This cohort study estimates the rate of automated external defibrillator (AED) use prior to emergency medical service (EMS) arrival in pediatric out-of-hospital cardiac arrest (OHCA) and assesses whether AED use is associated with neurological outcomes in this population.
Key Points
Question
What is the current rate of automated external defibrillator (AED) pad application before emergency medical service (EMS) arrival in pediatric out-of-hospital cardiac arrest (OHCA), and is AED pad application associated with neurological outcomes?
Findings
In this cohort study of 3352 pediatric patients with OHCA in Japan, AED pads were applied before EMS arrival in 5.5% of pediatric OHCAs, and AED pad application was provided more often at school and when bystander CPR was provided, but less often at home, at night, and among infants. AED pad application was associated with higher 1-month survival with a favorable neurological outcome after OHCA.
Meaning
These findings could serve as foundational data for formulating strategies to further increase AED pad application for pediatric patients with OHCA.
Abstract
Importance
The current rate of automated external defibrillator (AED) pad application before emergency medical service (EMS) arrival in pediatric out-of-hospital cardiac arrest (OHCA) in Japan has not been sufficiently investigated.
Objective
To describe the current rate of AED pad application and evaluate factors associated with AED pad application as well as factors associated with survival in pediatric patients with OHCA.
Design, Setting, and Participants
This was a nationwide, prospective, population-based cohort study using data from the All-Japan Utstein Registry between 2021 and 2023. Pediatric patients with OHCA aged 0 to 17 years in whom resuscitation was attempted before EMS arrival were included. Data analyses were conducted from January to May 2026.
Exposure
OHCA stratified by age (infants [<1 year], younger children [1-4 years], older children [5-12 years], and adolescents [13-17 years]).
Main Outcomes and Measures
The outcome measures were the application of AED pads before EMS arrival as well as 1-month survival with a favorable neurological outcome, defined as a cerebral performance category scale of 1 or 2. Multivariable logistic regression analyses were performed to estimate adjusted odds ratios (aORs) and 95% CIs for factors associated with each outcome.
Results
A total of 3352 pediatric patients with OHCA were analyzed. The median (IQR) age was 3 (1-4) years, 1983 patients (59.2%) were male, and 185 patients (5.5%) received AED pad application before EMS arrival. Arrests among infants (aOR, 0.28; 95% CI, 0.13-0.47) and younger children (aOR, 0.22; 95% CI, 0.10-0.49) vs adolescents, arrests occurring at home vs another public area (aOR, 0.06; 95% CI, 0.03-0.11), and arrests occurring at nighttime vs daytime (aOR, 0.52; 95% CI, 0.33-0.82) were significantly associated with a reduced probability of AED pad application before EMS arrival. In contrast, arrests occurring at school vs another public area (aOR, 6.74; 95% CI, 3.73-12.21) and receipt of bystander CPR (aOR, 28.69; 95% CI, 12.91-63.75) were associated with an increased probability of AED pad application before EMS arrival. Favorable neurological outcome was significantly higher in the AED pad application group than in the non–AED pad application group (aOR, 3.11; 95% CI, 1.30-7.44). Ventricular fibrillation as first documented rhythm had a large magnitude of association with increased favorable neurological outcome (aOR, 27.49; 95% CI, 13.95-54.19).
Conclusions and Relevance
In this cohort study from Japan, approximately 5% of pediatric patients with OHCA received AED pad application before EMS arrival, and AED pad application was associated with higher odds of 1-month survival with a favorable neurological outcome. Further efforts are needed to increase AED access and use in public places where children gather, including schools.
Introduction
The incidence of pediatric out-of-hospital cardiac arrest (OHCA) is lower than that of adults.1,2 However, its impact is profound, with devastating consequences for children, families, and society. Importantly, despite advances in resuscitation science, health outcomes after pediatric OHCA remain poor.2,3 Several studies reported that the use of automated external defibrillators (AEDs) by bystanders was associated with better outcomes among pediatric patients with OHCA,4,5 but AED use before emergency medical service (EMS) arrival remains uncommon in pediatric OHCA. However, characteristics associated with AED pad application before EMS arrival, as well as the association of AED pad application with survival outcomes, have not been sufficiently investigated. Therefore, evaluating the characteristics and outcomes of pediatric patients with AED pad application before EMS arrival is needed to further increase them receiving bystander defibrillation. Using a national database, this study aimed to evaluate the factors associated with the application of AED pad application before EMS arrival for pediatric patients with OHCA in Japan. The study also evaluated factors associated with OHCA outcomes.
Methods
Study Design, Population, and Setting
This cohort study was approved by the ethics committees of The University of Osaka (approval number 24268). The requirement of written informed consent was waived, and the researchers analyzed only deidentified (anonymized) data. Reporting follows the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.6 We conducted an analysis of data from the All-Japan Utstein Registry collected between 2021 and 2023 by the Fire and Disaster Management Agency. The registry is a nationwide, prospective, population-based database of OHCA based on the international Utstein Style.7 Details of the registry have been previously described.8 In addition, to obtain information on location of arrest and AED pad application before EMS arrival, which were not included in the All-Japan Utstein Registry, we used data linked to the All-Japan emergency transport records.9,10,11 Details of EMS systems in Japan, data collection, and quality control are described in the eMethods in Supplement 1.
We focused on pediatric patients with OHCA aged 0 to 17 years who were resuscitated (chest compressions and/or shock delivery) by bystanders or EMS personnel and then transported to medical institutions between January 1, 2021, and December 31, 2023. In this study, we excluded patients with no resuscitation attempts, those with EMS-witnessed arrests, and those lacking data on witness status, first documented rhythm, or bystander cardiopulmonary resuscitation (CPR). Cohort launching, data collection, and their assurance were performed by the Fire and Disaster Management Agency, while data analyses, manuscript writing, and publication were performed by the authors.
