% in CPR, and 19.4% in PAD use. Most with training in any resuscitation technique had trained at work (54.7%). Compared with people not trained, those trained in PAD use said they were more likely to use one (odds ratio: 2.61), and those trained in CPR or chest‐compression‐only CPR were more likely to perform it (odds ratio: 5.39). Characteristics associated with being trained in any resuscitation technique included youth, female sex, higher social grade, and full‐time employment.

Conclusions

In the United Kingdom, training makes a difference in people's willingness to act in the event of a cardiac arrest. Although there is considerable opportunity to increase the proportion of the general population trained in CPR, consideration should be also given to encouraging training in PAD use and targeting training for those who are older or from lower social grades.

Evaluation of the reliability, utility, and quality of the information in cardiopulmonary resuscitation videos shared on Open access video sharing platform YouTube

BACKGROUND

The internet is a widely used source for obtaining medical information both by patients and physicians. YouTube is an essential source of information that may be a useful tool to inform the public and may improve the learning experience if used adequately. In this study, we aimed to estimate the quality and accuracy of videos about cardiopulmonary resuscitation videos aired on YouTube, which is the most popular video platform of the online world.

METHODS

We included the first 100 videos, in English, returned by the YouTube search engine in response to "cardiopulmonary resuscitation" keyword query to the study. The popularity of the videos was evaluated with an index called the video power index. The educational quality, accuracy, and transparency of the visual content were measured using the DISCERN questionnaire (DISCERN), Journal of American Medical Association (JAMA-BC) benchmark criteria, and Global Quality Score (GQS). The technical quality was measured by the Cardiopulmonary Resuscitation Scoring System (CPR-SS), which was utilized by three bariatric surgeons.

RESULTS

The source in 7% of the videos was medical doctors. The content in 89% of the videos was cardiopulmonary resuscitation technique. According to sources, videos uploaded by physicians had significantly higher quality, transparency, educational and technical value. Unlike, videos uploaded by physicians had a lower video power index than videos uploaded by non-medical professionals. Cardiopulmonary resuscitation technique videos had significantly higher quality, transparency, educational and technical value. Cardiopulmonary resuscitation technique videos also had higher popularity scores than "information or lecture" videos. Also, negative correlations were found between the (popularity index and transparency, education and technical quality scores.

CONCLUSIONS

Online information on cardiopulmonary resuscitation is of low quality, and its contents are of unknown source and accuracy. However, the educational potential of the online video platform, YouTube, cannot be neglected.

A Bayesian spatiotemporal statistical analysis of out-of-hospital cardiac arrests

We propose a Bayesian spatiotemporal statistical model for predicting out-of-hospital cardiac arrests (OHCAs). Risk maps for Ticino, adjusted for demographic covariates, are built for explaining and forecasting the spatial distribution of OHCAs and their temporal dynamics. The occurrence intensity of the OHCA event in each area of interest, and the cardiac risk-based clustering of municipalities are efficiently estimated, through a statistical model that decomposes OHCA intensity into overall intensity, demographic fixed effects, spatially structured and unstructured random effects, time polynomial dependence, and spatiotemporal random effect. In the studied geography, time evolution and dependence on demographic features are robust over different categories of OHCAs, but with variability in their spatial and spatiotemporal structure. Two main OHCA incidence-based clusters of municipalities are identified.

Characteristics of neighbourhoods with high incidence of out-of-hospital cardiac arrest and low bystander cardiopulmonary resuscitation rates in England

Aims

The aim of the project was to identify the neighbourhood characteristics of areas in England where out-of-hospital cardiac arrest (OHCA) incidence was high and bystander cardiopulmonary resuscitation (BCPR) was low using registry data.

Methods and results

Analysis was based on 67 219 cardiac arrest events between 1 April 2013 and 31 December 2015. Arrest locations were geocoded to give latitude/longitude. Postcode district was chosen as the proxy for neighbourhood. High-risk neighbourhoods, where OHCA incidence based on residential population was >127.6/100 000, or based on workday population was >130/100 000, and BCPR in bystander witnessed arrest was <60% were observed to have: a greater mean residential population density, a lower workday population density, a lower rural-urban index, a higher proportion of people in routine occupations and lower proportion in managerial occupations, a greater proportion of population from ethnic minorities, a greater proportion of people not born in UK, and greater level of deprivation. High-risk areas were observed in the North-East, Yorkshire, South-East, and Birmingham.

