OHCA-Bundle-Resuscitation.Pdf

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Resuscitation

jo urnal homepage: www.elsevier.com/locate/resuscitation

Clinical paper

Effectiveness of a community based out-of-hospital

cardiac arrest (OHCA) interventional bundle:

Results of a pilot study

a, b a c

Pamela Jia Min Tay *, Pin Pin Pek , Qiao Fan , Yih Yng Ng ,

d e f

Benjamin Sieu-Hon Leong , Han Nee Gan , Desmond Renhao Mao ,

c g h i

Michael Yih Chong Chia , Si Oon Cheah , Nausheen Doctor , Lai Peng Tham ,

b,j

Marcus Eng Hock Ong

Duke-NUS Medical School, Singapore

Department of Emergency Medicine, Singapore General Hospital, Singapore

Emergency Department, Tan Tock Seng Hospital, Singapore

Emergency Medicine Department, National University Hospital, Singapore

Accident & Emergency, Changi General Hospital, Singapore

Acute and Emergency Care Centre, Khoo Teck Puat Hospital, Singapore

Emergency Medicine Department, Ng Teng Fong General Hospital, Singapore

Emergency Department, Sengkang General Hospital, Singapore

Children’s Emergency, KK Women’s and Children’s Hospital, Singapore

Health Services and Systems Research, Duke-NUS Medical School, Singapore

Abstract

Background: 70% of Out-of-hospital cardiac arrests (OHCA) in Singapore occur in residential areas, and are associated with poorer outcomes. We

hypothesized that an interventional bundle consisting of Save-A-life (SAL) initiative (cardiopulmonary resuscitation (CPR)/automated external

defibrillator (AED) training and public-housing AED installation), dispatcher-assisted CPR (DA-CPR) program and myResponder (mobile application)

will improve OHCA survival.

Methods: This is pilot data from initial implementation of a stepped-wedge, before-after, real-world interventional bundle in six selected regions. Under

the SAL initiative, 30,000 individuals were CPR/AED trained, with 360 AEDs installed. Data was obtained from Singapore’s national OHCA Registry. We

included all adult patients who experienced OHCA in Singapore from 2011 to 2016 within study regions, excluding EMS-witnessed cases and cases due

to trauma/drowning/ electrocution. Cases occurring before and after intervention were allocated as control and intervention groups respectively.

Survival was assessed via multivariable logistic regression.

Results: 1241 patients were included for analysis (Intervention: 361; Control: 880). The intervention group had higher mean age (70 vs 67 years),

survival (3.3% [12/361] vs. 2.2% [19/880]), pre-hospital return of spontaneous circulation (ROSC) (9.1% [33/361] vs 5.1% [45/880]), bystander CPR

(63.7% [230/361] vs 44.8% [394/880]) and bystander AED application (2.8% [10/361] vs 1.1% [10/880]). After adjusting for age, gender, race and

significant covariates, the intervention was associated with increased odds ratio (OR) for survival (OR 2.39 [1.02 5.62]), pre-hospital ROSC (OR 1.94

[1.15 3.25]) and bystander CPR (OR 2.29 [1.77 2.96]).

À À

Conclusion: The OHCA interventional bundle (SAL initiative, DA-CPR, myResponder) significantly improved survival and is being scaled up as a

national program.

Keywords: Cardiac arrest, Bystander CPR, AED, Cardiac outcomes

* Corresponding author.

E-mail address: [email protected] (P.J.M. Tay).

https://doi.org/10.1016/j.resuscitation.2019.10.015

Received 21 May 2019; Received in revised form 7 September 2019; Accepted 6 October 2019

Available online xxx

Please cite this article in press as: P.J.M. Tay, et al., Effectiveness of a community based out-of-hospital cardiac arrest (OHCA)

interventional bundle:DownloadedResults of fora Anonymouspilot study, UserResuscitation (n/a) at Singhealth(2019), from ClinicalKey.comhttps://doi.org/10.1016/j.resuscitation.2019.10.015 by Elsevier on November 15, 2019. For personal use only. No other uses without permission. Copyright ©2019. Elsevier Inc. All rights reserved.