Dissemination of Public-Access AEDs and CPR
In Japan, public-access AEDs by citizens have been available since July 2004. Public-access AED deployment at public spaces such as schools, sports and cultural facilities, workplaces, and transportation facilities depends on both private and public initiatives.12 The available number of AEDs deployed in public spaces was approximately 690 000 in 2023, estimated based on data from AED sales.12 CPR training programs have been conducted mainly by local fire departments, based on the Japanese CPR guidelines.7,13
Outcome Measures
The outcome measures were the application of AED pads before EMS arrival as well as 1-month survival with a favorable neurological outcome. Favorable neurological outcome was defined as a cerebral performance category scale of 1 or 2.8
Statistical Analysis
Patient characteristics and outcomes with or without AED pad application were assessed using Wilcoxon rank-sum tests for continuous variables with skewed distributions and Pearson χ2 tests for categorical variables. Exploratory analyses were conducted to investigate the factors associated with (1) AED pad application and (2) 1-month survival with a favorable neurological outcome among pediatric patients with OHCA. For each outcome, both univariable and multivariable logistic regression analyses were performed to estimate adjusted odds ratios (aORs) and 95% CIs for factors prior to EMS arrival. The following variables were adjusted for in both analyses: year (2021, 2022, or 2023), sex (male or female), age group (infants [<1 year], younger children [1-4 years], older children [5-12 years], and adolescents [13-17 years]),14 week time (weekday vs weekend), time (daytime [9:00 AM to 4:59 PM] or nighttime [5:00 PM to 8:59 AM]), location (home, school, other public area, or other location), type of witness status (none, family, friends, passerby, or other witness), bystander CPR (no or yes), and dispatcher CPR instruction (no or yes). In a sensitivity analysis, we built the multivariable model excluding bystander CPR for factors associated with AED pad application because bystander CPR would be associated with AED pad application and could affect the estimated associations of other factors.
Further adjustment for 1-month survival with a favorable neurological outcome included AED pad application (no or yes), first documented rhythm (ventricular fibrillation [VF] or non-VF), origins of arrest (cardiac origin or noncardiac origin), and time from call to contact with a patient by EMS personnel. In a sensitivity analysis, we built the multivariable model excluding first documented rhythm for factors associated with favorable neurological outcome, because first documented rhythm may be downstream of AED pad application and was ascertained differently between the AED pad application and non–AED pad application groups.
In addition, stratified analyses were performed by age group (<1 year vs 1-17 years)4 and by first documented rhythm (VF vs non-VF) to explore potential effect size modification in the association of AED pad application with 1-month survival with a favorable neurological outcome. All statistical analyses were performed using Stata 16/MP (StataCorp) from January to May 2026. All tests were 2-tailed, and P < .05 was considered statistically significant.
Results
During the study period, a total of 4111 pediatric patients with OHCA were registered (Figure). Among them, 3765 patients had resuscitation attempted. Of these, 3532 arrests occurred before EMS arrival. In total, 3352 patients with complete covariate data were included in the analysis. The median (IQR) age was 3 (1-4) years, and 1983 patients (59.2%) were male. Among them, 185 patients (5.5%) were in the AED pad application group, and 3167 patients (94.5%) were in the non–AED pad application group.
Figure. Flow Diagram of Pediatric Patients With Out-of-Hospital Cardiac Arrest (OHCA) in Japan, 2021-2023.
AED indicates automated external defibrillation; CPR, cardiopulmonary resuscitation; EMS, emergency medical service.
Patient characteristics with or without AED pad application are shown in Table 1. AED pad application was more commonly observed in older pediatric age groups; there were only 12 infants (6.5%) who had AED pad application. The location of arrests was most frequently at school for the AED pad application group (90 patients [48.6%]), whereas it was most frequently at home for the non–AED pad application group (2602 patients [82.2%]). Among both groups, 90 of 136 children (66.2%) had AED pad application at school and 67 of 436 children (15.4%) had AED pad application at a public location other than school. The AED pad application group had a higher proportion of receiving bystander CPR (177 patients [95.7%]). Cardiac origin was more frequently reported in the AED pad application group (114 patients [61.6%]). Regarding first documented rhythm, VF was the most common in the AED pad application group (103 patients [55.7%]), whereas asystole was the most common in the non–AED pad application group (2648 patients [83.6%]).
Table 1. Characteristics of Pediatric Patients With Out-of-Hospital Cardiac Arrest in Japan, 2021-2023.