Conclusion

The study identified neighbourhood characteristics of high-risk areas that experience a high incidence of OHCA and low bystander resuscitation rate that could be targeted for programmes of training in cardiopulmonary resuscitation and automated external defibrillator use.

Identifying barriers to the provision of bystander cardiopulmonary resuscitation (CPR) in high-risk regions: A qualitative review of emergency calls

INTRODUCTION

Understanding regional variation in bystander cardiopulmonary resuscitation (CPR) is important to improving out-of-hospital cardiac arrest (OHCA) survival. In this study we aimed to identify barriers to providing bystander CPR in regions with low rates of bystander CPR and where OHCA was recognised in the emergency call.

METHODS

We retrospectively reviewed emergency calls for adults in regions of low bystander CPR in the Australian state of Victoria. Included calls were those where OHCA was identified during the call but no bystander CPR was given. A thematic content analysis was independently conducted by two investigators.

RESULTS

Saturation of themes was reached after listening to 139 calls. Calls progressed to the point of compression instructions before EMS arrival in only 26 (18.7%) of cases. Three types of barriers were identified: procedural barriers (time lost due to language barriers and communication issues; telephone problems), CPR knowledge (skill deficits; perceived benefit) and personal factors (physical frailty or disability; patient position; emotional factors).

CONCLUSION

A range of factors are associated with barriers to delivering bystander CPR even in the presence of dispatcher instructions - some of which are modifiable. To overcome these barriers in high-risk regions, targeted public education needs to provide information about what occurs in an emergency call, how to recognise an OHCA and to improve CPR knowledge and skills.

Out-of-hospital cardiac arrest in the home: Can area characteristics identify at-risk communities in the Republic of Ireland?

Background

Internationally, the majority of out-of-hospital cardiac arrests where resuscitation is attempted (OHCAs) occur in private residential locations i.e. at home. The prospect of survival for this patient group is universally dismal. Understanding of the area-level factors that affect the incidence of OHCA at home may help national health planners when implementing community resuscitation training and services.

Methods

We performed spatial smoothing using Bayesian conditional autoregression on case data from the Irish OHCA register. We further corrected for correlated findings using area level variables extracted and constructed for national census data.

Results

We found that increasing deprivation was associated with increased case incidence. The methodology used also enabled us to identify specific areas with higher than expected case incidence.

Conclusions

Our study demonstrates novel use of Bayesian conditional autoregression in quantifying area level risk of a health event with high mortality across an entire country with a diverse settlement pattern. It adds to the evidence that the likelihood of OHCA resuscitation events is associated with greater deprivation and suggests that area deprivation should be considered when planning resuscitation services. Finally, our study demonstrates the utility of Bayesian conditional autoregression as a methodological approach that could be applied in any country using registry data and area level census data.

Electronic supplementary material

The online version of this article (10.1186/s12942-018-0126-z) contains supplementary material, which is available to authorized users.

The Effect of Rurality on Out-of-Hospital Cardiac Arrest Resuscitation Incidence: An Exploratory Study of a National Registry Utilizing a Categorical Approach

PURPOSE

Variation in incidence is a universal feature of out-of-hospital cardiac arrest (OHCA). One potential source of variation is the rurality of the location where the OHCA incident occurs. While previous work has used a simple binary approach to define rurality, the purpose of this study was to use a categorical approach to quantify the impact of urban-rural classification on OHCA incidence in the Republic of Ireland.

METHODS

The observed versus expected ratio of OHCA incidence where resuscitation was attempted for the period January 1, 2012, to December 31, 2014, was calculated for each of the 3,408 electoral divisions (ED). EDs were then classified into 1 of 6 urban-rural classes. Multilevel modeling was used to test for variation in incidence ratios (IR) across the urban-rural classes.

