Cost-effectiveness of automated external defibrillator deployment in selected public locations

A resuscitation systems analysis for South Africa: A narrative review

With a growing incidence in cardiovascular diseases in Africa, including South Africa, and with it a greater incidence of out-of-hospital cardiac arrest (OHCA) there is a need to understand the readiness of these emergency care systems to support a response. Yet, OHCA is expensive and requires comprehensive development across an entire chain of survival in order to gain any benefit in mortality or morbidity. In this narrative review, we provide a resuscitation systems analysis using the Global Resuscitation Alliance's Frame of Survival. We provide evidence or commentary on the elements of the outer frame and inner frame, and make an assessment of the South African system's readiness to support OHCA care, and provide suggestions for priority areas that need to be developed. The South African resuscitation system demonstrates reasonable readiness to respond to OHCA but is characterised by considerable variation and fragmentation. Given the cost ineffectiveness of many interventions and the anticipated rise in OHCA incidence, there is a pressing need for context-specific strategies in South Africa. These strategies should focus on enhancing both outcomes and resource efficiency, while respecting community ethics and sociocultural dynamics.

Economic evaluation of automated external defibrillator deployment in public settings for out-of-hospital cardiac arrest: a systematic review

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is a major issue in aging populations. The use of automatic external defibrillators (AEDs) in public places improves cardiac arrest survival rates. The purpose of this study is to review economic evaluation studies of the use of AED technology in public settings for cardiac arrest resuscitation.

METHODS

Our search covered 1990-2021 and included PubMed, Cochrane Library, Embase, Scopus, and Web of Science. We included studies that analyzed cost-effectiveness, cost-utility and cost-benefit of the AED technology. Also, we performed the quality assessment of the studies through the checklist of quality assessment standard of health economic studies (QHES).

RESULTS

Our inclusion criteria were met by 25 studies. AEDs are found to be cost-effective in places with a high occurrence of cardiac arrest. In addition, proper integration of drones with AEDs into existing systems has the potential to significantly improve OHCA survival rates.

CONCLUSION

The present study found that putting AEDs in high-cardiac arrest and crowded areas reduces average costs. Despite this, the costs associated with acquiring and maintaining AEDs prevent their widespread use. Further research is needed to evaluate feasibility and explore innovative strategies for AED maintenance and accessibility.

The barriers and facilitators to initiation of telephone-assisted bystander cardiopulmonary resuscitation for patients experiencing out-of-hospital cardiac arrest in a private emergency dispatch centre in South Africa

Background

The incidence of cardiovascular diseases, and with it out-of-hospital cardiac arrest (OHCA), is on the increase in low- to middle-income countries (LMICs), like South Africa. Interventions such as mass public cardiopulmonary resuscitation (CPR) training campaigns and public access defibrillators are expensive and out of reach for many LMICs. Telephone-assisted CPR (tCPR) is a cost-effective, scalable alternative. This study explored the barriers and facilitators to tCPR uptake in OHCA in a private South African emergency dispatch centre.

Methods

This qualitative study applied inductive dominant content analysis to emergency call recordings of OHCA cases into a private emergency dispatch centre. Calls were analysed to the latent level to identify barriers and facilitators. Cases were sampled randomly, until data saturation.

Results

Saturation occurred after the analysis of 25 recordings. A further three recordings were analysed to confirm saturation of the facilitators; yielding a final sample size of 28 calls. Overall, t-CPR was offered in 23 (82.1%) cases, but only initiated in 8 (34.8%) of these calls. Five barriers ("Poor Communication"; "Lack of Support"; "Caller Hesitance or Uncertainty;" "Emotionality"; and "Practical Barriers") and three facilitators ("Caller Willingness"; "Support" and "CPR in Progress") were extracted.

Conclusion

Numerous barriers limit the initiation of tCPR in the South African private sector EMS. It is crucial to address these barriers and leverage the facilitators in order to improve tCPR uptake. This study highlights the importance of using specific language techniques and developing tailored tCPR algorithms to overcome these barriers, which is underpinned by standardised training of call-takers.

Cardiac Resuscitation Procedures in US Nursing Facilities: Time to Reevaluate the Standard of Care?

Although the use of automated external defibrillators (AEDs) in out-of-hospital cardiac arrest (OHCA) response has become the standard of care in many community settings over the past 20+ years, the adoption of AEDs in US nursing facilities is variable and the current number of facilities with AEDs is unknown. Recent research into the use of AEDs as part of cardiopulmonary resuscitation (CPR) procedures for nursing facility residents with sudden cardiac arrest demonstrates improved outcomes in the limited cohort with witnessed arrests, early bystander CPR, and an initial amenable rhythm, shocked with an AED before the arrival of Emergency Medical Services (EMS) personnel. This article reviews data about outcomes of CPR in older adults and nursing facility settings and proposes that standard procedures for CPR attempts in US nursing facilities should be reevaluated and continue to evolve, commensurate with the evidence and community standards.

Pediatric and adult Out-of-Hospital cardiac arrest incidence within and near public schools in British Columbia: Missed opportunities for Systematic AED deployment strategies

BACKGROUND

Systematic automated external defibrillator(AED) placement in schools may improve pediatric out-of-hospital cardiac arrest(OHCA) survival. To estimate their utility, we identified school-located pediatric and adult OHCAs to estimate the potential utilization of school-located AEDs. Further, we identified all OHCAs within an AED-retrievable distance of the school by walking, biking, and driving.

METHODS

We used prospectively collected data from the British Columbia(BC) Cardiac Arrest Registry(2013-2020), and geo-plotted all OHCAs and schools(n = 824) in BC. We identified adult and pediatric(age < 18 years) OHCAs occurring in schools, as well as nearby OHCAs for which a school-based externally-placed AED could be retrieved by a bystander prior to emergency medical system(EMS) arrival.

RESULTS

Of 16,409 OHCAs overall in the study period, 28.6 % occurred during school hours. There were 301 pediatric OHCAs. 5(1.7 %) occurred in schools, of whom 2(40 %) survived to hospital discharge. Among both children and adults, 28(0.17 %) occurred in schools(0.0042/school/year), of whom 21(75 %) received bystander resuscitation, 4(14 %) had a bystander AED applied, and 14(50 %) survived to hospital discharge. For each AED, an average of 0.29 OHCAs/year(95 % CI 0.21-0.37), 0.93 OHCAs/year(95 % CI 0.69-1.56) and 1.69 OHCAs/year(95 % CI 1.21-2.89) would be within the potential retrieval distance of a school-located AED by pedestrian, cyclist and automobile retrieval, respectively, using the median EMS response times.

CONCLUSION

While school-located OHCAs were uncommon, outcomes were favourable. 11.1% to 60.9% of all OHCAs occur within an AED-retrievable distance to a school, depending on retrieval method. Accessible external school-located AEDs may improve OHCA outcomes of school children and in the surrounding community.

Out-of-hospital cardiac arrests in the city of Cape Town metropole of the Western Cape province of South Africa: a spatio-temporal analysis

BACKGROUND

The incidence of out-of-hospital cardiac arrest (OHCA) is expected to increase in sub-Saharan Africa along with the incidence of cardiovascular disease. In low-resource settings (LRS), OHCA carries a negligible survival rate. Interventions to improve OHCA survival might not be cost effective for many LRS, and therefore need to be targeted to areas of high incidence. The aim of this study was to describe the temporal and geographic distribution of OHCA in the City of Cape Town, South Africa, and their proximity to percutaneous coronary intervention (PCI) resources.

METHODS

In this retrospective study, OHCA data between 1 January and 31 December 2018 were extracted from public and one private emergency medical services in the Western Cape. For temporal analysis, distribution of OHCA according to time of day, day of the week and month of the year were subjected to chi-squared testing. For geospatial analysis, cluster and outlier, and hotspot analyses were performed. Proximity analysis was employed to determine the driving time from OHCA location to the closest PCI-capable facility.