| Characteristic | Patients, No. (%) | SMD | P valuea | ||
|---|---|---|---|---|---|
| Total (N = 3352) | AED pad application (n = 185) | No AED pad application (n = 3167) | |||
| Year | |||||
| 2021 | 1096 (32.7) | 53 (28.6) | 1043 (32.9) | .14 | .15 |
| 2022 | 1046 (31.2) | 53 (28.6) | 993 (31.4) | ||
| 2023 | 1210 (36.1) | 79 (42.7) | 1131 (35.7) | ||
| Sex | |||||
| Male | 1983 (59.2) | 127 (68.6) | 1856 (58.6) | .21 | .007 |
| Female | 1369 (40.8) | 58 (31.4) | 1311 (41.4) | ||
| Age group | |||||
| Infants (<1 y) | 1075 (32.1) | 12 (6.5) | 1063 (33.6) | .86 | <.001 |
| Younger children (1-4 y) | 551 (16.4) | 10 (5.4) | 541 (17.1) | ||
| Older children (5-12 y) | 518 (15.5) | 49 (26.5) | 469 (14.8) | ||
| Adolescents (13-17 y) | 1208 (36.0) | 114 (61.6) | 1094 (34.5) | ||
| Week time | |||||
| Weekday (Monday-Friday) | 2392 (71.4) | 136 (73.5) | 2256 (71.2) | .05 | .51 |
| Weekend (Saturday-Sunday) | 960 (28.6) | 49 (26.5) | 911 (28.8) | ||
| Time | |||||
| Daytime (9:00 AM to 4:59 PM) | 1149 (34.3) | 121 (65.4) | 1028 (32.5) | .70 | <.001 |
| Nighttime (5:00 PM to 8:59 AM) | 2203 (65.7) | 64 (34.6) | 2139 (67.5) | ||
| Location | |||||
| Home | 2623 (78.3) | 21 (11.4) | 2602 (82.2) | .84 | <.001 |
| Public area: school | 136 (4.1) | 90 (48.6) | 46 (1.5) | ||
| Public area: other | 436 (13.0) | 67 (36.2) | 369 (11.7) | ||
| Other | 157 (4.7) | 7 (3.8) | 150 (4.7) | ||
| Witness status | |||||
| None | 2421 (72.2) | 54 (29.2) | 2367 (74.7) | 1.36 | <.001 |
| Family | 552 (16.5) | 17 (9.2) | 535 (16.9) | ||
| Friends | 57 (1.7) | 9 (4.9) | 48 (1.5) | ||
| Passerby | 119 (3.6) | 13 (7.0) | 106 (3.3) | ||
| Other | 203 (6.1) | 92 (49.7) | 111 (3.5) | ||
| Bystander CPR | |||||
| None | 1129 (33.7) | 8 (4.3) | 1121 (35.4) | .77 | <.001 |
| Chest compressing only | 1941 (57.9) | 132 (71.4) | 1809 (57.1) | ||
| Rescue breathing only | 22 (0.7) | 1 (0.5) | 21 (0.7) | ||
| Chest compressions with rescue breathing | 260 (7.8) | 44 (23.8) | 216 (6.8) | ||
| Origin | |||||
| Cardiac | 1221 (36.4) | 114 (61.6) | 1107 (35.0) | .55 | <.001 |
| Noncardiac | 2131 (63.6) | 71 (38.4) | 2060 (65.0) | ||
| Dispatcher instruction during CPR | 2095 (62.5) | 105 (56.8) | 1990 (62.8) | .12 | .10 |
| First documented rhythm | |||||
| Ventricular fibrillation | 176 (5.3) | 103 (55.7)b | 73 (2.3) | 1.48 | <.001 |
| Pulseless electrical activity | 470 (14.0) | 24 (13.0) | 446 (14.1) | ||
| Asystole | 2706 (80.7) | 58 (31.4) | 2648 (83.6) | ||
| Time from call to contact with a patient by EMS personnel, median (IQR), min | 9.0 (7.0-11.0) | 9.0 (8.0-11.0) | 9.0 (8.0-11.0) | .06 | .32 |
| Time from call to hospital arrival, median (IQR), min | 31.0 (25.0-40.0) | 32.0 (26.0-43.0) | 31.0 (25.0-40.0) | .10 | .22 |
| Bystander AED shocks | 98 (2.9) | 98 (53.0) | NA | NA | NA |
| Prehospital ROSC | 234 (7.0) | 78 (42.2) | 156 (4.9) | .97 | <.001 |
| 1-mo Survival | 406 (12.1) | 97 (52.4) | 309 (9.8) | 1.04 | <.001 |
| CPC 1 or 2 | 127 (3.8) | 76 (41.1) | 51 (1.6) | 1.10 | <.001 |
Abbreviations: AED, automated external defibrillator; CPC, cerebral performance category; CPR, cardiopulmonary resuscitation; EMS, emergency medical service; NA, not applicable; ROSC, return of spontaneous circulation; SMD, standardized mean difference.
Wilcoxon rank-sum tests were applied to continuous variables, and Peason χ2 tests were applied to categorical variables.
Among these 103 patients, 5 did not receive a bystander AED shock before EMS arrival, although the AED-identified rhythm was regarded as ventricular fibrillation. They remained in ventricular fibrillation at EMS contact and received a shock by EMS personnel.
Table 2 presents the results examining factors associated with AED pad application. Arrests occurring at school were significantly associated with higher odds of AED pad application compared with those occurring in other public areas (aOR, 6.74; 95% CI, 3.73-12.21). Bystander CPR was associated with AED pad application compared with no bystander CPR (aOR, 28.69; 95% CI, 12.91-63.75). In contrast, having an arrest occur at nighttime was associated with lower odds of receiving AED pad application compared with having an arrest occur during the daytime (aOR, 0.52; 95% CI, 0.33-0.82). Infants (aOR, 0.28; 95% CI, 0.13-0.47) and young children (aOR, 0.22; 95% CI, 0.10-0.49) had lower odds of AED pad application compared with adolescents. Arrests occurring at home had lower odds of AED pad application than those occurring in other public areas (aOR, 0.06; 95% CI, 0.03-0.11). In a sensitivity analysis excluding bystander CPR (eTable 1 in Supplement 1), the associations for other factors were almost the same, but dispatcher instruction during CPR was associated with AED pad application (aOR, 2.04; 95% CI, 1.35-3.09).
Table 2. Factors Associated With AED Pad Application in Pediatric Patients With Out-of-Hospital Cardiac Arrest.