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From 2016 onwards, the interventional bundle will be further scaled up

Introduction

in phases across all regions of Singapore. This was a pre-planned

interim analysis of the interventional bundle to allow for a midpoint

Out-of-hospital cardiac arrests (OHCA) are a leading cause of death analysis of its effectiveness. We intend to conduct a further analysis

globally, and a major public health issue. Yearly, an estimated with full implementation of the intervention across all regions of

700,000 people across Europe and North America suffer from OHCA, Singapore. The study was approved by the local Institutional Review

of whom only approximately 10% survive. Across Asia-Pacific and Boards and was classified as minimal risk research with waiver of

Singapore, there has been a higher incidence of OHCA, likely informed consent.

contributed by lifestyle diseases and an ageing population. Each

minute of delay in initiating resuscitation contributes to a 7 10% Study area, EMS system and dispatch of first responders

decreased probability of survival, highlighting the time-sensitive

2 2

nature of OHCA and the importance of early defibrillation and early Singapore is a city-state, with a land area of 710 km and a population

3 8

resuscitation among others in the chain of survival. of 5.1 million in 2011. Singapore has a comprehensive, single

Singapore has shown good progress in strengthening the chain of provider, fire-based emergency medical services (EMS) system run

survival over the last fifteen years with a number of key interventions. by the Singapore Civil Defence Force (SCDF). EMS is activated via a

This includes expansion of Singapore’s pre-hospital emergency centralized ‘995’ dispatch system, and only sends cases to public

medical services (EMS) ambulance fleet from 32 (2001) to 46 (2010), hospitals.

use of intravenous epinephrine and laryngeal mask airways (2004)

and mechanical CPR in ambulances (2011). We have since seen a Save-A-life initiative

significant improvement in Utstein (witnessed, shockable, cardiac

aetiology) survival to discharge from 2.5% (2001 2004) to 11.0% The Save-A-life (SAL) initiative was developed out of a need to

4 À

(2010 2012). More recent interventions include the introduction of improve community first response to residential cardiac arrest cases,

fire bikers (2012) and scaling up dispatcher-assisted CPR (DA-CPR) as a collaboration between SCDF, Ministry of Health, Singapore Heart

in 2012. DA-CPR involves rapid over-the-phone assessment by EMS Foundation and the People’s Association. First launched in July 2015

dispatchers, followed by providing concise CPR instructions to the in residential estates of six selected regions (Tampines, Pasir Ris,

caller as required. Radin Mas, Choa Chu Kang, Bukit Panjang and Bedok), the program

In Singapore, OHCA occurring within residential areas (residential was subsequently expanded to residential estates across Singapore.

OHCA) account for 70% of cardiac arrest cases and are associated Boundaries for these regions were based on political boundaries to

with poorer survival outcomes as compared to OHCA occurring in facilitate implementation of the intervention. Pilot regions were

public areas (non-residential OHCA). To further develop our selected on the basis of having a high proportion of elderly or high

community response to cardiac arrests and address this gap, OHCA incidence (Fig. 2) .

Singapore recently launched an interventional bundle consisting of This program offered free training in chest-compression only

various community based programs. A key component is the Save-A- cardiopulmonary resuscitation (CPR) and automated external

life (SAL) initiative which consists of free CPR/AED training sessions defibrillator (AED) use, with signups conducted through the local

for residents coupled with AED installation at public housing blocks. community centres and schools. Close to 30,000 individuals

This is supplemented by dispatcher-assisted CPR (DA-CPR), and a were trained by 31st December 2016. CPR/AED training

first responder mobile application ‘myResponder’. This study shows sessions were conducted by a number of different agencies,

pilot data from initial implementation of the interventional bundle in six with standardized teaching material covering recognition of

selected geographical regions. cardiac arrest, chest-compression CPR, AED application.

We hypothesized that the interventional bundle would improve Public-access defibrillators were also installed at the void decks

bystander CPR rates, thereby contributing toward a significant of public housing developments in these selected regions, with a

increase in OHCA survival. We aimed to assess the effectiveness total of 360 AEDs installed under this initiative. A void deck is a

of the community interventional bundle on OHCA survival rates public-access open area on the ground floor of public housing

(survival to discharge or survival to 30-days post cardiac arrest). developments in Singapore.

Secondary outcomes such as pre-hospital return of spontaneous

circulation (ROSC), bystander CPR rates, AED administration rates, Data collection and definitions

and neurological outcome were also assessed.

PAROS and medical records

Data were collected prospectively under the Pan-Asian Resuscitation

Methods Outcomes Study (PAROS), using a standardized Utstein-style data

form comprising 48 parameters documenting the pre-hospital and

Overview of study design emergency department (ED) notes and hospital discharge records.