RESULTS

A total of 929 patients with OHCA received an emergency medical services response in the City of Cape Town, corresponding to an annual prevalence of 23.2 per 100 000 persons. The distribution of OHCA incidence was not explained by month of the year (p = 0.08) or day of the week (p = 0.67). A statistically significant variation in OHCA incidence was explained by time of day (p < 0.01) with 30% (n = 279) of all OHCAs occurring from 05:00 to 09:59. Geospatial analysis yielded a large area of hotspots (99% confidence interval) over the centre of the metropole, Cape Flats and southern suburbs. The median (interquartile range) driving time from the incident to the closest PCI-capable facility was 10:22 (08:05) minutes.

CONCLUSIONS

Incidents of OHCA occurred predominantly at home during the mid-morning, with hotspots around the city centre and residential suburbs of Cape Town. While the incidents occurred close to PCI-capable facilities, some areas remained underserved and access to PCI for OHCA victims may be impossible due to socio-economic factors. With an increase in OHCA incidence expected, it is essential that contextual, cost-effective management interventions be developed and implemented.

Utilization and cost-effectiveness of school and community center AED deployment models in Canadian cities

BACKGROUND

The optimal locations and cost-effectiveness of placing automated external defibrillators(AEDs) for out-of-hospital cardiac arrest(OHCAs) in urban residential neighbourhoods are unclear.

METHODS

We used prospectively collected data from 2016 to 2018 from the British Columbia OHCA Registry to examine the utilization and cost-effectiveness of hypothetical AED deployment in municipalities with a population of over 100 000. We geo-plotted OHCA events using seven hypothetical deployment models where AEDs were placed at the exteriors of public schools and community centers and fetched by bystanders. We calculated the "radius of effectiveness" around each AED within which it could be retrieved and applied to an individual prior to EMS arrival, comparing automobile and pedestrian-based retrieval modes. For each deployment model, we estimated the number of OHCAs within the "radius of effectiveness".

RESULTS

We included 4017 OHCAs from ten urban municipalities. The estimated radius of effectiveness around each AED was 625 m for automobile and 240m for pedestrian retrieval. With AEDs placed outside each school and community center, 2567(64%) and 605(15%) of OHCAs fell within the radii of effectiveness for automobile and pedestrian retrieval, respectively. For each AED, there was an average of 1.20-2.66 and 0.25-0.61 in-range OHCAs per year for automobile retrieval and pedestrian retrieval, respectively, depending on the deployment model. All of our proposed surpassed the cost-effectiveness threshold of 0.125 OHCA/AED/year provided >5.3-11.6% in-range AEDs were brought-to-scene.

CONCLUSIONS

The systematic deployment of AEDs at schools and community centers in urban neighbourhoods may result in increased application and be a cost-effective public health intervention.

A review on initiatives for the management of daily medical emergencies prior to the arrival of emergency medical services

Emergency services worldwide face increasing cost pressure that potentially limits their existing resources. In many countries, emergency services also face the issues of staff shortage-creating extra challenges and constraints, especially during crisis times such as the COVID-19 pandemic-as well as long distances to sparsely populated areas resulting in longer response times. To overcome these issues and potentially reduce consequences of daily (medical) emergencies, several countries, such as Sweden, Germany, and the Netherlands, have started initiatives using new types of human resources as well as equipment, which have not been part of the existing emergency systems before. These resources are employed in response to medical emergency cases if they can arrive earlier than emergency medical services (EMS). A good number of studies have investigated the use of these new types of resources in EMS systems, from medical, technical, and logistical perspectives as their study domains. Several review papers in the literature exist that focus on one or several of these new types of resources. However, to the best of our knowledge, no review paper that comprehensively considers all new types of resources in emergency medical response systems exists. We try to fill this gap by presenting a broad literature review of the studies focused on the different new types of resources, which are used prior to the arrival of EMS. Our objective is to present an application-based and methodological overview of these papers, to provide insights to this important field and to bring it to the attention of researchers as well as emergency managers and administrators.

Out-of-hospital cardiac arrests in the city of Cape Town, South Africa: a retrospective, descriptive analysis of prehospital patient records

OBJECTIVES

While prospective epidemiological data for out-of-hospital cardiac arrest (OHCA) exists in many high-income settings, there is a dearth of such data for the African continent. The aim of this study was to describe OHCA in the Cape Town metropole, South Africa.

DESIGN

Observational study with a retrospective descriptive design.

SETTING

Cape Town metropole, Western Cape province, South Africa.

PARTICIPANTS

All patients with OHCA for the period 1 January 2018-31 December 2018 were extracted from public and private emergency medical services (EMS) and described.

OUTCOME MEASURES

Description of patients with OHCA in terms of demographics, treatment and short-term outcome.

RESULTS

A total of 929 patients with OHCA received an EMS response in the Cape Town metropole, corresponding to an annual prevalence of 23.2 per 100 000 persons. Most patients were adult (n=885; 96.5%) and male (n=526; 56.6%) with a median (IQR) age of 63 (26) years. The majority of cardiac arrests occurred in private residences (n=740; 79.7%) and presented with asystole (n=322; 34.6%). EMS resuscitation was only attempted in 7.4% (n=69) of cases and return of spontaneous circulation (ROSC) occurred in 1.3% (n=13) of cases. Almost all patients (n=909; 97.8%) were declared dead on the scene.

CONCLUSION

To our knowledge, this was the largest study investigating OHCA ever undertaken in Africa. We found that while the incidence of OHCA in Cape Town was similar to the literature, resuscitation is attempted in very few patients and ROSC-rates are negligible. This may be as a consequence of protracted response times, poor patient prognosis or an underdeveloped and under-resourced Chain of Survival in low- to middle-income countries, like South Africa. The development of contextual guidelines given resources and disease burden is essential.

Strategies on locations of public access defibrillator: A systematic review

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is a critical condition with poor outcomes. Although the survival rate increases in those who undergo defibrillation, the utility of on-time defibrillation among bystanders remained low. An evaluation of the deployment strategy for public access defibrillators (PADs) is necessary to increase their use and accessibility. This study was to conduct a systematic review for deployment strategies of PADs.

METHODS

Two authors independently searched for articles published before October 2019 from PubMed, Embase, Web of Science, and Cochrane Library. An independent librarian provided the search strategy and assisted the literature research. We included articles that were focused on the main topic, but excluded those which were missing results or that used an unclear definition. The qualitative outcomes were the utility and OHCA coverage of PADs. We performed a qualitative analysis across the studies, but a quantitative analysis was not available due to the studies' heterogeneity in design and variety of outcomes.

RESULTS

We eventually included 15 studies. Three strategies were presented: guidelines-based, grid-based, and landmark-based. The guidelines-based deployment was common fit for OHCA events. The grid-based method increased the use of bystander defibrillation 3-fold, and 30-day survival doubled. The top 3 landmarks in the landmark-based strategy were offices (18.6%), schools (13.3%), and sports facilities (12.9%). Utility of PADs might increase if we optimize PAD location by mathematical modeling and evaluation feedback.

CONCLUSION

Three deployment strategies were presented. Although the optimal method could not be fully identified, a more efficient PAD deployment could benefit the population in terms of OHCA coverage and survival among patients with OHCA.

Cost-effectiveness of extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest: A multi-centre prospective cohort study

AIM

Extracorporeal cardiopulmonary resuscitation (ECPR) is an evolving resuscitative method for refractory cardiopulmonary arrests. However, considering the substantial healthcare costs and resources involved, there is an urgent need for a full economic evaluation. We therefore assessed the cost-effectiveness of ECPR for refractory ventricular fibrillation/pulseless ventricular tachycardia (VF/pVT).

METHODS

We developed a decision model to estimate lifetime costs and outcomes for out-of-hospital cardiac arrest patients with VF/pVT who received either ECPR or conventional cardiopulmonary resuscitation. Quality-adjusted life-years (QALY) was used as the main outcome measure. This model was a combination of a decision tree model for the acute phase based on a prospective observational study (SAVE-J study), together with a Markov model for long-term follow-up periods extrapolated from published data. To evaluate the robustness of this model, we conducted a comprehensive deterministic sensitivity analysis (DSA) and a probabilistic sensitivity analysis (PSA).