| Characteristic | Patients, No./total No. (%) | AED pad application, OR (95% CI) | |
|---|---|---|---|
| Crude | Adjusteda | ||
| Year | |||
| 2021 | 53/1096 (4.8) | 1 [Reference] | 1 [Reference] |
| 2022 | 53/1046 (5.1) | 1.05 (0.71-1.55) | 1.11 (0.63-1.95) |
| 2023 | 79/1210 (6.5) | 1.37 (0.96-1.97) | 1.56 (0.93-2.62) |
| Sex | |||
| Male | 127/1983 (6.4) | 1 [Reference] | 1 [Reference] |
| Female | 58/1369 (4.2) | 0.65 (0.47-0.89) | 0.87 (0.55-1.37) |
| Age group | |||
| Infants (<1 y) | 12/1075 (1.1) | 0.11 (0.06-0.20) | 0.28 (0.13-0.47) |
| Younger children (1-4 y) | 10/551 (1.8) | 0.18 (0.09-0.34) | 0.22 (0.10-0.49) |
| Older children (5-12 y) | 49/518 (9.5) | 1.00 (0.71-1.43) | 0.86 (0.49-1.49) |
| Adolescents (13-17 y) | 114/1208 (9.4) | 1 [Reference] | 1 [Reference] |
| Week time | |||
| Weekday (Monday-Friday) | 136/2392 (5.7) | 1 [Reference] | 1 [Reference] |
| Weekend (Saturday-Sunday) | 49/960 (5.1) | 0.89 (0.64-1.25) | 1.14 (0.71-1.83) |
| Time | |||
| Daytime (9:00 AM to 4:59 PM) | 121/1149 (10.5) | 1 [Reference] | 1 [Reference] |
| Nighttime (5:00 PM to 8:59 AM) | 64/2203 (2.9) | 0.25 (0.19-0.35) | 0.52 (0.33-0.82) |
| Location | |||
| Home | 21/2623 (0.8) | 0.04 (0.03-0.07) | 0.06 (0.03-0.11) |
| Public area: school | 90/136 (66.2) | 10.78 (6.94-16.74) | 6.74 (3.73-12.21) |
| Public area: other | 67/436 (15.4) | 1 [Reference] | 1 [Reference] |
| Other | 7/157 (4.5) | 0.26 (0.12-0.57) | 0.39 (0.15-0.98) |
| Witness status | |||
| None | 54/2421 (2.2) | 1 [Reference] | 1 [Reference] |
| Family | 17/552 (3.1) | 1.39 (0.80-2.42) | 1.50 (0.76-2.98) |
| Friends | 9/57 (15.8) | 8.22 (3.84-17.60) | 1.45 (0.51-4.09) |
| Passerby | 13/119 (10.9) | 5.38 (2.85-10.15) | 2.05 (0.90-4.66) |
| Other | 92/203 (45.3) | 36.33 (24.69-53.45) | 3.29 (1.83-5.91) |
| Bystander CPR | |||
| No | 8/1129 (0.7) | 1 [Reference] | 1 [Reference] |
| Yes | 177/2223 (8.0) | 12.12 (5.95-24.71) | 28.69 (12.91-63.75) |
| Dispatcher instruction during CPR | |||
| No | 80/1257 (6.4) | 1 [Reference] | 1 [Reference] |
| Yes | 105/2095 (5.0) | 0.78 (0.58-1.05) | 0.81 (0.51-1.29) |
Abbreviations: AED, automated external defibrillator; CPR, cardiopulmonary resuscitation; OR, odds ratio.
The explanatory variables included all variables listed in the table.
Table 3 presents the results examining factors associated with a favorable neurological outcome. AED pad application was significantly associated with an improved favorable neurological outcome (aOR, 3.11; 95% CI, 1.30-7.44). Compared with having an unwitnessed arrest, having an arrest witnessed by family members was significantly associated with improved favorable neurological outcome (aOR, 3.86; 95% CI, 2.03-3.76). Arrests presenting with VF had markedly higher odds of favorable neurological outcome (aOR, 27.49; 95% CI, 13.95-54.19) than those with non-VF. After excluding first documented rhythm from the explanatory variables (eTable 2 in Supplement 1), the association of AED pad application with a favorable neurological outcome was larger in magnitude than in the main analysis (aOR, 8.37; 95% CI, 4.06-17.22). Although the ORs for other factors changed, the direction of the associations was generally unchanged.
Table 3. Factors Associated With CPC 1 or 2 in Pediatric Patients With Out-of-Hospital Cardiac Arrest.
| Characteristic | Patients, No./total No. (%) | CPC 1 or 2, OR (95% CI) | |
|---|---|---|---|
| Crude | Adjusteda | ||
| AED pad application | |||
| No | 51/3167 (1.6) | 1 [Reference] | 1 [Reference] |
| Yes | 76/185 (41.1) | 42.60 (28.47-63.74) | 3.11 (1.30-7.44) |
| Year | |||
| 2021 | 33/1096 (3.0) | 1 [Reference] | 1 [Reference] |
| 2022 | 49/1046 (4.7) | 1.58 (1.01-2.48) | 1.80 (0.96-3.38) |
| 2023 | 45/1210 (3.7) | 1.24 (0.79-1.96) | 1.02 (0.54-1.91) |
| Sex | |||
| Male | 89/1983 (4.5) | 1 [Reference] | 1 [Reference] |
| Female | 38/1369 (2.8) | 0.61 (0.41-0.89) | 0.72 (0.42-1.22) |
| Age group | |||
| Infants (<1 y) | 13/1075 (1.2) | 0.18 (0.10-0.32) | 0.75 (0.35-1.62) |
| Younger children (1-4 y) | 5/551 (0.9) | 0.13 (0.05-0.33) | 0.49 (0.18-1.38) |
| Older children (5-12 y) | 31/518 (6.0) | 0.92 (0.60-1.42) | 1.05 (0.55-1.99) |
| Adolescents (13-17 y) | 78/1208 (6.5) | 1 [Reference] | 1 [Reference] |
| Week time | |||
| Weekday (Monday-Friday) | 97/2392 (4.1) | 1 [Reference] | 1 [Reference] |
| Weekend (Saturday-Sunday) | 30/960 (3.1) | 0.76 (0.50-1.16) | 0.80 (0.45-1.42) |
| Time | |||
| Daytime (9:00 to 4:59 PM) | 76/1149 (6.6) | 1 [Reference] | 1 [Reference] |
| Nighttime (5:00 PM to 8:59 AM) | 51/2203 (2.3) | 0.33 (0.23-0.48) | 0.81 (0.46-1.40) |
| Location | |||
| Home | 41/2623 (1.6) | 0.18 (0.11-0.28) | 0.70 (0.30-1.60) |
| Public area: school | 50/136 (36.8) | 6.46 (3.97-10.52) | 1.02 (0.45-2.31) |
| Public area: other | 36/436 (8.3) | 1 [Reference] | 1 [Reference] |
| Other | 0/157 | ||
| Witness status | |||
| None | 25/2421 (1.0) | 1 [Reference] | 1 [Reference] |
| Family | 33/552 (6.0) | 6.09 (3.59-10.34) | 3.86 (2.03-7.36) |
| Friends | 7/57 (12.3) | 13.42 (5.55-32.47) | 2.21 (0.50-9.71) |
| Passerby | 3/119 (2.5) | 2.48 (0.74-8.33) | 1.05 (0.23-4.81) |
| Others | 59/203 (29.1) | 39.27 (23.89-64.55) | 2.66 (1.13-6.27) |
