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Background To clarify the impact of the 2020 COVID-19 pandemic on bystanders’ response to and outcomes of pediatric out-of-hospital cardiac arrest (OHCA)| in Japan. Methods Prospectively collected nationwide population-based data, including detailed location information, of 9,212 pediatric (age ≤ 18 years) OHCA cases recorded between 2017 and 2020 were combined with another database. After excluding 610 emergency medical service (EMS)- and physician-witnessed cases, 62 cases without any prehospital resuscitation effort, and 430 newborns, 7,582 patients were finally analyzed. The primary outcome was neurologically favorable 1-month survival (cerebral performance category = 1 or 2). We examined detailed variations in OHCA characteristics and outcomes between the pre-pandemic and pandemic years with consideration of phase, and witness status. Results The pandemic year 2020 was considerably associated with higher rates of neurologically favorable 1-month survival rate, bystander cardiopulmonary resuscitation (BCPR), advanced compliance to DA-CPR (dispatcher-assisted CPR), and higher proportions of witnessed OHCA, outdoor OHCA, and compression-only BCPR. The pandemic year was associated with a lower incidence of DA-CPR attempt in care/education facilities, and a higher incidence of DA-CPR during the temporary school closure. The association of the pandemic year with better outcomes and higher bystander’s own activities for CPR in witnessed OHCA were statistically stronger than those in unwitnessed OHCA. Improvements in the survival rate in 2020 were significant in locations other than childcare/education facilities and for witnessed OHCA and OHCA during days other than temporary school closure. Worsening of outcomes was not observed in any subgroup. he superiority of conventional BCPR to compression-only BCPR in neurologically favorable outcomes were enhanced in 2020. Conclusions The COVID-19 pandemic in 2020 was associated with better outcomes of OHCA in children. Significant enhancements of favorable outcomes were observed in witnessed cases. The heightened preparedness for health crises in communities may have contributed to better outcomes during this pandemic compared to pre-pandemic years. In addition, during this pandemic, the benefits of conventional CPR were further enhanced.

Aims Emergency medical service (EMS) may detect seizure-like activity in addition to agonal breathing in out-of-hospital cardiac arrest (OHCA). This study investigates the incidence and predictors of seizure-like activity in nontraumatic, EMS-witnessed OHCA and their association with clinical outcomes. Methods This prospective study explored EMS-recorded concomitant signs/symptoms that lead to the requirement of advanced life support in patients with nontraumatic, EMS-witnessed OHCA. Seizure-like activity includes abnormal/tonic movements and eyeball deviation. Sudden OHCA was defined by the absence of signs/symptoms of impending cardiac arrest at EMS contact or progressive circulatory/respiratory depressions after the EMS contact. Neurologically favorable outcomes were defined as the cerebral performance category score of 1 or 2 at discharge. Results From April 2012 to March 2020, 465 patients were studied. The incidence of seizure-like activity at cardiac arrest onset was 12.7% (59/465) in all patients with nontraumatic, EMS-witnessed OHCA. Seizure-like activity was common during shockable initial rhythm; in patients with “sudden” OHCA; and in patients who were younger, male, or had a presumed cardiac etiology. In a boosting tree, shockable initial rhythm, “sudden” OHCA, and presumed cardiac etiology were major factors that predicted the incidence of seizure-like activity. Multivariate logistic regression models including and excluding OHCA characteristics revealed that both seizure-like activity and agonal breathing recorded during EMS-witnessed OHCA were associated with favorable outcomes. Conclusions Seizure-like activity is a major sign/symptom of the onset of “sudden” cardiac arrest of presumed cardiac etiology, particularly in patients with shockable initial rhythms. Such activity were significantly associated with neurologically favorable outcomes.