RESULTS

ECPR was cost-effective, with an incremental cost of ¥3,521,189 (Є30,227), an incremental effectiveness of 1.34 QALY, and an incremental cost-effectiveness ratio of ¥2,619,692 (Є22,489) per QALY gained. DSA revealed that the present model was most sensitive to probability of Cerebral Performance Category 1 after ECPR (¥2,153,977/QALY to ¥3,186,475/QALY), patient age (¥2,170,112/QALY to ¥3,334,252/QALY), and long-term medical cost for modified Rankin Scale 0 (¥2,280,352/QALY to ¥2,855,330/QALY). PSA indicated ECPR to be cost-effective and below the willingness-to-pay threshold of ¥5,000,000 with an 86.7 % possibility.

CONCLUSIONS

ECPR was an economically acceptable resuscitative strategy, and the results of the present study were robust even when considering the uncertainty of all parameters.

Effect of Optimized Versus Guidelines-Based Automated External Defibrillator Placement on Out-of-Hospital Cardiac Arrest Coverage: An In Silico Trial

Background

Mathematical optimization of automated external defibrillator (AED) placement may improve AED accessibility and out‐of‐hospital cardiac arrest (OHCA) outcomes compared with American Heart Association (AHA) and European Resuscitation Council (ERC) placement guidelines. We conducted an in silico trial (simulated prospective cohort study) comparing mathematically optimized placements with placements derived from current AHA and ERC guidelines, which recommend placement in locations where OHCAs are usually witnessed.

Methods and Results

We identified all public OHCAs of presumed cardiac cause from 2008 to 2016 in Copenhagen, Denmark. For the control, we computationally simulated placing 24/7‐accessible AEDs at every unique, public, witnessed OHCA location at monthly intervals over the study period. The intervention consisted of an equal number of simulated AEDs placements, deployed monthly, at mathematically optimized locations, using a model that analyzed historical OHCAs before that month. For each approach, we calculated the number of OHCAs in the study period that occurred within a 100‐m route distance based on Copenhagen’s road network of an available AED after it was placed (“OHCA coverage”). Estimated impact on bystander defibrillation and 30‐day survival was calculated by multivariate logistic regression. The control scenario involved 393 AEDs at historical, public, witnessed OHCA locations, covering 15.8% of the 653 public OHCAs from 2008 to 2016. The optimized locations provided significantly higher coverage (24.2%; P<0.001). Estimated bystander defibrillation and 30‐day survival rates increased from 15.6% to 18.2% (P<0.05) and from 32.6% to 34.0% (P<0.05), respectively. As a baseline, the 1573 real AEDs in Copenhagen covered 14.4% of the OHCAs.

Conclusions

Mathematical optimization can significantly improve OHCA coverage and estimated clinical outcomes compared with a guidelines‐based approach to AED placement.

Defining a Research Agenda for Layperson Prehospital Hemorrhage Control: A Consensus Statement

IMPORTANCE

Trauma is the leading cause of death for US individuals younger than 45 years, and uncontrolled hemorrhage is a major cause of trauma mortality. The US military's medical advancements in the field of prehospital hemorrhage control have reduced battlefield mortality by 44%. However, despite support from many national health care organizations, no integrated approach to research has been made regarding implementation, epidemiology, education, and logistics of prehospital hemorrhage control by layperson immediate responders in the civilian sector.

OBJECTIVE

To create a national research agenda to help guide future work for prehospital hemorrhage control by laypersons.

EVIDENCE REVIEW

The 2-day, in-person, National Stop the Bleed (STB) Research Consensus Conference was conducted on February 27 to 28, 2019, to identify and achieve consensus on research gaps. Participants included (1) subject matter experts, (2) professional society-designated leaders, (3) representatives from the federal government, and (4) representatives from private foundations. Before the conference, participants were provided a scoping review on layperson prehospital hemorrhage control. A 3-round modified Delphi consensus process was conducted to determine high-priority research questions. The top items, with median rating of 8 or more on a Likert scale of 1 to 9 points, were identified and became part of the national STB research agenda.

FINDINGS

Forty-five participants attended the conference. In round 1, participants submitted 487 research questions. After deduplication and sorting, 162 questions remained across 5 a priori-defined themes. Two subsequent rounds of rating generated consensus on 113 high-priority, 27 uncertain-priority, and 22 low-priority questions. The final prioritized research agenda included the top 24 questions, including 8 for epidemiology and effectiveness, 4 for materials, 9 for education, 2 for global health, and 1 for health policy.

CONCLUSIONS AND RELEVANCE

The National STB Research Consensus Conference identified and prioritized a national research agenda to support laypersons in reducing preventable deaths due to life-threatening hemorrhage. Investigators and funding agencies can use this agenda to guide their future work and funding priorities.

Radius of Care in Secondary Schools in the Midwest: Are Automated External Defibrillators Sufficiently Accessible to Enable Optimal Patient Care?

CONTEXT

  Sudden cardiac arrest is the leading cause of death among young athletes. According to the American Heart Association, an automated external defibrillator (AED) should be available within a 1- to 1.5-minute brisk walk from the patient for the highest chance of survival. Secondary school personnel have reported a lack of understanding about the proper number and placement of AEDs for optimal patient care.

OBJECTIVE

  To determine whether fixed AEDs were located within a 1- to 1.5-minute timeframe from any location on secondary school property (ie, radius of care).

DESIGN

  Cross-sectional study.

SETTING

  Public and private secondary schools in northwest Ohio and southeast Michigan.

PATIENTS OR OTHER PARTICIPANTS

  Thirty schools (24 public, 6 private) volunteered.

MAIN OUTCOME MEASURE(S)

  Global positioning system coordinates were used to survey the entire school properties and determine AED locations. From each AED location, the radius of care was calculated for 3 retrieval speeds: walking, jogging, and driving a utility vehicle. Data were analyzed to expose any property area that fell outside the radius of care.

RESULTS

  Public schools (37.1% ± 11.0%) possessed more property outside the radius of care than did private schools (23.8% ± 8.0%; F_1,28 = 8.35, P = .01). After accounting for retrieval speed, we still observed differences between school types when personnel would need to walk or jog to retrieve an AED ( F_1.48,41.35 = 4.99, P = .02). The percentages of school property outside the radius of care for public and private schools were 72.6% and 56.3%, respectively, when walking and 34.4% and 12.2%, respectively, when jogging. Only 4.2% of the public and none of the private schools had property outside the radius of care when driving a utility vehicle.

CONCLUSION

  Schools should strategically place AEDs to decrease the percentage of property area outside the radius of care. In some cases, placement in a centralized location that is publicly accessible may be more important than the overall number of AEDs on site.

Bystander automated external defibrillator use and clinical outcomes after out-of-hospital cardiac arrest: A systematic review and meta-analysis

AIM

To systematically review studies comparing bystander automated external defibrillator (AED) use to no AED use in regard to clinical outcomes in out-of-hospital cardiac arrest (OHCA), and to provide a descriptive summary of studies on the cost-effectiveness of bystander AED use.

METHODS

We searched Medline, Embase, the Web of Science, and the Cochrane Library for randomized trials and observational studies published before June 1, 2017. Meta-analyses were performed for patients with all rhythms, shockable rhythms, and non-shockable rhythms.

RESULTS

Forty-four observational studies, 3 randomized trials, and 13 cost-effectiveness studies were included. Meta-analysis of 6 observational studies without critical risk of bias showed that bystander AED use was associated with survival to hospital discharge (all rhythms OR: 1.73 [95%CI: 1.36, 2.18], shockable rhythms OR: 1.66 [95%CI: 1.54, 1.79]) and favorable neurological outcome (all rhythms OR: 2.12 [95%CI: 1.36, 3.29], shockable rhythms OR: 2.37 [95%CI: 1.58, 3.57]). There was no association between bystander AED use and neurological outcome for non-shockable rhythms (OR: 0.76 [95%CI: 0.10, 5.87]). The Public-Access Defibrillation trial found higher survival rates when volunteers were equipped with AEDs. The other trials found no survival difference, although their study settings differed. The quality of evidence was low for randomized trials and very low for observational studies. AEDs were cost-effective in settings with high cardiac arrest incidence, with most studies reporting ratios < $100,000 per quality-adjusted life years.

CONCLUSIONS

The evidence supports the association between bystander AED use and improved clinical outcomes, although the quality of evidence was low to very low.