| Bystander CPR | |||
| No | 16/1129 (1.4) | 1 [Reference] | 1 [Reference] |
| Yes | 111/2233 (5.0) | 3.66 (2.15-6.21) | 0.97 (0.48-1.95) |
| Origins | |||
| Cardiac origin | 98/1221 (8.0) | 1 [Reference] | 1 [Reference] |
| Noncardiac origin | 29/2131 (1.4) | 0.16 (0.10-0.24) | 0.75 (0.41-1.36) |
| Dispatcher instruction during CPR | |||
| No | 47/1257 (3.7) | 1 [Reference] | 1 [Reference] |
| Yes | 80/2095 (3.8) | 1.02 (0.71-1.48) | 1.49 (0.84-2.61) |
| First documented rhythm | |||
| VF | 96/176 (54.5) | 121.74 (76.72-193.18) | 27.49 (13.95-54.19) |
| Non-VF | 31/3176 (1.0) | 1 [Reference] | 1 [Reference] |
| Time from call to contact with patients by EMS personnel (per minute) | NA | 0.97 (0.93-1.02) | 0.95 (0.89-1.02) |
Abbreviations: AED, automated external defibrillator; CPC, cerebral performance category; CPR, cardiopulmonary resuscitation; EMS, emergency medical service; NA, not applicable; OR, odds ratio; VF, ventricular fibrillation.
The explanatory variables included all variables listed in the table.
Table 4 presents the association of AED pad application with a favorable neurological outcome, stratified by age group and first documented rhythm. Among those aged 1 to 17 years, the AED pad application group had a significantly higher rate of a favorable neurological outcome than the non–AED pad application group (aOR, 3.47; 95% CI, 1.38-8.73). Among patients aged younger than 1 year, there were no patients with a favorable neurological outcome in the AED pad application group. In the subgroup analysis stratified by the first documented rhythm, the AED pad application group showed a higher likelihood of a favorable neurological outcome than the no AED pad application group among VF arrests (aOR, 5.10; 95% CI, 1.50-17.42). No association was observed between AED pad application and a favorable neurological outcome among non-VF arrests.
Table 4. Association of AED Pad Application With CPC 1 or 2 by Age Group and First Documented Rhythm.
| Characteristic | Patients, No./total No. (%) | OR (95% CI) | |
|---|---|---|---|
| Crude | Adjusteda | ||
| Age group | |||
| <1 y | |||
| AED pad application | |||
| No | 13/1063 (1.2) | 1 [Reference] | 1 [Reference] |
| Yes | 0/12 | NC | NC |
| 1-17 y | |||
| AED pad application | |||
| No | 38/2104 (1.8) | 1 [Reference] | 1 [Reference] |
| Yes | 76/173 (43.9) | 42.60 (27.45-66.10) | 3.47 (1.38-8.73) |
| First documented rhythm | |||
| VF | |||
| AED pad application | |||
| No | 22/73 (30.1) | 1 [Reference] | 1 [Reference] |
| Yes | 74/103 (71.8) | 5.92 (3.06-11.43) | 5.10 (1.50-17.42) |
| Non-VF | |||
| AED pad application | |||
| No | 29/3094 (0.9) | 1 [Reference] | 1 [Reference] |
| Yes | 2/82 (2.4) | 2.64 (0.62-11.26) | 1.50 (0.26-8.61) |
Abbreviations: AED, automated external defibrillator; CPC, cerebral performance category; NC, not comparable; OR, odds ratio; VF, ventricular fibrillation.
These odds ratios were adjusted for year, sex, weektime, time, location, witness status, bystander cardiopulmonary resuscitation, origins, dispatcher instruction during cardiopulmonary resuscitation, and time from call to contact with a patient by emergency medical service personnel.
Discussion
In this cohort study using a nationwide registry of OHCA in Japan, we described the current landscape of AED pad application and factors associated with 1-month survival with a favorable neurological outcome among pediatric patients with OHCA (5.5%). AED pad application was performed in 185 pediatric patients with OHCA and was provided more often at school but less often at home, at night, and among infants. One-month survival with a favorable neurological outcome was significantly higher in the AED pad application group than in the non–AED pad application group. Because bystander AED shock is a downstream result of AED pad application and depends on AED rhythm analysis and shock indication, AED pad application before EMS arrival should be interpreted as a composite exposure reflecting early rhythm assessment, identification of shockable rhythm, and defibrillation when indicated. These findings could serve foundational data for formulating strategies to further increase AED pad application for pediatric patients with OHCA in typical emergency settings.
In Japan, approximately 5% of pediatric patients with OHCA received AED pad application before EMS arrival, which was lower than the 19.0% AED use before EMS arrival for pediatric OHCA from the Cardiac Arrest Registry to Enhance Survival registry in the US.15 Moreover, the proportion of AED pad application differed depending on the situation. It was high for arrests occurring at school but low for those occurring at home or at nighttime. In Japan, schools are generally equipped with at least 1 AED, and school staff have opportunities to receive regular CPR training,16,17 which could help with AED pad application for pediatric patients with OHCA at school. In contrast, for arrests occurring at home or at nighttime, AED pads may have been less likely to be applied because of limited access to AEDs. Therefore, improving access to AEDs in these situations remains an important challenge.