Data collection for PAROS was standardized based on an expanded

This was a planned stepped-wedge, before-after, real-world interven- template of the Utstein variables. EMS providers on scene determined

tional study. The interventional bundle was piloted in six selected if these were cardiac arrests, and documented them accordingly. All

regions from July 2015 (Fig. 2). Study period was from 1st January OHCA cases undergo 100% Quality Improvement review, including

2011 to 31st December 2016. This was a stepped-wedge design confirming that they were actually cardiac arrest cases. For each

where different clusters implement the intervention over different time patient, EMS data was obtained from both dispatch records and

points until all regions have undergone the intervention. This allows ambulance patient case notes. Hospital records were obtained from

for a robust research study design even with logistical constraints. the respective ED, intensive care units and wards.

Please cite this article in press as: P.J.M. Tay, et al., Effectiveness of a community based out-of-hospital cardiac arrest (OHCA)

interventional bundle:DownloadedResults of fora pilotAnonymousstudy, UserResuscitation (n/a) at Singhealth(2019), from ClinicalKey.comhttps://doi.org/10.1016/j.resuscitation.2019.10.015 by Elsevier on November 15, 2019. For personal use only. No other uses without permission. Copyright ©2019. Elsevier Inc. All rights reserved.

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Time intervals 2.18.24, an open source mapping software. First arrest rhythm was

All digital time stamps were automatically logged into the computer- defined as the first cardiac rhythm captured by any applied AED.

ized central dispatch system. EMS response time was taken as time ROSC refers to restoration of a palpable pulse, regardless of how

from receiving dispatch call to time of ambulance arrival at scene. transient. Pre-hospital ROSC refers to any ROSC prior to arrival at the

emergency department, while ED ROSC refers to any ROSC that

Definitions occurs in the ED. Any ROSC refers to at least one ROSC either in the

field or in the ED.

All patients with OHCA were confirmed by the absence of a pulse,

unresponsiveness and apnea. Study population includes all persons Main outcome measures

16 years of age or older who had OHCA in Singapore, as confirmed by

absence of pulse, unresponsiveness and apnea. Inclusion criteria The primary outcome measure of this analysis was survival to

include those for whom resuscitation was attempted and who were discharge or survival to 30-days post cardiac arrest, and is referred to

attended to by EMS, over the study period from January 2011 to as survival. Secondary outcome measures include bystander CPR

December 2016. Exclusion criteria includes cases where resuscita- rates, bystander AED rates, pre-hospital ROSC and neurological

tion was not attempted or persons who were pronounced dead at outcome at discharge. Cerebral performance category (CPC) scores

scene, OHCA cases due to trauma, drowning and electrocution, or ranging from 1 to 4 were assigned, with scores of 1 and 2 defined as a

cases where the OHCA collapse was witnessed by EMS. Patients with favourable neurological outcome.

obvious evidence of death or those with do-not-resuscitate orders

were also excluded. Statistical analysis

Bystanders are anyone who were present at the time of collapse,

but were not part of the organized, formal emergency response Data analysis was performed using SPSS Version 24. Chi-square

system; while EMS includes fire-bikers and EMS personnel arriving by test was carried out for binary covariates while two sample t-test was

ambulance that were dispatched by SCDF’s Control room. Bystander done for continuous variables, for factors known to be associated

AED use was defined as the application of AED pads on the cardiac with the various outcomes (cardiac arrest survival, pre-hospital

12,13

arrest victim by laypersons. Location of collapse was defined as where ROSC and bystander CPR). Multivariable logistic regression

the patient was at the time of incident and recorded as a six digit postal was performed, adjusting for age, gender, race and included only

code which was converted to longitude and latitude readings and variables significant at p-value <0.2. Statistical significance was set

mapped on Quantum Geographic Information Systems (QGIS) at p-value<0.05.

Fig. 1 – Selection criteria for out-of-hospital cardiac arrest cases.

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Fig. 2 – Roadmap for implementation of intervention.

Results intervention led to significant improvements in OHCA survival in

the regions where it was implemented. This demonstrates the

importance of employing a systems-level approach in targeting

Fig. 1 shows the flow diagram of OHCA cases included in the analysis. public health issues such as this.