Optimizing a Drone Network to Deliver Automated External Defibrillators

BACKGROUND

Public access defibrillation programs can improve survival after out-of-hospital cardiac arrest, but automated external defibrillators (AEDs) are rarely available for bystander use at the scene. Drones are an emerging technology that can deliver an AED to the scene of an out-of-hospital cardiac arrest for bystander use. We hypothesize that a drone network designed with the aid of a mathematical model combining both optimization and queuing can reduce the time to AED arrival.

METHODS

We applied our model to 53 702 out-of-hospital cardiac arrests that occurred in the 8 regions of the Toronto Regional RescuNET between January 1, 2006, and December 31, 2014. Our primary analysis quantified the drone network size required to deliver an AED 1, 2, or 3 minutes faster than historical median 911 response times for each region independently. A secondary analysis quantified the reduction in drone resources required if RescuNET was treated as a large coordinated region.

RESULTS

The region-specific analysis determined that 81 bases and 100 drones would be required to deliver an AED ahead of median 911 response times by 3 minutes. In the most urban region, the 90th percentile of the AED arrival time was reduced by 6 minutes and 43 seconds relative to historical 911 response times in the region. In the most rural region, the 90th percentile was reduced by 10 minutes and 34 seconds. A single coordinated drone network across all regions required 39.5% fewer bases and 30.0% fewer drones to achieve similar AED delivery times.

CONCLUSIONS

An optimized drone network designed with the aid of a novel mathematical model can substantially reduce the AED delivery time to an out-of-hospital cardiac arrest event.

Cost-effectiveness of a national public access defibrillation programme

AIM

Proposed Irish legislation aimed at increasing survival from out-of-hospital-cardiac-arrest (OHCA) mandates the provision of automated external defibrillators (AEDs) in a comprehensive range of publicly accessible premises in urban and rural areas. This study estimated the clinical and cost effectiveness of the legislation, compared with alternative programme configurations involving more targeted AED placement.

METHODS

We used a cost-utility analysis to estimate the costs and consequences of public access defibrillation (PAD) programmes from a societal perspective, based on AED deployment by building type. Comparator programmes ranged from those that only included building types with the highest incidence of OHCA, to the comprehensive programme outline in the proposed legislation. Data on OHCA incidence and outcomes were obtained from the Irish Out-of-Hospital-Cardiac-Arrest Register (OHCAR). Costs were obtained from the Irish health service, device suppliers and training providers.

RESULTS

The incremental cost effectiveness ratio (ICER) for the most comprehensive PAD scheme was €928,450/QALY. The ICER for the most scaled-back programme involving AED placement in transport stations, medical practices, entertainment venues, schools (excluding primary) and fitness facilities was €95,640/QALY. A 40% increase in AED utilisation when OHCAs occur in a public area could potentially render this programme cost effective.

CONCLUSION

National PAD programmes involving widespread deployment of static AEDs are unlikely to be cost-effective. To improve cost-effectiveness any prospective programmes should target locations with the highest incidence of OHCA and be supported by efforts to increase AED utilisation, such as improving public awareness, increasing CPR and AED training, and establishing an EMS-linked AED register.

Implications for public access defibrillation placement by non-traumatic out-of-hospital cardiac arrest occurrence in Singapore

INTRODUCTION

The American Heart Association recommends automated external defibrillator placement in public areas with a high probability (>1) of out-of-hospital cardiac arrest (OHCA) occurring in 5 years. We aimed to determine the incidence rate of OHCA for different location categories in Singapore.

METHODS

Cardiac arrest incidence was obtained from a national registry. Denominators for the actual number of sites per location category were obtained from public accessible sources, government officers and purchased statistics. Analysis was performed and expressed in terms of the corresponding 95% confidence interval (CI).

RESULTS

From 1 October 2001 to 14 October 2004, 2254 non-trauma OHCA cases were included. Mean age for arrests was 62.2 years, with 67.5% men. The location category with the highest incidence of cardiac arrests per site per 5 years was Port/Airport/Immigration Checkpoints (5.24 CI [3.66-7.20]). Top individual site with high average incidence of cardiac arrests per 5 years was Changi Airport (25.0 CI [16.18-36.90]). Seventy-one per cent of arrests occurred in residential areas. The postal sector with the highest average incidence per 100 000 population was Bedok Reservoir (54.89), whereas that with the highest population density was Bukit Merah/Alexandra with 348.14 population per 100 km(2) .

CONCLUSION

In this study, we found the categories and individual sites that clearly fulfilled the American Heart Association criteria of at least 1 OHCA per site per 5 years. This study provides a model of how cardiac arrest registry data can be used to guide local health policy on automated external defibrillator deployment.

Role of wearable and automatic external defibrillators in improving survival in patients at risk for sudden cardiac death

Cardiac arrest is a vexing public health problem. Fortunately, implantable cardioverter-defibrillators (ICDs) have been proven to decrease overall mortality in several populations at high risk for cardiac arrest. However, it is still unclear how to treat patients who have an elevated risk of cardiac arrest but are not in one of the identified high-risk groups proven to benefit from an ICD. It also is uncertain how to manage high-risk patients who have an accepted indication for an ICD but are unable or unwilling to have an ICD. In these clinical situations, the wearable defibrillator and automatic external defibrillator are options that should be considered. Both devices have been shown in small series to be highly effective at restoring sinus rhythm in patients with a ventricular tachyarrhythmia. However, there is still a lack of large-scale trials proving that these devices should be employed routinely in specific high-risk patient populations.

In situ simulation comparing in-hospital first responder sudden cardiac arrest resuscitation using semiautomated defibrillators and automated external defibrillators

INTRODUCTION

Multifaceted approaches using simulation and human factors methods may optimize in-hospital sudden cardiac arrest (SCA) response. The Arrhythmia Simulation/Cardiac Event Nursing Training-Automated External Defibrillator phase (ASCENT-AED) study used in situ medical simulation to compare traditional and AED-supplemented SCA first-responder models.

METHODS

The study was conducted at an academic 719-bed hospital with institutional review board approval. Two simulation scenarios were developed and featured either respiratory arrest with perfusing bradycardia or ventricular fibrillation (VF) arrest. Study floors were equipped with either a semiautomated defibrillator (SD) only (control) or with both SD and AED (experimental); subjects functioned as solitary first responders and did not receive resuscitation training.

RESULTS

Fifty nurses were enrolled on control (n=25) and experimental (n=25) floors. The groups' nonblinded performances exhibited the following differences during VF scenario: slower calls for help by the control group [mean time to completion of 25+/-17 seconds versus 18+/-11 seconds for the experimental group (P<0.05)] and fewer subjects in the control group performing chest compressions [44.0% versus experimental group's 95.8% (P<0.001)]. Eighty-eight percent of the control group defibrillated the manikin at an average of 155+/-59 seconds, with 32.0% of those subjects using semiautomated rhythm analysis; 100% (not significant [NS]) of experimental group defibrillated at 154+/-72 seconds (NS) with 100% AED analysis (P<0.001). Fewer control group subjects (28.0%) were observed during the bradycardia scenarios to perform inappropriate chest compressions than the AED-supplemented subjects [69.6% (P=0.01)]; nonindicated defibrillation was delivered during these scenarios by a single subject in the control group. Twenty-eight percent and 72% of VF scenarios were managed appropriately by control and experimental groups, respectively; bradycardia scenarios were managed without severe adverse event by 64% of control group and 28% of experimental group.

CONCLUSIONS

In situ simulation can provide useful information, both anticipated and unexpected, to guide decisions about proposed defibrillation technologies and SCA response models for in-hospital resuscitation system design and education before implementation.

Realistic expectations for public access defibrillation programs

PURPOSE OF REVIEW

Public access defibrillation programs have increased dramatically over the past 15 years. This review will focus on their effectiveness and operational characteristics and discuss the characteristics of successful programs, which can improve outcomes.

RECENT FINDINGS

Automated external defibrillators increase survival from cardiac arrest when used by a bystander. Recent studies show that the best outcomes are achieved when devices are placed in areas with a high frequency of cardiac arrest and there is ongoing supervision with emergency plans and cardiopulmonary resuscitation training. Programs are cost-effective under these circumstances, but become very inefficient when placed in areas of low risk. There are few adverse events related to the public access defibrillation programs and volunteers are not harmed. Unguided placement results in devices not being used and a decline in organizational structure of the program. As most cardiac arrests occur in the home, the impact on overall survival remains low.