In this study, AED pad application before EMS arrival was associated with higher odds of 1-month survival with a favorable neurological outcome among pediatric patients with OHCA. Although the effectiveness of early defibrillation for adult patients with OHCA is well-established8,18 and AED use before EMS arrival has been associated with improved OHCA outcomes in adult patients,19,20 evidence supporting the effectiveness of AED pad application in pediatric patients with OHCA has been limited.4 Therefore, our findings reinforce efforts to further increase AED pad application for pediatric patients with OHCA. In general, the proportion of VF is lower in pediatric OHCA than in adult OHCA,21 with proportions of 5.5% in Japan from our study, 7.2% in the US15 and 6.8% in the UK.22 In our analysis, VF was the factor with the largest magnitude of association with a favorable neurological outcome in pediatric patients with OHCA. Importantly. first documented rhythm was ascertained differently between the AED pad application and non–AED pad application groups. This difference in ascertainment may be associated with the higher proportion of VF in the AED pad application group and the very large magnitude of association between VF and a favorable neurological outcome. In the analysis excluding first documented rhythm, the OR for AED pad application was larger than that in the main analysis. Nevertheless, dissemination and promotion of AED pad application for pediatric patients with OHCA might increase opportunities to identify VF earlier at the scene and increase the proportion of VF arrests that receive defibrillation before EMS arrival.
Importantly, the proportion of AED pad application in infants and younger children was lower than that in older pediatric age groups. In addition, no infants with OHCA who received an AED pad application achieved 1-month survival with a favorable neurological outcome. In a systematic review,4 the use of AED before EMS was associated with improved outcomes among pediatric patients aged 1 to 17 years; however, the effectiveness was not observed among infants aged younger than 1 year. Among infants, only 12 patients received AED pad application, and none had a favorable neurological outcome. Therefore, the association of AED pad application with a favorable neurological outcome in this group was inconclusive. Infants with OHCA are known to have poor outcomes across countries,2,23 and the effectiveness of AED pad application in this age group remains unclear. Therefore, strategies for infants with OHCA should prioritize comprehensive approaches, including the prevention of sudden infant death syndrome24 and the early recognition and activation of EMS as well as the provision of high-quality CPR by lay-rescuers.21
In this study, bystander CPR was associated with AED pad application. Because the aim of this study was to explore factors associated with AED pad application before EMS arrival, we also included implementation of bystander CPR in the multivariable model as one of prehospital factors. The AED voice prompts encourage the initiation and continuation of chest compressions,25 making CPR more likely when AED pads are applied by bystanders.26 In addition, lay rescuers who can apply AED pads may be more likely to have CPR training or prior experience.27 In the sensitivity analysis excluding bystander CPR, dispatcher instruction during CPR became associated with AED pad application, suggesting that adjustment for bystander CPR in the main model may have masked the association of dispatcher instruction with AED pad application because dispatcher instruction promotes AED pad application.28
On the other hand, although bystander CPR was associated with improved 1-month survival with a favorable neurological outcome in univariable analyses, it was not an independent factor associated with a favorable neurological outcome in the multivariable model. This finding suggests that the effect of bystander CPR was statistically diluted by the inclusion of stronger interventions (AED pad application) in the multivariable model. Importantly, these results do not deny the importance of bystander CPR. When AED pad application is not available at the scene or for non-VF arrests (which are common in pediatric patients with OHCA), bystander CPR before EMS arrival remains a critical component of the chain of survival.21 Therefore, the promotion of public-access defibrillation program focusing on the increase of both bystander CPR and AED before EMS arrival use remains essential.29
In this study, AED pad application before EMS arrival was performed in only approximately 5% of pediatric patients overall. The proportion of AED pad application differed by location; it was high at schools (66%) but low in public locations other than schools (15%). The high proportion at schools may reflect AED deployment, CPR and AED education for school staff and students, and organized emergency response systems within schools.30,31 However, AED pads were still not applied in approximately one-third of pediatric OHCAs occurring at schools, suggesting the need to further strengthen school-based efforts, such as regular CPR training to help school staff recognize cardiac arrest correctly and perform CPR and use an AED appropriately.31 In contrast, in public locations other than schools, potential barriers may include hesitation to use AEDs for children,4,21,28,32 limited knowledge regarding pediatric pads, lack of awareness of nearby AED locations, and difficulty retrieving AEDs rapidly. Because AED use at home is inherently challenging, promoting AED use in public locations other than schools is important. In nonschool settings where children gather, such as recreational facilities, swimming schools, and commercial facilities, it is important to develop public-access defibrillation programs that enable AED access and use for children.29 Given that approximately one-half of the patients with AED pad application received bystander AED shocks, promoting AED pad application may increase opportunities for early identification of shockable rhythms and defibrillation before EMS arrival.
To increase AED pad application for pediatric patients with OHCA, stronger nationwide initiatives are also needed. For example, Denmark has advanced strategic pad initiatives, such as basic life support education in schools and dispatcher-assisted CPR.33 Volunteer responder systems using smartphone applications have also been implemented.34 If similar approaches were implemented across Japan, the proportion of AED pad application for both adult and pediatric patients with OHCA could increase.
Limitations
This study has several limitations. First, information on AED pad application may be subject to misclassifications or missing data such as AED pads being applied but waveform analysis was not being performed. Second, unmeasured confounding factors may have influenced the association of AED pad application with 1-month survival with a favorable neurological outcome, such as information on location of AED deployment, skills of lay rescuers who applied the AED pads, or time from collapse to AED pad application. Third, our findings were based on Japan’s EMS system and AED availability, and attention should be paid when generalizing them to other countries. Fourth, as with all epidemiologic studies, the integrity and validity of the data, as well as ascertainment bias, are potential limitations of our study. The use of uniform data collection based on the Utstein Style guidelines for reporting cardiac arrest, the large sample size, and the population-based design should minimize these potential sources of bias.
Conclusions
In this cohort study from Japan, approximately 5% of pediatric patients with OHCA received AED pad application before EMS arrival, and AED pad application was associated with higher odds of 1-month survival with a favorable neurological outcome. These findings should be interpreted cautiously because residual confounding may remain, and first documented rhythm may have been differentially ascertained between groups. Further efforts are needed to increase AED access and use in public places where children gather (including schools) and to strengthen education and awareness of AED use for pediatric OHCA.
eMethods.
eTable 1. Factors associated with AED pad application in pediatric patients with out-of-hospital cardiac arrest excluding BCPR from the multivariable model
eTable 2. Factors associated with CPC 1 or 2 in pediatric patients with out-of-hospital cardiac arrest
eReferences.