FINDINGS

A total of 4,755 cases of adult OHCA, not witnessed by Emergency Medical Services, where resuscitation was attempted were included in the study. The number of EDs in each category was as follows: city (n = 477); town (n = 293); near village (n = 182); remote village (n = 84); near rural (n = 1,479); remote rural (n = 893). The IR per ED varied from 0 to 18.38 (EDs, n = 3,408). Multilevel modeling showed that 2.36% of variation in IR was due to urban-rural classification. This dropped to 0.45% when adjusted for ED deprivation score and median distance to an ambulance station. The addition of other explanatory variables did not improve the model.

CONCLUSION

OHCA variation in Ireland is limited and almost fully explained by area-level deprivation and proximity to ambulance stations.

Regions With Low Rates of Bystander Cardiopulmonary Resuscitation (CPR) Have Lower Rates of CPR Training in Victoria, Australia

Background

Bystander cardiopulmonary resuscitation (CPR) more than doubles the chance of surviving an out‐of‐hospital cardiac arrest. Recent data have shown considerable regional variation in bystander CPR rates across the Australian state of Victoria. This study aims to determine whether there is associated regional variation in rates of CPR training and willingness to perform CPR in these communities.

Methods and Results

We categorized each Victorian postcode as either a low or high bystander CPR region using data on adult, bystander‐witnessed, out‐of‐hospital cardiac arrests of presumed cardiac etiology (n=7175) from the Victorian Ambulance Cardiac Arrest Registry. We then surveyed adult Victorians (n=404) and compared CPR training data of the respondents from low and high bystander CPR regions. Of the 404 adults surveyed, 223 (55%) resided in regions with low bystander CPR. Compared with respondents from high bystander CPR regions, respondents residing in regions with low bystander CPR had lower rates of CPR training (62% versus 75%, P=0.009) and lower self‐ratings for their overall knowledge of CPR (76% versus 84%, P=0.04). There were no differences between the regions in their reasons for not having undergone CPR training or in their willingness to perform CPR. Rates of survival for bystander‐witnessed, out‐of‐hospital cardiac arrests were significantly lower in low bystander CPR regions (15.7% versus 17.0%, P<0.001).

Conclusions

This study found lower rates of CPR training and lower survival in regions with lower rates of bystander CPR in Victoria, Australia. Targeting these regions with CPR training programs may improve bystander CPR rates and out‐of‐hospital cardiac arrest outcomes.

Are sociodemographic characteristics associated with spatial variation in the incidence of OHCA and bystander CPR rates? A population-based observational study in Victoria, Australia

BACKGROUND

Rates of out-of-hospital cardiac arrest (OHCA) and bystander cardiopulmonary resuscitation (CPR) have been shown to vary considerably in Victoria. We examined the extent to which this variation could be explained by the sociodemographic and population health characteristics of the region.

METHODS

Using the Victorian Ambulance Cardiac Arrest Registry, we extracted OHCA cases occurring between 2011 and 2013. We restricted the calculation of bystander CPR rates to those arrests that were witnessed by a bystander. To estimate the level of variation between Victorian local government areas (LGAs), we used a two-stage modelling approach using random-effects modelling.

RESULTS

Between 2011 and 2013, there were 15 830 adult OHCA in Victoria. Incidence rates varied across the state between 41.9 to 104.0 cases/100 000 population. The proportion of the population over 65, socioeconomic status, smoking prevalence and education level were significant predictors of incidence in the multivariable model, explaining 93.9% of the variation in incidence among LGAs. Estimates of bystander CPR rates for bystander witnessed arrests varied from 62.7% to 73.2%. Only population density was a significant predictor of rates in a multivariable model, explaining 73% of the variation in the odds of receiving bystander CPR among LGAs.

CONCLUSIONS

Our results show that the regional characteristics which underlie the variation seen in rates of bystander CPR may be region specific and may require study in smaller areas. However, characteristics associated with high incidence and low bystander CPR rates can be identified and will help to target regions and inform local interventions to increase bystander CPR rates.