SUMMARY

Automated external defibrillators are highly effective at reducing death from ventricular fibrillation and easy access in public areas is most effective. Placement must be prioritized based on public health impact and characteristics of the community.

Differences between out-of-hospital cardiac arrest in residential and public locations and implications for public-access defibrillation

BACKGROUND

The majority of out-of-hospital cardiac arrests (OHCAs) occur in residential locations, but knowledge about strategic placement of automated external defibrillators in residential areas is lacking. We examined whether residential OHCA areas suitable for placement of automated external defibrillators could be identified on the basis of demographic characteristics and characterized individuals with OHCA in residential locations.

METHODS AND RESULTS

We studied 4828 OHCAs in Copenhagen between 1994 and 2005. The incidence and characteristics of OHCA were examined in every 100 x 100-m (109.4 x 109.4-yd) residential area according to its underlying demographic characteristics. By combining > or =2 demographic characteristics, it was possible to identify 100 x 100-m (109.4 x 109.4-yd) areas with at least 1 arrest every 5.6 years (characterized by >300 persons per area and lowest income) to 1 arrest every 4.3 years (characterized by >300 persons per area, lowest income, low education, and highest age). These areas covered 9.0% and 0.8% of all residential OHCAs, respectively. Individuals with OHCA in residential locations differed from public ones in that the patients were older (70.6 versus 60.6 years; P<0.0001), the ambulance response interval was longer (6.0 versus 5.0 minutes; P<0.0001), arrests occurred more often at night (21.2% versus 11.2%; P<0.0001), the patients had ventricular fibrillation less often (12.8% versus 38.1%; P<0.0001), and the patients had a worse 30-day survival rate (3.2% versus 13.9%; P<0.0001).

CONCLUSIONS

On the basis of simple demographic characteristics of a city center, we could identify residential areas suitable for automated external defibrillator placement. Individuals with OHCA in residential locations were more likely to have characteristics associated with poor outcome compared with public arrests.

Cardiac deatH prevention by aUtomated defibrillatoRs in ChurcHes: rationale and design of the CHURCH trial

Early defibrillation programs by the use of automated external defibrillators (AEDs) located in high-attendance public places may improve survival and neurologic outcome of patients undergoing sudden cardiac arrest (SCA). We planned a prospective cohort study to assess the effectiveness of a public-access defibrillation program based on positioning of AEDs in churches and training of lay volunteers in Basic Life Support Defibrillation during a single-day 5-hour training session. The CHURCH project aims to promote a widespread diffusion of AEDs, to train a large number of lay volunteers in Basic Life Support Defibrillation, and to increase population awareness on the opportunities for sudden death prevention. The rationale of the study rests on a survey commissioned by the Diocese of Milan that found a high prevalence of elderly subjects (44.5% were >60 years old) attending holy services in the morning hours, when sudden death incidence peaks. The catchment areas of the 12 parishes included in the trial as of June 2008 include a population of 140,000. The projected incidence of AED-treatable SCA, based on the presence of trained volunteers in the churches during day hours, at the CHURCH participating sites was estimated at 8 episodes per year. To estimate an overall 30% mortality reduction from SCA after AED placement at the study sites with respect to conventional SCA management by the Emergency Medical Service, 25 SCA episodes will have to be treated during the 4-year study period. The CHURCH project might be of interest and applicable in every country where high-attendance worship places are present.

Public Access Defibrillation

In the United States, 250,000 people die from a cardiac arrest every year. Despite a well established emergency medical response system, survival from out-of-hospital cardiac arrest remains poor in United States cities. Paramount to achieving successful resuscitation of a cardiac arrest victim is provision of early defibrillation. Among patients that arrest due to a ventricular fibrillation, the likelihood of survival decreases by 10% for every minute of delay in defibrillation. In 1995, the American Heart Association challenged the medical industry to develop a defibrillator that could be placed in public settings, used safely by lay responders, and provide earlier defibrillation to cardiac arrest victims. Over the last decade, there have been significant technological advancements in automated external defibrillators (AEDs), and clinical studies have demonstrated their benefits and limitations in various public locations. This article discusses the technologic features of the modern AED and the current data available on the use of AEDs in public settings.

Location of cardiac arrest in a city center: strategic placement of automated external defibrillators in public locations

BACKGROUND

Public-access defibrillation with automated external defibrillators (AEDs) is being implemented in many countries worldwide with considerable financial implications. The potential benefit and economic consequences of focused or unfocused AED deployment are unknown.

METHODS AND RESULTS

All cardiac arrests in public in Copenhagen, Denmark, from 1994 through 2005 were geographically located, as were 104 public AEDs placed by local initiatives. In accordance with European Resuscitation Council and American Heart Association (AHA) guidelines, areas with a high incidence of cardiac arrests were defined as those with 1 cardiac arrest every 2 or 5 years, respectively. There were 1274 cardiac arrests in public locations. According to the European Resuscitation Council or AHA guidelines, AEDs needed to be deployed in 1.2% and 10.6% of the city area, providing coverage for 19.5% (n=249) and 66.8% (n=851) of all cardiac arrests, respectively. The excessive cost of such AED deployments was estimated to be $33 100 or $41 000 per additional quality-adjusted life year, whereas unguided AED placement covering the entire city had an estimated cost of $108 700 per quality-adjusted life year. Areas with major train stations (1.8 arrests every 5 years per area), large public squares, and pedestrianized areas (0.6 arrests every 5 years per area) were main predictors of frequent cardiac arrests.

CONCLUSIONS

To achieve wide AED coverage, AEDs need to be more widely distributed than recommended by the European Resuscitation Council guidelines but consistent with the American Heart Association guidelines. Strategic placement of AEDs is pivotal for public-access defibrillation, whereas with unguided initiatives, AEDs are likely to be placed inappropriately.

Location of Cardiac Arrests in the Public Access Defibrillation Trial

BACKGROUND

The Public Access Defibrillation (PAD) Trial found an overall doubling in the number of out-of-hospital cardiac arrest (CA) survivors when a lay responder team was equipped with an automated external defibrillator (AED), compared with cardiopulmonary resuscitation (CPR) alone.

OBJECTIVES

To describe the types of facilities that participated in the trial and to report the incidence of CA and survival in these different types of facilities.

METHODS

In this post-hoc analysis of PAD Trial data, the physical characteristics of the participating facilities and the numbers of presumed CAs, treatable CAs, and survivors are reported for each category of facilities.

RESULTS

There were 625 presumed CAs at 1,260 participating facilities. Just under half (n = 291) of the presumed CAs were classified as treatable CAs. Treatable CAs occurred at a rate of 2.9 per 1,000 person-years of exposure; rates were highest in fitness centers (5.1) and golf courses (4.8) and lowest in office complexes (0.7) and hotels (0.7). Survival from treatable CA was highest in recreational complexes (0.5), public transportation sites (0.4), and fitness centers (0.4) and lowest in office complexes (0.1) and residential facilities (0.0).

CONCLUSIONS

During the PAD Trial, the exposure-adjusted rate of treatable CA was highest in fitness centers and golf courses, but the incidence per facility was low to moderate. Survival from treatable cardiac arrest was highest in recreational complexes, public transportation facilities, and fitness centers.

Validation of a Predictive Model for Automated External Defibrillator Placement in Rural America

OBJECTIVE

The development of Automated External Defibrillators (AEDs) to treat out-of-hospital cardiac arrest (OOHCA) has greatly expanded the availability of life saving defibrillatory shocks in various settings. However, placement of AEDs in rural areas remains perplexing since OOHCAs are rare and unpredictable. We set out to develop a cost-effective rural AED placement model and to test the validity of the resulting model using OOHCAs attended by EMS.

METHODS

DESIGN

A population-based cross-sectional study. Analytic Plan: An exhaustive literature search was conducted to identify community attributes correlated with successful placement of AEDs in rural regions. Identified attributes were characterized using U.S. Census and CDC heart disease mortality data to estimate the potential risk for AED use and applied this estimate to rural census tracts in all 50 states. Based upon risk, AEDS were assigned to each tract using a first responder model and cost effectiveness was assessed. Using Utah State EMS data, the predicted placement of AEDs in each tract was validated using the actual number of OOHCAs attended by EMS.