Data sharing statement
References
- 1.Baldi E, Wnent J, Caputo ML, et al. European Resuscitation Council guidelines 2025: epidemiology in resuscitation. Resuscitation. 2025;215(suppl 1):110733. doi: 10.1016/j.resuscitation.2025.110733 [DOI] [PubMed] [Google Scholar]
- 2.Atkins DL, Everson-Stewart S, Sears GK, et al. ; Resuscitation Outcomes Consortium Investigators . Epidemiology and outcomes from out-of-hospital cardiac arrest in children: the Resuscitation Outcomes Consortium Epistry–cardiac arrest. Circulation. 2009;119(11):1484-1491. doi: 10.1161/CIRCULATIONAHA.108.802678 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Djakow J, Turner NM, Skellett S, et al. ; ERC Paediatric Life Support Writing Group collaborators . European Resuscitation Council Guidelines 2025: paediatric life support. Resuscitation. 2025;215(suppl 1):110767. doi: 10.1016/j.resuscitation.2025.110767 [DOI] [PubMed] [Google Scholar]
- 4.Atkins DL, Acworth J, Chung SP, Reis A, Van de Voorde P; International Liaison Committee on Resuscitation (ILCOR) Pediatric and Basic Life Support Task Forces . Lay rescuer use of automated external defibrillators in infants, children and adolescents: a systematic review. Resusc Plus. 2022;11:100283. doi: 10.1016/j.resplu.2022.100283 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Wyckoff MH, Greif R, Morley PT, et al. ; Collaborators . 2022 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces. Circulation. 2022;146(25):e483-e557. doi: 10.1161/CIR.0000000000001095 [DOI] [PubMed] [Google Scholar]
- 6.von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP; STROBE Initiative . The strengthening the reporting of observational studies in epidemiology (STROBE) statement: guidelines for reporting observational studies. Ann Intern Med. 2007;147(8):573-577. doi: 10.7326/0003-4819-147-8-200710160-00010 [DOI] [PubMed] [Google Scholar]
- 7.Fire and Disaster Management Agency . Current status of ambulance and rescue services: 2025 edition. Accessed February 13, 2026. https://www.fdma.go.jp/publication/rescue/post-7.html
- 8.Kitamura T, Kiyohara K, Sakai T, et al. Public-access defibrillation and out-of-hospital cardiac arrest in Japan. N Engl J Med. 2016;375(17):1649-1659. doi: 10.1056/NEJMsa1600011 [DOI] [PubMed] [Google Scholar]
- 9.Makino Y, Kiguchi T, Nishioka N, et al. Factors associated with automated external defibrillator use in out-of-hospital cardiac arrest by type of lay rescuers: a Japanese nationwide, population-based descriptive study. Resuscitation. Published online June 21, 2025. doi: 10.1016/j.resuscitation.2025.110691 [DOI] [PubMed] [Google Scholar]
- 10.Shimomura Y, Komukai S, Zha L, et al. Intra-arrest transport versus continued on-scene resuscitation in patients with out-of-hospital cardiac arrest by first documented rhythm: a nationwide cohort study using time-dependent propensity score sequential matching. Crit Care. 2025;30(1):40. doi: 10.1186/s13054-025-05811-y [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Nakao S, Katayama Y, Kitamura T, et al. Epidemiological profile of emergency medical services in Japan: a population-based descriptive study in 2016. Acute Med Surg. 2020;7(1):e485. doi: 10.1002/ams2.485 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Seizan T, Hiroyuki Y. National survey on AED sales volume and examination of systems and methods for accurately grasping AED installation numbers: National survey of AED sales and installation numbers. 2024. Health, Labour and Welfare Sciences Research Grants (Comprehensive Research on Life-Style Related Diseases including Cardiovascular Diseases and Diabetes Mellitus). Accessed February 13, 2026. https://mhlw-grants.niph.go.jp/system/files/report_pdf/R5%E5%8E%9A%E5%8A%B4%E7%A7%91%E7%A0%94%E5%9D%82%E6%9C%AC%E7%8F%AD%28AED%E7%AD%89%29%E5%A0%B1%E5%91%8A%E6%9B%B8_p13-68nb%E5%88%86%E6%8B%85_0.pdf
- 13.Japan Resuscitation Council . JRC resuscitation guidelines 2025. Accessed February 13, 2026. https://www.jrc-cpr.org/jrc-guideline-2025/
- 14.Nitta M, Iwami T, Kitamura T, et al. ; Utstein Osaka Project . Age-specific differences in outcomes after out-of-hospital cardiac arrests. Pediatrics. 2011;128(4):e812-e820. doi: 10.1542/peds.2010-3886 [DOI] [PubMed] [Google Scholar]
- 15.Naim MY, Griffis HM, Burke RV, et al. Race/ethnicity and neighborhood characteristics are associated with bystander cardiopulmonary resuscitation in pediatric out-of-hospital cardiac arrest in the United States: a study from CARES. J Am Heart Assoc. 2019;8(14):e012637. doi: 10.1161/JAHA.119.012637 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Japan School Health Association . Survey report on cardiopulmonary resuscitation and AEDs in schools. Published 2018. Accessed February 13, 2026. https://www.gakkohoken.jp/book/ebook/ebook_H300010/data/213/src/H300010.pdf
- 17.Ministry of Education . Sports, science and technology. implementation of initiatives regarding first aid such as cardiopulmonary resuscitation. Accessed February 13, 2026. https://www.mext.go.jp/a_menu/kenko/anzen/1417343_00036.htm
- 18.Bray JE, Smyth MA, Perkins GD, et al. ; Basic Life Support Task Force Collaborators . Basic life support: 2025 international liaison committee on resuscitation consensus on science with treatment recommendations. Circulation. 2025;152(16_suppl_1)(suppl 1):S34-S71. doi: 10.1161/CIR.0000000000001364 [DOI] [PubMed] [Google Scholar]