1406 OHCA cases occurred in the six selected regions in Singapore Previous public CPR education interventions showed varying

from 2011 to 2016, with 1241 cases eventually analyzed after results. A statewide multifaceted campaign launched by Arizona in

excluding OHCA cases where victims were younger than 16 years old, 2005 with 30,000 people directly trained in CPR found an increase in

cases pronounced dead on scene, EMS-witnessed cases, or cases overall survival from 3.7% to 9.8%. This involved multiple

secondary to trauma, electrocution and drowning. Fig. 2 shows the modalities including an online website, video training, in-person

roadmap for implementation of the SAL initiative in the six selected training, school training kits and newspaper articles. Another

regions. These regions serve as the basis for selection of control and community-based program involving peer-to-peer CPR training in

intervention groups (based on date cut-offs), with 880 control cases areas with high cardiac arrest incidences demonstrated increased

and 361 intervention cases. bystander CPR rates. Conversely, a once-off non-targeted

Table 1 shows baseline characteristics of included OHCA cases by community CPR training for 2000 passers-by at seven different

intervention and control groups. Mean age of OHCA cases was 67 public locations found no impact on bystander CPR frequency or

years (SD 16.1) for control and 70 years (SD 15.3) for intervention survival outcomes.

Æ Æ

group. OHCA cases in the intervention group were significantly more We also found significant improvements in pre-hospital ROSC and

likely to receive bystander CPR (63.7% vs 44.8%, p-value <0.001), bystander CPR rates. Pre-hospital ROSC in the field is the strongest

receive pre-hospital epinephrine (64.5% vs 55.3%, p-value = 0.003) predictor of survival to hospital discharge, and is consistent with our

and to have a pre-hospital ROSC (9.1% vs 5.1%, p-value = 0.01). The findings of both increased pre-hospital ROSC and survival rates.

intervention group also had significantly higher rates of bystander AED While we showed an increased percentage of patients with favourable

application (2.8% vs 1.1%, p-value = 0.047) and bystander defibrillation neurological outcome (CPC 1 or 2) (Table 1), this was not statistically

(0.6% vs 1.7%, p-value = 0.09). OHCA in the intervention group were significant and its association with the intervention could not be

more likely to survive to discharge or to 30-days post cardiac arrest accurately assessed due to the small number of cases (n = 31).

(2.2% vs 3.3%, p-value = 0.23). There was also an increased Likelihood of OHCA survival in Singapore is five times lower in

18 20

percentage of OHCA cases with favorable neurological outcome at residential than non-residential OHCA. À Poor outcomes are

66.7% (n = 8) compared to 47.4% (n = 9) in control group (Table 1), but attributed to differing characteristics: residential OHCA individuals

this was not statistically significant (p-value = 0.461). This is likely due to were often older, had lower rates of bystander CPR, were more often

insufficient power because of the small sample size. unwitnessed, less often found in ventricular fibrillation, and had longer

5,19,21,22

Table 2 is a summary table showing adjusted odds ratios from EMS response times. The SAL initiative specifically targets

multivariable logistic regression for ourvarious outcomes (survival, pre- residents of the selected regions by recruiting participants through the

hospital ROSC and bystander CPR). The intervention was associated local community centres and schools. We posit that with 70% of OHCA

with an increase in survival rate with adjusted OR of 2.39 (95% CI 1.02 occurring in residential areas, such a targeted intervention would lead

5.62). Adjusted OR for pre-hospital ROSC was 1.94 (95% CI 1.15 to greater downstream improvements on survival.

3.25), with OR 2.29 (95% CI 1.77 2.96) for overall bystander CPR. In contrast to a recent Danish study which found that public

À À

Table 3 shows the unadjusted and adjusted odds ratios for bystander education programs tend to have a greater impact on OHCA occurring

CPR and the subgroups of residential vs non-residential OHCA. in public areas, rather than residential OHCA, we found that our

Intervention was significant for increased bystander CPR for residential interventional bundle significantly increased rates of bystander CPR in

OHCA, with OR of 2.40 (95% CI 1.83 3.14), but not for non-residential the six selected regions, particularly for residential OHCA (Table 3).

OHCA with OR at 1.46 (95% CI 0.62 3.43) (Table 3). We wish to highlight that the interventions implemented in the Danish

study were not targeted at residential areas; whereas in our study,

AED installation and community CPR/AED trainings were specific to

Discussion residential areas only. The difference in results may also be due to the

relatively small number of non-residential OHCA cases (n = 143) such

This study aimed to improve OHCA survival through a community that we are unable to accurately assess the impact of the

based OHCA interventional bundle. We showed that the interventional bundle in this subgroup.