ObjectivesDescribe the epidemiologic features of out-of-hospital cardiac arrest (OHCA) caused by anaphylaxis and identify outcome-associated factors.DesignObservational study.SettingData from the Japanese Fire and Disaster Management Agency database.ParticipantsA total of 292 patients from 879 057 OHCA events between 2013 and 2019 with OHCA caused by anaphylaxis and for whom prehospital resuscitation was attempted were included in the analysis.Outcome measuresThe incidence of anaphylaxis-induced OHCA, neurologically favourable 1-month survival, defined as cerebral performance category 1 or 2, and 1-month survival.ResultsThe proportion of OHCAs caused by anaphylaxis was high in non-elderly and male patients from July to September and during business hours. Bystander-witnessed (adjusted OR=4.43; 95% CI 1.84 to 10.7) and emergency medical service-witnessed events (adjusted OR=3.28; 95% CI 1.21 to 8.87) were associated with higher rates of neurologically favourable 1-month survival as well as better 1-month survival. Shockable initial ECG rhythms were recorded in only 19 patients (6.5%), and prehospital defibrillation was attempted in 16 such patients (84.2%). Neither shockable initial rhythms nor prehospital defibrillation was associated with better outcomes. Patients requiring advanced airway management had poor neurological outcomes (adjusted OR=0.17; 95% CI 0.07 to 0.42) and worse 1-month survival (adjusted OR=0.28; 95% CI 0.14 to 0.58).ConclusionsFew cases of OHCA were attributable to anaphylaxis. Witnessed OHCAs, particularly those witnessed by bystanders, were associated with better neurological outcomes. Airway complications requiring advanced airway management were likely associated with poor outcomes.

Objectives: This study aimed to analyse the effects of rescue breath and chest compression combinations in bystander cardiopulmonary resuscitation (BCPR) with and without dispatch-assisted CPR (DA) on the outcomes between unwitnessed and bystander-witnessed out-of-hospital cardiac arrest (OHCA).Design and Settings: This retrospective study analysed the prospectively collected data of 212,003 unwitnessed and 117,920 bystander-witnessed OHCA cases between 2014 and 2016 in Japan, with BCPR classification based on two clinical components (DA provision [with or without DA] and combination of breaths and compressions [standard or compression-only]).Main outcome measures: Neurologically favourable outcome at 1 monthResults: In univariate analysis, unwitnessed cases had no significant association of BCPR with the overall neurologically favourable outcome (provided vs not provided, 0.65% [686/106,152] vs 0.66% [694/105,851]) compared with bystander-witnessed cases (5.6% [3,538/62,814] vs 3.5% [1,911/55,106]). After BCPR classification by two clinical components, the outcome of unwitnessed cases was improved by standard BCPR with DA (0.88% [69/7,807], adjusted OR; 95% CI, 1.38; 1.05–1.81) and compression-only (1.04% [161/15,497], 1.49;1.23–1.80) and standard (1.18% [41/3,463], 1.71; 1.21–2.43) BCPR without DA, but not by compression-only BCPR with DA (0.52% [415/79,385], 0.88; 0.76–1.01). According to multivariable logistic regression analysis focusing on the two clinical components only in cases with BCPR, neurologically favourable outcomes were worse in DA provision (0.76; 0.60–0.97) but better in standard BCPR, (1.27; 1.01–1.60) without significant interaction (P = 0.16), in unwitnessed cases. In bystander-witnessed cases, DA provision was associated with better outcomes (1.27; 1.01–1.60), with significant interaction (P = 0.03).Conclusions: Compared with no BCPR, compression-only BCPR with DA does not improve the neurologically favourable outcomes, and standard BCPR without DA is ideal in unwitnessed OHCA cases. Education on standard CPR and chest compression-only CPR as an option should be maintained because numerous OHCA cases are not witnessed by bystanders.