- 19.Kishimori T, Kiguchi T, Kiyohara K, et al. Public-access automated external defibrillator pad application and favorable neurological outcome after out-of-hospital cardiac arrest in public locations: a prospective population-based propensity score-matched study. Int J Cardiol. 2020;299:140-146. doi: 10.1016/j.ijcard.2019.07.061 [DOI] [PubMed] [Google Scholar]
- 20.Pollack RA, Brown SP, May S, Rea T, Kudenchuk PJ, Weisfeldt ML. Bystander automated external defibrillator application in non-shockable out-of-hospital cardiac arrest. Resuscitation. 2019;137:168-174. doi: 10.1016/j.resuscitation.2019.02.007 [DOI] [PubMed] [Google Scholar]
- 21.Scholefield BR, Acworth J, Ng KC, et al. ; Pediatric Life Support Task Force Collaborators . Pediatric life support: 2025 International Liaison Committee on Resuscitation consensus on science with treatment recommendations. Pediatrics. 2026;157(1):e2025074853. doi: 10.1542/peds.2025-074853 [DOI] [PubMed] [Google Scholar]
- 22.British Heart Foundation . Out-of-hospital cardiac arrest outcomes English ambulance services 2024: paediatric. Accessed February 13, 2026. https://warwick.ac.uk/fac/sci/med/research/ctu/trials/ohcao/publications/epidemiologyreports/ohcao_epidemiological_report_2024_paediatric_england_overview_v1.0_12.08.2025.pdf
- 23.Jayaram N, McNally B, Tang F, Chan PS. Survival after out-of-hospital cardiac arrest in children. J Am Heart Assoc. 2015;4(10):e002122. doi: 10.1161/JAHA.115.002122 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Moon RY, Carlin RF, Hand I; TASK FORCE ON SUDDEN INFANT DEATH SYNDROME AND THE COMMITTEE ON FETUS AND NEWBORN . Sleep-related infant deaths: updated 2022 recommendations for reducing infant deaths in the sleep environment. Pediatrics. 2022;150(1):e2022057990. doi: 10.1542/peds.2022-057990 [DOI] [PubMed] [Google Scholar]
- 25.Brooks SC, Clegg GR, Bray J, et al. ; International Liaison Committee on Resuscitation . Optimizing outcomes after out-of-hospital cardiac arrest with innovative approaches to public-access defibrillation: a scientific statement From the International Liaison Committee on Resuscitation. Circulation. 2022;145(13):e776-e801. doi: 10.1161/CIR.0000000000001013 [DOI] [PubMed] [Google Scholar]
- 26.Williamson LJ, Larsen PD, Tzeng YC, Galletly DC. Effect of automatic external defibrillator audio prompts on cardiopulmonary resuscitation performance. Emerg Med J. 2005;22(2):140-143. doi: 10.1136/emj.2004.016444 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Hallstrom AP, Ornato JP, Weisfeldt M, et al. ; Public Access Defibrillation Trial Investigators . Public-access defibrillation and survival after out-of-hospital cardiac arrest. N Engl J Med. 2004;351(7):637-646. doi: 10.1056/NEJMoa040566 [DOI] [PubMed] [Google Scholar]
- 28.Snow L, Whiting J, Olasveengen TM, Bray JE, Smith CM; International Liaison Committee on Resuscitation Basic Life Support Task Force . Optimization of dispatcher instruction for public-access automated external defibrillator retrieval and use: a scoping review. Resusc Plus. 2025;25:101005. doi: 10.1016/j.resplu.2025.101005 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.International Liaison Committee on Resuscitation . Public access AED Program (BLS #347): systematic review. Published February 11, 2020. Updated April 19, 2021. Accessed February 13, 2026. https://costr.ilcor.org/document/public-access-aed-program-bls-347-systematic-review
- 30.Kiyohara K, Sado J, Kitamura T, et al. Public-access automated external defibrillation and bystander-initiated cardiopulmonary resuscitation in schools: a nationwide investigation in Japan. Europace. 2019;21(3):451-458. doi: 10.1093/europace/euy261 [DOI] [PubMed] [Google Scholar]
- 31.Mitamura H, Iwami T, Mitani Y, Takeda S, Takatsuki S. Aiming for zero deaths: prevention of sudden cardiac death in schools—statement from the AED Committee of the Japanese Circulation Society. Circ J. 2015;79(7):1398-1401. doi: 10.1253/circj.CJ-15-0453 [DOI] [PubMed] [Google Scholar]
- 32.Joyner BL Jr, Dewan M, Bavare A, et al. Pediatric basic life support: 2025 American Heart Association and American Academy of Pediatrics guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2025;152(16_suppl_2)(suppl 2):S424-S447. doi: 10.1161/CIR.0000000000001370 [DOI] [PubMed] [Google Scholar]
- 33.Wissenberg M, Lippert FK, Folke F, et al. Association of national initiatives to improve cardiac arrest management with rates of bystander intervention and patient survival after out-of-hospital cardiac arrest. JAMA. 2013;310(13):1377-1384. doi: 10.1001/jama.2013.278483 [DOI] [PubMed] [Google Scholar]
- 34.Andelius L, Malta Hansen C, Lippert FK, et al. Smartphone activation of citizen responders to facilitate defibrillation in out-of-hospital cardiac arrest. J Am Coll Cardiol. 2020;76(1):43-53. doi: 10.1016/j.jacc.2020.04.073 [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
eMethods.
eTable 1. Factors associated with AED pad application in pediatric patients with out-of-hospital cardiac arrest excluding BCPR from the multivariable model
eTable 2. Factors associated with CPC 1 or 2 in pediatric patients with out-of-hospital cardiac arrest
eReferences.
Data sharing statement