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Table 1 – Baseline characteristics of study population.

Variable Control (N = 880) Intervention (N = 361) p-value

Age

Mean (SD) 67.20 ( 16.1) 70.20 ( 15.3) 0.002*

Æ Æ

Less than 65 years old 372 (42.3) 124 (34.3) 0.011*

Gender, male (n, %) 557 (63.3) 206 (57.1) 0.046*

Ethnicity (n, %) 0.646

Chinese 579 (65.8) 232 (64.3)

Malay 203 (23.1) 77 (21.3)

Indian 72 (8.2) 41 (11.4)

Others 26 (3.0) 11 (3.0)

Medical history (n, %)

Heart disease 337 (39.3) 163 (46.0) 0.034*

Diabetes 325 (37.9) 155 (43.8) 0.061*

Hypertension 527 (61.5) 248 (70.1) 0.005*

Location (n, %) 0.205

Home residence 772 (87.7) 326 (90.3)

Non-residential 108 (12.3) 35 (9.7)

Witnessed arrest 521 (59.2) 215 (59.6) 0.949

Bystander CPR 394 (44.8) 230 (63.7) <0.001*

Bystander AED applied 10 (1.1) 10 (2.8) 0.047*

Bystander defibrillation 5 (0.6) 6 (1.7) 0.09

Initial shockable rhythm 154 (17.5) 51 (14.1) 0.153

Mechanical CPR 527 (59.9) 283 (78.4) <0.001*

Pre-hospital advanced airway 784 (89.1) 329 (91.1) 0.305

Pre-hospital epinephrine 487 (55.3) 233 (64.5) 0.003*

Pre-hospital defibrillation 231 (26.3) 79 (21.9) 0.113

ED defibrillation 179 (20.3) 55 (15.2) 0.038*

Response time <8 minutes 334 (38.0) 165 (45.7) 0.013*

PCI 23 (2.6) 12 (3.3) 0.571

CABG 0 (0.0) 0 (0.0)

Therapeutic hypothermia 36 (4.1) 20 (5.5) 0.292

ECMO 0 (0.0) 0 (0.0) À

Outcomes

Pre-hospital ROSC 45 (5.1) 33 (9.1) 0.010*

ED ROSC 262 (29.8) 95 (26.3) 0.241

Any ROSC 287 (32.6) 115 (31.9) 0.841

Survival to admission (n, %) 147 (16.7) 48 (13.3) 0.145

Survival rate 19 (2.2) 12 (3.3) 0.234

Post-arrest CPC(1/2) 9/31 (47.4) 8/31 (66.7) 0.461

CPR: Cardiopulmonary resuscitation; AED: Automated external defibrillator; ED: Emergency department; Response time: Time from dispatch call received to time

emergency medical services arrives at scene; PCI: Percutaneous coronary intervention; CABG: Coronary artery bypass grafting; ECMO: Extracorporeal membrane

oxygenation; ROSC: Return of spontaneous circulation; Survival rate: Survival to discharge/survival to 30-day post cardiac arrest; CPC: Cerebral performance category. * p-value<0.05.

Post-arrest Cerebral performance category was computed only for survivors.

Bystander defibrillation has been shown to effectively improve from 1.1% to 2.8% (Total cases: n = 20) and bystander defibrillation

24 27

survival rates À and double neurologically intact survival rates for from 0.6% to 1.7% (Total cases: n = 11) with the intervention (Table 1),

28,29

OHCA. While Singapore already has AEDs installed in locations but the small number of cases in which this occurred precludes reliable

with a high likelihood of cardiac arrest (such as ports, airports and analysis of the intervention effect. The effect of intervention on

immigration checkpoints), residential areas remain poorly bystander AED use should be assessed again in future studies.