Background: Many out-of-hospital cardiac arrest cases are unwitnessed. For both unwitnessed and witnessed cases, recent guidelines endorse the dispatcher’s instruction of compression-only cardiopulmonary resuscitation to lay rescuers without previous resuscitation training. This study aimed to investigate the changes in the composition of bystander resuscitation based on the combination of rescue breathing and dispatcher-assisted resuscitation, and the association of the changes in bystander resuscitation content with annual outcome improvement in unwitnessed out-of-hospital cardiac arrest cases.Method: Retrospective analysis of prospective national cohort study in a population-based setting. Out-of-hospital cardiac arrest cases in 2009–2016 (986,760 cases) were reviewed to provide a complete dataset for analyses (941,858 cases). Main outcome was neurologically favorable survival at 1 month.Results: Of the 941,858 cases, the rates of neurologically favorable survival adjusted for prehospital confounders continuously increased annually. When classified into 5 groups according to the contents of resuscitation, the proportions of the dispatcher-assisted compression-only resuscitation group increased annually, whereas the proportions of the other groups decreased. That is, the shift from standard (defined as the combination of chest compressions and rescue breathings) to compression-only bystander resuscitation were observed for both unwitnessed and bystander-witnessed cases. In unwitnessed cases, the survival rate of the dispatcher-assisted compression-only resuscitation group was always lower than that of the no-resuscitation group during the study period. On the other hand, the survival rate of dispatcher-assisted standard resuscitation group exceeded that of the no-resuscitation group at the end of the study period (adjusted odds ratio; 95% confidence intervals (CI), 1.41; 1.02–1.93), and the increase in survival rate was prominent compared to that of the dispatcher-assisted compression-only resuscitation group (adjusted unit odds ratio/year; 95% CI, 1.15; 1.08–1.24 vs. 1.04; 1.00–1.07).Conclusions: The proportions of dispatcher-assisted compression-only resuscitation group increased annually, but its survival rate of the neurologically favorable 1-month did not exceed compared to that of the no-resuscitation group in unwitnessed cases. The dispatcher-assisted compression-only resuscitation did not appear to be an ideal management for unwitnessed out-of-hospital cardiac arrest cases.

Objective: To investigate the impact of epinephrine on prehospital rearrest and re-attainment of prehospital return of spontaneous circulation (ROSC). Methods: Data for 9,292 (≥ 8 years) out-of-hos...

ImportanceThe effect of large-scale disasters on bystander cardiopulmonary resuscitation (BCPR) performance is unknown.ObjectiveTo investigate whether and how large-scale earthquake and tsunami as well as subsequent nuclear pollution influenced BCPR performance for out-of-hospital cardiac arrest (OHCA) witnessed by family and friends/colleagues.Design and settingRetrospective analysis of prospectively collected, nationwide, population-based data for OHCA cases.ParticipantsFrom the nationwide OHCA registry recorded between 11 March 2010 and 1 March 2013, we extracted 74 684 family-witnessed and friend/colleague-witnessed OHCA cases without prehospital physician involvement.ExposureEarthquake and tsunamis that were followed by nuclear pollution and largely affected the social life of citizens for at least 24 weeks.Main outcome and measureNeurologically favourable outcome after 1 month, 1-month survival and BCPR.MethodsWe analysed the 4-week average trend of BCPR rates in the years affected and before and after the disaster. We used univariate and multivariate logistic regression analyses to investigate whether these disasters affected BCPR and OHCA results.ResultsMultivariable logistic regression for tsunami-affected prefectures revealed that the BCPR rate during the impact phase in 2011 was significantly lower than that in 2010/2012 (42.5% vs 48.2%; adjusted OR; 95% CI 0.82; 0.68 to 0.99). A lower level of bystander compliance with dispatcher-assisted CPR instructions (62.1% vs 69.5%, 0.72; 95% CI 0.57 to 0.92) in the presence of a preserved level of voluntary BCPR performance (23.6% vs 23.8%) was also observed. Both 1-month survival and neurologically favourable outcome rates during the impact phase in 2011 were significantly poorer than those in 2010/2012 (8.5% vs 10.7%, 0.72; 95% CI 0.52 to 0.99, 4.0% vs 5.2%, 0.62; 95% CI 0.38 to 0.98, respectively).Conclusion and relevanceA large-scale disaster with nuclear pollution influences BCPR performance and clinical outcomes of OHCA witnessed by family and friends/colleagues. Basic life-support training leading to voluntary-initiated BCPR might serve as preparedness for disaster and major accidents.