RESULTS

A total of 14,586 rural census tracts in 50 U.S. states were evaluated. On average, 2,600 AEDs were situated within each state. AED placement in rural areas proved as cost effective as health screening programs. In Utah, predicted AED placement correlated with the frequency of OOHCAs attended by EMS personnel (rho= 0.55, p < 0.001).

CONCLUSIONS

The resulting model illustrates one potential way to determine the most beneficial location for rural AED placement.

Community public access sites: compliance with American Heart Association recommendations

BACKGROUND

Public access defibrillation (PAD) programs are a major goal of the American Heart Association (AHA) to ensure that automated external defibrillators and trained lay rescuers are available in public areas where sudden cardiac arrest (SCA) is likely to occur. The Johnson County Early Defibrillation Task Force (JCEDTF) is a volunteer organization which distributed AEDs throughout Johnson County, Iowa. JCEDTF was responsible for initial training but ongoing support was the responsibility of each site.

OBJECTIVE

The purpose of this study was to evaluate compliance of community PAD sites to recommendations for site maintenance as proposed by the American Heart Association (AHA).

METHODS

Thirty-two surveys were distributed to community PAD sites that received assistance from JCEDTF. PAD sites were categorized into business, educational, or community sites. A twenty-five point scoring system to assess PDA programs was developed based on AHA recommendations. On-site evaluations were conducted to verify survey results and assess barriers to an effective PAD site. Differences among the three categories were measured with ANOVA.

RESULTS

No site was able to comply with all the AHA guidelines for a PAD site. The mean score among all sites was 57% of possible points with no significant differences among the three categories. Business sites were more compliant with ongoing training compared to educational and community sites (p<0.022).

CONCLUSIONS

Community PAD sites in Johnson County currently do not comply with the recommendations for effective PAD sites. After initial training and establishment of community PAD sites, better methods for assuring ongoing training and maintenance are needed for sites to be effective.

Measuring the value of public health systems: the disconnect between health economists and public health practitioners

We investigated ways of defining and measuring the value of services provided by governmental public health systems. Our data sources included literature syntheses and qualitative interviews of public health professionals. Our examination of the health economic literature revealed growing attempts to measure value of public health services explicitly, but few studies have addressed systems or infrastructure. Interview responses demonstrated no consensus on metrics and no connection to the academic literature. Key challenges for practitioners include developing rigorous, data-driven methods and skilled staff; being politically willing to base allocation decisions on economic evaluation; and developing metrics to capture "intangibles" (e.g., social justice and reassurance value). Academic researchers evaluating the economics of public health investments should increase focus on the working needs of public health professionals.

An observational study describing the geographic-time distribution of cardiac arrests in Singapore: what is the utility of geographic information systems for planning public access defibrillation? (PADS Phase I)

INTRODUCTION

Public access defibrillation (PAD) has shown potential to increase cardiac arrest survival rates.

OBJECTIVES

To describe the geographic epidemiology of prehospital cardiac arrest in Singapore using geographic information systems (GIS) technology and assess the potential for deployment of a PAD program.

METHODS

We conducted an observational prospective study looking at the geographic location of pre-hospital cardiac arrests in Singapore. Included were all patients with out-of-hospital cardiac arrest (OHCA) presented to emergency departments. Patient characteristics, cardiac arrest circumstances, emergency medical service (EMS) response and outcomes were recorded according to the Utstein style. Location of cardiac arrests was spot-mapped using GIS.

RESULTS

From 1 October 2001 to 14 October 2004, 2428 patients were enrolled into the study. Mean age for arrests was 60.6 years with 68.0% male. 67.8% of arrests occurred in residences, with 54.5% bystander witnessed and another 10.5% EMS witnessed. Mean EMS response time was 9.6 min with 21.7% receiving prehospital defibrillation. Cardiac arrest occurrence was highest in the suburban town centers in the Eastern and Southern part of the country. We also identified communities with the highest arrest rates. About twice as many arrests occurred during the day (07:00-18:59 h) compared to night (19:00-06:59 h). The categories with the highest frequencies of occurrence included residential areas, in vehicles, healthcare facilities, along roads, shopping areas and offices/industrial areas.

CONCLUSION

We found a definite geographical distribution pattern of cardiac arrest. This study demonstrates the utility of GIS with a national cardiac arrest database and has implications for implementing a PAD program, targeted CPR training, AED placement and ambulance deployment.

Cardiac Arrest in Schools

BACKGROUND

The purpose of the present study is to improve understanding of the epidemiology of cardiac arrest in the school setting, with a special focus on the role of school-based automated external defibrillators.

METHODS AND RESULTS

The investigation was a retrospective study of emergency medical service-treated, nontraumatic, out-of-hospital cardiac arrests in Seattle and King County, Washington, that occurred in schools between 1990 and 2005. Cases were identified with cardiac arrest location data from emergency medical service cardiac arrest registries. Patient characteristics, cardiac arrest characteristics, and outcome information were abstracted from the registries and incident report forms. During the study period, 97 cardiac arrests occurred in schools, accounting for 0.4% of all treated cardiac arrests and 2.6% of public location cardiac arrests. Of the 97 cases, 12 cardiac arrests were among students, 33 among faculty and staff, and 45 among adults not employed by the school (7 adults with indeterminate school association). School-based cardiac arrest occurred on average in 1 of 111 schools annually, with a greater annual incidence among colleges (1 cardiac arrest per 8 colleges) than high schools (1 per 125 high schools) or lower-level schools (1 cardiac arrest per 200 preschools through middle schools). The estimated annual incidence of cardiac arrest was 0.18 per 100,000 person-years among students and 4.51 per 100,000 person-years for school faculty and staff.

CONCLUSIONS

The present study characterizes school-setting cardiac arrest and provides a framework within which to consider preparation efforts and outcome expectations.

Assessing automated external defibrillators in preventing deaths from sudden cardiac arrest: An economic evaluation

Objectives:The aim of this study was to evaluate the cost-effectiveness of on-site automated external defibrillators (AEDs) in the initial management of cardiac arrest in Ontario.

Methods:This was a cost-effectiveness analysis based on published literature and data from the Canadian Institute of Health Information. The participants were fictitious male and female cardiac arrest patients who were initially managed with on-site AEDs, compared with similar patients managed without on-site AEDs. This group included a subgroup of high-risk patients (i.e., heart failure and left ventricular ejection fraction <35 percent). The analysis was conducted in a variety of settings including hospitals and homes in Ontario, Canada. The main outcome evaluated was cost per quality-adjusted life-year (QALY) gained from a payer's perspective.

Results:Cost per QALY (all costs reported in Canadian dollars) was $12,768 when AEDs were deployed in hospitals, $511,766 when deployed in office buildings, $2,360,023 when deployed in apartment buildings, $87,569 when deployed in homes of high-risk patients, and $1,529,371 when deployed in homes of people older than 55 years of age.

Conclusions:Indiscriminate deployment of AEDs is not a cost-effective means of improving health outcomes of cardiac arrest. Their use should be restricted to emergency response programs, high-risk sites (such as hospitals), and high-risk patients.

Cost-effectiveness of automated external defibrillators in public places: pro

PURPOSE OF REVIEW

Placement of automated external defibrillators in public facilities is a cost-effective treatment for out-of-hospital cardiac arrests. This review describes the literature citing the benefits of early defibrillation, ease of use, and relative cost of automated external defibrillators.

RECENT FINDINGS

Placement of automated external defibrillators in public places was recommended by the American Heart Association in the early 1990s. Compared with waiting for traditional emergency medical services, immediate use of automated external defibrillators by laypersons can dramatically increase survival to hospital discharge rates. Placement of automated external defibrillators at locations such as casinos, airports, and airplanes that are frequented by large numbers of at-risk people is cost-effective compared with other economically acceptable health measures. Studies using simulations to predict numbers of quality-adjusted life years that would be gained from implementation of public access defibrillation programs in high-incidence locations find that the cost would be less than the typically acceptable 50,000 dollars per quality-adjusted life year. The cost estimates, however, depend on the incidence of cardiac arrest at the sites, with low-incidence sites being prohibitively expensive.