30,31

equipped. Fig. 3 shows the AEDs newly installed under the Launched in April 2015, myResponder is a mobile phone

SAL initiative. The location of these AEDs can be seen to closely geolocation application that provides real-time alerts about OHCA

correlate with the previous occurrence of OHCA. Singapore has cases. The application alerts users if a potential cardiac arrest occurs

historically struggled with low bystander AED rates at about 1%, with within 400 m of their location, and also provides information on the

only 57.2% of survey respondents believing that adults should be AED nearest available public access AED. This allows for immediate

trained. Besides the unavailability of AEDs, other contributory mobilization of CPR-trained bystanders to an OHCA case, thereby

factors includes fear of causing harm, or misconception of the difficulty facilitating early CPR and early defibrillation. ‘Pulsepoint’ is a similar

of AED application. By increasing the visibility and availability of phone application utilized across 600 United States communities,

public-access AEDs, we aim to encourage and promote public which demonstrated an 80% bystander CPR rate when Pulsepoint

awareness of bystander AED use. Comparison of intervention and users arrived on scene prior to EMS. Unpublished data from 2016

control groups showed an improvement in bystander AED application showed that 35% of myResponders who were activated and

Please cite this article in press as: P.J.M. Tay, et al., Effectiveness of a community based out-of-hospital cardiac arrest (OHCA)

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Table 2 – Multivariable logistic regression analysis of survival, pre-hospital return of spontaneous circulation and

bystander CPR.

Variable Survival Pre-hospital ROSC Bystander CPR

Adjusted OR (95% CI) p-value Adjusted OR (95% CI) p-value Adjusted OR (95% CI) p-value

Intervention 2.39 (1.02 5.62) 0.045* 1.94 (1.15 3.25) 0.012* 2.29 (1.77 2.96) <0.001***

À À À

Age 0.98 (0.95 1.00) 0.074 0.99 (0.97 1.01) 0.240 1.00 (0.99 1.00) 0.156*

À À À

Gender, male 0.78 (0.31 1.98) 0.606 1.24 (0.71 2.18) 0.449 0.99 (0.78 1.26) 0.939 À À À

Ethnicity

Chinese 1.00 0.224 1.00 0.013* 1.00 0.466

Malay 0.29 (0.09 0.04) 0.038* 0.42 (0.21 0 0.84) 0.013* 0.92 (0.70 1.23) 0.589

À À

Indian 0.83 (0.21 3.35) 0.793 0.18 (0.04 0.79) 0.022* 0.72 (0.48 1.09) 0.122

À À À

Others 0.63 (0.09 4.34) 0.640 0.45 (0.09 2.20) 0.320 0.85 (0.43 1.67) 0.632

À À À

Location, home 0.71 (0.37 1.35) 0.296 0.48 (0.33 0.70) <0.001***

À À À À

Bystander-witnessed arrest 1.28 (0.47 3.49) 0.628 1.15 (0.91 1.45) 0.247

À À À À

Initial shockable rhythm 6.70 (1.52 29.47) 0.012* 1.66 (0.72 3.85) 0.238

À À À À

Pre-hospital defibrillation 5.87 (1.07 32.33) 0.042* 2.31 (1.02 5.20) 0.044*

À À À À

Pre-hospital advanced airway 0.21 (0.07 0.66) 0.008** 0.45 (0.22 0.93) 0.031*

À À À À

Pre-hospital epinephrine 1.29 (0.76 2.18) 0.348

À À À À À

Bystander CPR 1.37 (0.56 3.37) 0.498 1.79 (1.04 3.08) 0.035*

À À À À

Bystander AED 1.21 (0.26 5.57) 0.807 4.31 (1.47 12.64) 0.008**

À À À À

Response time <8 min. 1.52 (0.69 3.37) 0.304 1.57 (0.96 2.57) 0.072 À À À À * p-value<0.05.

** p-value<0.01.

*** p-value<0.001.

Table 3 – Multivariable logistic regression for bystander cardiopulmonary resuscitation.

Variable Overall (n = 1241) Residential OHCA (n = 1098) Non-residential OHCA (n = 143)

Unadjusted OR Adjusted OR Unadjusted OR Adjusted OR Unadjusted OR Adjusted OR

(95% CI) (95% CI) (95% CI) (95% CI) (95% CI) (95% CI)

Intervention 2.17 (1.68 2.79) 2.29 (1.77 2.96)** 2.33 (1.79 3.04)** 2.40 (1.83 3.14)** 1.41 (0.62 3.25) 1.46 (0.62 3.43)

À À À À À À

Age 1.00 (0.99 1.00) 1.00 (0.99 1.00)* 1.00 (0.99 1.01) 0.99 (0.99 1.00) 0.99 (0.97 1.01) 1.00 (0.97 1.02)

À À À À À À

Gender, male 1.03 (0.82 1.30) 0.99 (0.78 1.26) 0.93 (0.73 1.18) 0.93 (0.72 1.20) 1.91 (0.88 4.18) 1.86 (0.82 4.21) À À À À À À