The quality of acute aortic syndrome (AAS) assessment by emergency medical service (EMS) and the incidence and prehospital factors associated with 1-month survival remain unclear.We retrospectively analyzed the data collected for 94,468 patients with non-traumatic medical emergency excluding out-of-hospital cardiac arrest during the period of 2011-2014.Of these transported by EMS, 22,075 had any of the AAS-related symptoms, and 330 had an EMS-assessed risk for AAS; of these, 195 received an in-hospital AAS diagnosis. Of the remaining 21,745 patients without EMS-assessed risk, 166 were diagnosed with AAS. Therefore, the sensitivity and specificity of our EMS-risk assessment for AAS was 54.0% (195/361) and 99.4% (21,579/21,714), respectively. EMS assessed the risk less frequently when patients were elderly and presented with dyspnea and syncope/faintness. Sign of upper extremity ischemia was rarely detected (6.9%) and absence of this sign was associated with lack of EMS-assessed risk. The calculation of modified aortic dissection detection risk score revealed that rigorous assessment based on this score may increase the EMS sensitivity for AAS. The 1-month survival rate was significantly higher in patients admitted to core hospitals with surgical teams for AAS than in those admitted to all other hospitals [87.5% (210/240) vs 69.4% (84/121); P0.01]. Multiple logistic regression analysis demonstrated that Stanford type A, Glasgow coma scale ≤14, and admission to core hospitals providing emergency cardiovascular surgery were associated with 1-month survival.Improvement of AAS survival is likely to be affected by rapid admission to appropriate hospitals providing cardiovascular surgery.

ObjectiveTo investigate the association of school hours with outcomes of schoolchildren with out-of-hospital cardiac arrest (OHCA).MethodsFrom the 2005–2014 nationwide databases, we extracted the data for 1660 schoolchildren (6–17 years) with bystander-witnessed OHCA. Univariate analyses followed by propensity-matching procedures and stepwise logistic regression analyses were applied. School hours were defined as 08:00 to 18:00.ResultsThe neurologically favourable 1-month survival rate during school hours was better than that during non-school hours only on school days: 18.4% and 10.5%, respectively. During school hours on school days, patients with OHCA more frequently received bystander cardiopulmonary resuscitation (CPR) and public access defibrillation (PAD), and had a shockable initial rhythm and presumed cardiac aetiology. The neurologically favourable 1-month survival rate did not significantly differ between school hours on school days and all other times of day after propensity score matching: 16.4% vs 16.1% (unadjusted OR 1.02; 95% CI 0.69 to 1.51). Stepwise logistic regression analysis during school hours on school days revealed that shockable initial rhythm (adjusted OR 2.44; 95% CI 1.12 to 5.42), PAD (adjusted OR 3.32; 95% CI 1.23 to 9.10), non-exogenous causes (adjusted OR 5.88; 95% CI 1.85 to 20.0) and a shorter emergency medical service (EMS) response time (adjusted OR 1.15; 95% CI 1.02 to 1.32) and witness-to-first CPR interval (adjusted OR 1.08; 95% CI 1.01 to 1.15) were major factors associated with an improved neurologically favourable 1-month survival rate.ConclusionsSchool hours are not an independent factor associated with improved outcomes of OHCA in schoolchildren. The time delays in CPR and EMS arrival were independently associated with poor outcomes during school hours on school days.

Purpose To investigate the impacts of emergency calls made using mobile phones on the quality of dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) and survival from out-of-hospital cardiac arrests (OHCAs) that were not witnessed by emergency medical service (EMS). Methods In this prospective study, we collected data for 2530 DA-CPR-attempted medical emergency cases (517 using mobile phones and 2013 using landline phones) and 2980 non-EMS-witnessed OHCAs (600 using mobile phones and 2380 using landline phones). Time factors and quality of DA-CPR, backgrounds of callers and outcomes of OHCAs were compared between mobile and landline phone groups. Results Emergency calls are much more frequently placed beside the arrest victim in mobile phone group (52.7% vs. 17.2%). The positive predictive value and acceptance rate of DA-CPR in mobile phone group (84.7% and 80.6%, respectively) were significantly higher than those in landline group (79.2% and 70.9%). The proportion of good-quality bystander CPR in mobile phone group was significantly higher than that in landline group (53.5% vs. 45.0%). When analysed for all non-EMS-witnessed OHCAs, rates of 1-month survival and 1-year neurologically favourable survival in mobile phone group (7.8% and 3.5%, respectively) were higher than those in landline phone group (4.6% and 1.9%; p, Embargo Period 12 months