SUMMARY

Automated external defibrillators appear to be cost-effective in locations with high incidences of cardiac arrest.

Reaching the public via a multi media campaign as a first step to nationwide public access defibrillation

Public access defibrillation (PAD) is a promising strategy to fight sudden cardiac death. The Austrian Red Cross provided automated external defibrillators (AEDs) and basic life support (BLS) training as an "all inclusive package" combined with on site consultation and maintenance with annual retraining as a part of a nationwide PAD programme. A multi media campaign was started to promote the package and to increase awareness about sudden cardiac death. Data about the campaign, its recognition by the public in Austria and the number of packages were recorded. Sixty-eight percent of the Austrian public above the age of 15 years were able to recall the multi media campaign. Comparing the periods before and after the campaign, the number of website hits climbed significantly from 2,931 hits/month (1,866-6,168) to 4,812 hits/month (3,432-13,434) (p=0.0276). The number of AED services implemented before the campaign increased significantly (p=0.0026) in the time after the campaign. Therefore, we conclude that a multi media campaign is useful to stimulate public discussion and it encourages companies to buy "all inclusive packages" containing AEDs, BLS training, on site consultation and maintenance. These measures represent a possible first step in introducing PAD but it seems that they have to be continued on a constant basis.

Future shock: automatic external defibrillators

PURPOSE OF REVIEW

This review provides a practical overview of the performance capabilities of automatic external defibrillators (AEDs), and of advances in technology and dissemination programmes for these devices.

RECENT FINDINGS

Arrhythmia analysis by AEDs is extremely reliable in most settings (sensitivity 81-100%, specificity 99.9-97.6%). Accurate detection of arrhythmias has also been demonstrated in children, leading the US Food and Drug Administration to approve the use of several AEDs in children aged 8 years or younger. Factors that potentially may reduce the quality of arrhythmia detection are the presence of wide complex supraventricular tachycardia and location of an arrythmic event near to high-power lines. AED use by professional basic life support providers resulted in increased survival in the prehospital setting. However, provision of AEDs to nonmedical rescue services did not result in universal improvement in patient outcome. Public access defibrillation programmes have led to higher rates of survival from cardiac arrest. The role of AEDs in hospitals has yet to be elucidated, although in-hospital mortality from ventricular arrhythmias has been shown to decrease following AED deployment.

SUMMARY

Given the correct setting, AEDs can ensure that defibrillation is not limited by lack of medical knowledge or difficulties in decision making. However, event-related variables and operator-related factors, that are yet to be determined, can significantly affect the efficacy of automatic external defibrillation.

Use of automated external defibrillators at NCAA Division I universities

PURPOSE

The placement of automated external defibrillators (AED) at public sporting events is a growing national trend. The purpose of the present study was to investigate the prevalence, past use, and cost of implementing AED at university sporting venues.

METHODS

Questionnaires were sent to the head athletic trainer at all Division I NCAA universities (N = 326) and responses collected between August and November 2003.

RESULTS

Completed surveys were returned by 244 institutions (75% response rate). Ninety-one percent (221/244) had AED for an average of 3.3 yr (range 1-13) with a median of four AED per institution (range 1-30). There were 35 cases of AED use for sudden cardiac arrest with 77% (27/35) occurring in older nonstudents, 14% (5/35) in intercollegiate athletes, and 3% (1/35) in a student nonintercollegiate athlete (information unavailable in two cases). The immediate resuscitation rate was 54% (19/35). A shock was delivered in 21 cases with a resuscitation rate of 71% (15/21). None of the intercollegiate athletes were successfully resuscitated. The average cost per AED was 2460 US dollars. In a 10-yr model (expected useful life of an AED), the cost per life immediately resuscitated was 52,400 US dollars, and the estimated cost per life-year gained ranged 10,500 US dollars to 22,500 US dollars.

CONCLUSIONS

Most Division I universities have AED available at selected sporting venues. Although no benefit was demonstrated for intercollegiate athletes, AED were successfully used in older nonstudents with cardiac arrest with a favorable long-term cost analysis.

Automated external defibrillator deployment in high schools and senior centers

BACKGROUND

Policymakers with limited funds have been forced to make difficult decisions regarding which sites merit automated external defibrillators (AEDs). Guidelines have recommended that the allocation of AEDs be based largely on the site-specific risk of sudden cardiac death (cardiac arrest), with devices preferentially located at high-risk venues. However, there are limited data on whether such a strategy is being followed. The authors surveyed low-risk (schools) and high-risk (senior centers) venues to assess the availability of AEDs.

METHODS

A random sample of 200 high schools was identified; 12 were excluded, resulting in a final sample of 188. Each was contacted to determine the number of students, number of teachers, availability of AEDs, and number of cardiac arrests during the 2001-02 academic year. For comparison, 20 licensed senior centers were surveyed to assess the availability of AEDs.

RESULTS

Among 147 schools that responded to the survey, the mean student enrollment was 1,117 and the mean number of teachers was 58. There were three reported cases of cardiac arrest (2 students, 1 teacher), resulting in an annual incidence of cardiac arrest in a school of 2.1% (95% confidence interval [CI] 0.4%-5.7%). Thirty-seven schools (25%; 95% CI 18%-33%) reported having AEDs and 35 (27%) intended to purchase them. In contrast, among 20 senior centers, AEDs were available at two (10%; 95% CI 1%-32%), and the and there were four reported cardiac arrests (annual incidence 20%).

CONCLUSION

The availability of AEDs across different sites may not correspond directly to the risk of cardiac arrest at these sites.

Use of automated external defibrillators in cardiac arrest: an evidence-based analysis

OBJECTIVE

The objectives were to identify the components of a program to deliver early defibrillation that optimizes the effectiveness of automated external defibrillators (AEDs) in out-of-hospital and hospital settings, to determine whether AEDs are cost-effective, and if cost-effectiveness was determined, to advise on how they should be distributed in Ontario.

CLINICAL NEED

Survival in people who have had a cardiac arrest is low, especially in out-of-hospital settings. With each minute delay in defibrillation from the onset of cardiac arrest, the probability of survival decreases by 10%. (1) Early defibrillation (within 8 minutes of a cardiac arrest) has been shown to improve survival outcomes in these patients. However, in out-of-hospital settings and in certain areas within a hospital, trained personnel and their equipment may not be available within 8 minutes. This implies that "first responders" should take up the responsibility of delivering shock. The first responders in out-of-hospital settings are usually bystanders, firefighters, police, and community volunteers. In hospital settings, they are usually nurses. These first responders are not trained in reading electrocardiograms and identifying abnormal heart rhythms restorable by defibrillation.

THE TECHNOLOGY

An AED is a device that can analyze a heart rhythm and deliver a shock if needed. Thus, AEDs can be used by first responders to deliver early defibrillation in out-of-hospital and hospital settings. However, simply providing an AED would not likely improve survival outcomes. Rather, AEDs have a role in strengthening the "chain of survival," which includes prompt activation of the 911 telephone system, early cardiopulmonary resuscitation (CPR), rapid defibrillation, and timely advanced life support. In the chain of survival, the first step for a witness of a cardiac arrest in an out-of-hospital setting is to call 911. Second, the witness initiates CPR (if she or he is trained in CPR). If the witness cannot initiate CPR, or the first responders of the 911 system (e.g., firefighters/police) have arrived, the first responders initiate CPR. Third, the witness or first responders apply an AED to the patient. The device reads the patient's heart rhythm and prompts for shock when indicated. Fourth, the patient is handed over to the advanced life-support team with subsequent admission to an intensive care unit in a hospital. The use of AEDs requires developing and implementing a program at sites where the cardiac arrest rate is high, where a number of potential first responders are trained and retained, and where patients are transferred to an advanced care facility after initiating resuscitation. Obviously, placing an AED at a site where no cardiac arrests are likely to occur would be futile, as would placing an AED at a site where no one knows how to use it. Moreover, abandoning patients after initial resuscitation by not transferring them to an advanced care facility would negate all earlier efforts. Thus, it is important to identify the essential components of an AED program that might also optimize the effectiveness of AED use.