Ethnicity

Chinese 1.00 1.00 1.00 1.00 1.00 1.00

Malay 0.98 (0.75 1.28) 0.92 (0.70 1.23) 0.91 (0.68 1.22) 0.88 (0.65 1.19) 1.58 (0.68 3.67) 1.47 (0.61 3.55)

À À À À À À

Indian 0.82 (0.55 1.22) 0.72 (0.48 1.09) 0.77 (0.50 1.17) 0.67 (0.44 1.04) 1.37 (0.39 4.78) 1.14 (0.31 4.14)

À À À À À À

Others 0.91 (0.47 1.77) 0.85 (0.43 1.67) 0.85 (0.42 1.71) 0.76 (0.37 1.56) 1.82 (0.18 18.22) 1.99 (0.20 20.39)

À À À À À À

Location, home 0.49 (0.34 0.70) 0.48 (0.33 0.70)**

À À À À À À

Bystander-witnessed 1.22 (0.97 1.53) 1.15 (0.91 1.45) 1.13 (0.89 1.44) 1.14 (0.89 1.46) 1.31 (0.56 3.07) 1.24 (0.51 2.99) À À À À À À arrest

* p-value<0.05.

responded arrived before EMS, and further studies would enhance OHCA survival rate cannot be proven. Changes to Singapore’s EMS

our understanding of the impact of this intervention. system such as introduction of the fire biker’s scheme were not

DA-CPR is the final component to this interventional bundle. accounted for. While the myResponder application was a part of the

Implemented in 2012, DA-CPR involves directed over-the-phone intervention bundle, it was not adjusted for in the analysis as this data

CPR instructions provided by an EMS dispatcher. DA-CPR has been was not available at the time this study was conducted. Implementa-

associated with a significant increase in bystander CPR, with tion of an interventional bundle also means we are unable to determine

improved survival and neurological outcomes post cardiac arrest. the specific effectiveness of each component of the intervention.

Even in cases with barriers to CPR (such as inability to move patient, However we hypothesize that the interventional bundle targets

refusal by caller), DA-CPR rates of 67.9% was achieved. Both the different components of the ‘chain of survival’ and would therefore

SAL initiative and DA-CPR aim to reduce barriers to bystander CPR, better fulfil our aim of improving OHCA survival. We were unable to

thereby complementing each other. account for the effect of the SAL trained individuals who live or work

This study has several limitations. As a stepped-wedge interven- outside of our intervention regions. Class size for CPR/AED trainings

tional study, a causative relationship between the intervention and also varied from 14 people up to 700 people. While standardizing the

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Fig. 3 – Maps showing regions of intervention (A) Before implementation of SAL initiative (B) After implementation of

SAL initiative.

trainings provided would ensure quality assurance, the scale of this process. Finally, this analysis is only on pilot data. We intend to

initiative poses huge logistical constraints. Future studies assessing conduct further analysis in a stepped wedge manner when the full

the quality of training provided and quality of CPR administered by study is completed using a mixed-effects analysis, which involves a

these trained individuals would help to better optimize this training time effect in addition to the cluster and intervention effects.

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8 À

9. Resident Population by Planning Area/Subzone, Age Group and Sex,

Conclusion 2015-Data.gov.sg n.d. https://data.gov.sg/dataset/resident-

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Implementation of the interventional bundle consisting of resident-

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targeted community CPR training and public-access AED installation

cardiac arrests across 7 countries in Asia: The Pan Asian

supplemented by DA-CPR and myResponder, was associated with Resuscitation Outcomes Study (PAROS). Resuscitation 2015;96:100

increased OHCA survival, pre-hospital ROSC and bystander CPR. 8, doi:http://dx.doi.org/10.1016/j.resuscitation.2015.07.026.

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These findings support the feasibility and effectiveness of the SAL

cardiopulmonary resuscitation and survival according to ambulance

initiative as a community based intervention. Further evaluation is

response times after out-of-hospital cardiac arrest. Circulation planned.

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Conflict of interest statement cardiopulmonary resuscitation in emergency department. World J

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j.1920-8642.2013.03.005.

All the authors have neither commercial nor personal associations or

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any sources of support that might pose a conflict of interest in the

with improved cardiac arrest survival in a multicenter basic life support/

subjects discussed in this manuscript.

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Shahidah and Mr Sherman Lian from Department of Emergency

TAKE10: a community approach to teaching compression-only CPR to

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10903127.2018.1459978.

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