To compare the factors associated with survival after out-of-hospital cardiac arrests (OHCAs) among three time-distance areas (defined as interquartile range of time for emergency medical services response to patient's side).From a nationwide, prospectively collected data on 716,608 OHCAs between 2007 and 2012, this study analyzed 193,914 bystander-witnessed OHCAs without pre-hospital physician involvement.Overall neurologically favourable 1-month survival rates were 7.4%, 4.1% and 1.7% for close, intermediate and remote areas, respectively. We classified BCPR by type (compression-only vs. conventional) and by dispatcher-assisted CPR (DA-CPR) (with vs. without); the effects on time-distance area survival were analyzed by BCPR classification. Association of each BCPR classification with survival was affected by time-distance area and arrest aetiology (p0.05). The survival rates in the remote area were much higher with conventional BCPR than with compression-only BCPR (odds ratio; 95% confidence interval, 1.26; 1.05-1.51) and with BCPR without DA-CPR than with BCPR with DA-CPR (1.54; 1.29-1.82). Accordingly, we classified BCPR into five groups (no BCPR, compression-only with DA-CPR, conventional with DA-CPR, compression-only without DA-CPR, and conventional without DA-CPR) and analyzed for associations with survival, both cardiac and non-cardiac related, in each time-distance area by multivariate logistic regression analysis. In the remote area, conventional BCPR without DA-CPR significantly improved survival after OHCAs of cardiac aetiology, compared with all the other BCPR groups. Other correctable factors associated with survival were short collapse-to-call and call-to-first CPR intervals.Every effort to recruit trained citizens initiating conventional BCPR should be made in remote time-distance areas.

Japanese emergency medical services (EMS) personnel providing advance life support confirm the absence of a carotid pulse before initiating chest compressions (CCs) in adult out-of-hospital cardiac arrest (OHCA). This study aims to investigate the efficacy of a new protocol facilitating early CCs before definitive cardiac arrest in enhancing the outcomes of OHCA.The 2011 new protocol facilitated EMS to initiate CCs when the carotid pulse was weak and/or50/min in comatose adult patients with respiratory arrest (apnoea or agonal breathing) and loss of the radial pulse. During 2008-2015, we compared the neurologically favourable 1-year survival rate of EMS-witnessed OHCA and EMS-confirmed out-of-hospital respiratory arrest (OHRA) in adults before (N = 257 and 34, respectively) and after (N = 255 and 54, respectively) the implementation of the new protocol.After the new protocol, EMS initiated CCs1.5 min before definitive cardiac arrest in 31% (80/255) and 33% (18/54) of EMS-witnessed OHCA and EMS-confirmed OHRA, respectively. While the new protocol was not significantly associated with survival of EMS-confirmed OHRA, it was significantly associated with survival of EMS-witnessed OHCA: 9.0% and 14.9%, before and after, P by univariate analysis0.03; adjusted OR (95% CI) by multivariable logistic regression analysis, 2.01 (1.04-3.90). Neither early start of CCs nor the new protocol was associated with the progression to cardiac arrest in 212 cases with impending cardiac arrest.A new EMS protocol facilitating early CCs before definitive cardiac arrest was associated with higher survival of EMS-witnessed OHCA.