METHODS

There is a large body of literature on the use of AEDs in various settings ranging from closed environments such as hospitals, airlines, and casinos to open places such as sports fields and highways. There is little doubt regarding the effectiveness and safety of AEDs to treat people in cardiac arrest. It is intuitive that these devices should be provided in hospitals in areas that are not readily accessible to the traditional responders, the "code blue team." Similarly, it is intuitive to provide AEDs in out-of-hospital settings where the risk of cardiac arrest is high and a response plan involving trained first responders in the use of AEDs is in place. Thus, the Medical Advisory Secretariat reviewed the literature and focused on the components of an AED program in out-of-hospital settings that maximize the effectiveness and cost-effectiveness of the program in the management of cardiac arrest. Search engines included MEDLINE, EMBASE, EconLit and Web sites of other agencies that assess health technologies. Any study that reported results of an AED program in an out-of-hospital setting was included. Studies that did not use AEDs, had a physician-assisted emergency response plan, did not have a program for the use of AEDs, or did not include cardiac arrest as an outcome were excluded.

SUMMARY OF FINDINGS

A total of 133 articles were identified; 62 were excluded after reviewing titles and abstracts. Of the 71 articles reviewed, 8 reported findings of 2 large studies, the Ontario Prehospital Advanced Life Support (OPALS) study and the Public Access Defibrillation (PAD) trial. These studies examined the effect of a community program to respond to cardiac arrest with and without the use of AEDs. Their authors had reported a significant reduction in overall mortality from cardiac arrest with the use of AEDs. Factors That Improve the Effectiveness of an AED Program The PAD trial investigators reported a significant improvement in survival (P = .03) after providing AEDs in public access areas and training volunteers in CPR compared with training volunteers in CPR only. The OPALS study investigators reported odds ratios (ORs) and 95% confidence intervals (CIs) for significant predictors of survival, which were age (OR [age per 10 year], 0.8; CI, 0.8-0.9), arrest witnessed by bystander (OR, 3.9; CI, 2.7-5.5), CPR initiated by bystander (OR, 3.7; CI, 2.6-5.1), CPR initiated by first responder (OR, 1.6; CI, 1.1-2.3), and emergency medical service response within 8 minutes (OR, 3.0; CI, 1.8-5.1). The last 3 variables are modifiable and thus may improve the effectiveness of an AED program. For example, the rate of bystander-initiated CPR was only 14% in the OPALS study, but it was 100% in the PAD trial. This was because PAD trial investigators trained community volunteers whereas the OPALS study investigators did not. Cost-Effectiveness A systematic review of the literature suggests that cost-effectiveness varies from setting to setting. Most of the studies have estimated cost-effectiveness in American settings from a societal perspective; therefore, the results are not applicable to this report. However, results from this review suggest that the incidence of cardiac arrest in out-of-hospital setting in Ontario is 59 per 100,000 people. The mean age of cardiac arrest patients is 69 years. Eighty-five percent of these cardiac arrests occur in homes. Of all the cardiac arrests, 37% have heart rhythm abnormalities (ventricular tachycardia or ventricular fibrillation) that are correctable by delivering shock through an AED. Thus, in an out-of-hospital setting, general use of AEDs by laypersons would not be cost-effective. Special programs are needed in the out-of-hospital setting for cost-effective use of AEDs. One model for the use of AEDs in out-of-hospital settings was examined in the OPALS study. Firefighters and police were trained and provided with AEDs. The total initial cost (in US dollars) of this program was estimated to be $980,000. The survival rate was 3.9% before implementing the AED program and 5.2% after its implementation (OR, 1.33; 95% CI, 1.03-1.7; P = .03). Applying these estimates to cardiac arrest rates in Ontario in 2002, one would expect 54 patients of the total 1,395 cardiac arrests to survive without AEDs compared with 73 patients with AEDs; thus, 19 additional lives might be saved each year with an AED program. It would initially cost $51,579 to save each additional life. In subsequent years, however, total cost would be lower (about $50,000 per year), when it would cost $2,632 to save each additional life per year. One limitation of the OPALS study was that the authors combined emergency medical service response time and application of an AED into a single variable. Thus, it was not possible to tease out the independent effects of reduction in response time and application of an AED on the small improvement in survival. Nevertheless, the PAD study found that when response time was fixed, the application of AED improved survival. There are other delivery models for AEDs in casinos, sports arenas, and airports. The proportion of cardiac arrest at these sites out of the total cardiac arrests in Ontario is between 0.05% and 0.4%. Thus, an AED placed at these sites would likely not be used at all. Of the 85% cardiac arrests that occur in homes, 56% occur in single residential dwellings (houses), 23% occur in multi-residential dwellings (apartments/condominiums), and 6% occur in nursing homes. There is no program in place except the 911 system to reach these patients. Accordingly, the Medical Advisory Secretariat examined the cost-effectiveness of providing AEDs in hospitals, office buildings, apartments/condominiums, and houses. The results suggested that deployment of AEDs in hospitals would be cost-effective in terms of cost per quality adjusted life year gained. Conversely, deployment of AEDs in office buildings, apartments, and houses was not cost-effective. An exception, however, was noted for people at high risk of sudden cardiac arrest; these were patients with a left ventricular ejection fraction less than or equal to 0.35.

CONCLUSIONS

The OPALS study model appears cost-effective, and effectiveness can be further enhanced by training community volunteers to improve the bystander-initiated CPR rates. Deployment of AEDs in all public access areas and in houses and apartments is not cost-effective. Further research is needed to examine the benefit of in-home use of AEDs in patients at high risk of cardiac arrest.

[Automated external defibrillators: perspectives and outlook]

In Germany about 80.000 patients die of sudden cardiac death each year with enormous human, social and economic consequences. Most cases of sudden cardiac death are caused by ischemia-triggered ventricular fibrillation. A precondition for survival of the victims is an optimally and fast reacting "chain of survival". One of the central links of this chain is timely defibrillation, which is the only effective therapy for treatment of ventricular fibrillation. Automated external defibrillators proved to be a major step forward in improvement of resuscitation results. It has been convincingly demonstrated, that these devices not only are safe and efficacious in the hands of rescue personnel of different qualification degrees but also in the hands of minimally trained "first responders" and even in the hands of untrained lay people. This story of success was paralleled by the development of a new generation of biphasic defibrillators, which have a superior efficacy, are lightweight and are even cheaper than conventional devices. It must however kept in mind, that progress offered by these new opportunities will only translate in better resuscitation results, when programmes are thoroughly planned, will stay under continuous quality control with regard to performance of devices and rescuers and if new knowledge in resuscitation is adequately incorporated in action protocols.

Cost-effectiveness of in-home automated external defibrillators for individuals at increased risk of sudden cardiac death

BACKGROUND/OBJECTIVE

In-home automated external defibrillators (AEDs) are increasingly recommended as a means for improving survival of cardiac arrests that occur at home. The current study was conducted to explore the relationship between individuals' risk of cardiac arrest and cost-effectiveness of in-home AED deployment.

DESIGN

Markov decision model employing a societal perspective.

PATIENTS

Four hypothetical cohorts of American adults 60 years of age at progressively greater risk for sudden cardiac death (SCD): 1) all adults (annual probability of SCD 0.4%); 2) adults with multiple SCD risk factors (probability 2%); 3) adults with previous myocardial infarction (probability 4%); and 4) adults with ischemic cardiomyopathy unable to receive an implantable defibrillator (probability 6%).

INTERVENTION

Strategy 1: individuals suffering an in-home cardiac arrest were treated with emergency medical services equipped with AEDs (EMS-D). Strategy 2: individuals suffering an in-home cardiac arrest received initial treatment with an in-home AED, followed by EMS.

RESULTS

Assuming cardiac arrest survival rates of 15% with EMS-D and 30% with AEDs, the cost per quality-adjusted life-year gained (QALY) of providing in-home AEDs to all adults 60 years of age is 216,000 dollars. Costs of providing in-home AEDs to adults with multiple risk factors (2% probability of SCD), previous myocardial infarction (4% probability), and ischemic cardiomyopathy (6% probability) are 132,000 dollars, 104,000 dollars, and 88,000 dollars, respectively.

CONCLUSIONS

The cost-effectiveness of in-home AEDs is intimately linked to individuals' risk of SCD. However, providing in-home AEDs to all adults over age 60 appears relatively expensive.