Purpose To investigate temporal variations in dispatcher-assisted and bystander-initiated resuscitation efforts and their association with survival after bystander-witnessed out-of-hospital cardiac arrests (OHCAs). Methods We retrospectively analyzed the neurologically favorable 1-month survival and the parameters related to dispatcher assisted cardiopulmonary resuscitation (DA-CPR) and bystander CPR (BCPR) for 227,524 OHCA patients between 2007 and 2013 in Japan. DA-CPR sensitivity for OHCAs, bystander's compliance to DA-CPR assessed by the proportion of bystanders who follow DA-CPR, and performance of BCPR measured by the rate of bystander-initiated CPR in patients without DA-CPR were calculated as indices of resuscitation efforts. Results Performance of BCPR was only similar to temporal variations in the survival (correlation between hourly paired values, R2 = 0.263, P = 0.01): a lower survival rate (3.4% vs 4.2%) and performance of BCPR (23.1% vs 30.8%) during night-time (22:00–5:59) than during non-night-time. In subgroup analyses based on interaction tests, all three indices deteriorated during night-time when OHCAs were witnessed by non-family (adjusted odds ratio, 0.73–0.82), particularly in non-elderly patients. The rate of public access defibrillation for these OHCAs markedly decreased during night-time (adjusted odds ratio, 0.49) with delayed emergency calls and BCPR initiation. Multivariable logistic regression analyses revealed that the survival rate of non-family-witnessed OHCAs was 1.83-fold lower during night-time than during non-night-time. Conclusions Dispatcher-assisted and bystander-initiated resuscitation efforts are low during night-time in OHCAs witnessed by non-family. A divisional alert system to recruit well-trained individuals is needed in order to improve the outcomes of night-time OHCAs witnessed by non-family bystanders.

Aim To determine the effectiveness of ventilations in bystander cardiopulmonary resuscitation (BCPR) and to identify the factors associated with ventilation-only BCPR. Methods From out-of-hospital cardiac arrest (OHCA) data prospectively collected from 2005 to 2011 in Japan, we extracted data for 210,134 bystander-witnessed OHCAs with complete datasets but no prehospital involvement of physician [no BCPR, 115,733; ventilation-only, 2093; compression-only, 61,075; and conventional (compressions+ventilations) BCPR, 31,233] and determined the factors associated with 1-month neurologically favourable survival using simple and multivariable logistic regression analyses. In 91,885 patients with known BCPR durations, we determined the factors associated with ventilation-only BCPR. Results The rate of survival in the no BCPR, ventilation-only, compression-only and conventional group was 2.8%, 3.9%, 4.5% and 5.0%, respectively. After adjustment for other factors associated with outcomes, the survival rate in the ventilation-only group was higher than that in the no BCPR group (adjusted OR; 95% CI, 1.29; 1.01–1.63), but lower than that in the compression-only (0.76; 0.59–0.96) or conventional groups (0.70; 0.55–0.89). Conventional CPR had the highest OR for survival in almost all OHCA subgroups. The adjusted OR (95% CI) for survival after dividing BCPR into ventilation and compression components was 1.19 (1.11–1.27) and 1.60 (1.51–1.69), respectively. Older guidelines, female sex, younger patient age, bystander-initiated CPR without instruction, early BCPR and short BCPR duration were associated with ventilation-only BCPR. Conclusions Ventilation is a significant component of BCPR, but alone is less effective than compression in improving neurologically favourable survival after OHCAs.

The aim of the study was to determine the quality of basic life support (BLS) in out-of-hospital cardiac arrests (OHCAs) receiving bystander cardiopulmonary resuscitation (CPR) and public automated external defibrillator (AED) application.From January 2006 to December 2012, data were prospectively collected from OHCA) and impending cardiac arrests treated with and without public AED before emergency medical technician (EMT) arrival. Basic life support actions and outcomes were compared between cases with and without public AED application. Interruptions of CPR were compared between 2 groups of AED users: health care provider (HCP) and non-HCP.Public AEDs were applied in 10 and 273 cases of impending cardiac arrest and non-EMT-witnessed OHCAs, respectively (4.3% of 6407 non-EMT-witnessed OHCAs). Defibrillation was delivered to 33 (13.3%) cases. Public AED application significantly improved the rate of 1-year neurologically favorable survival in bystander CPR-performed cases with shockable initial rhythm but not in those with nonshockable rhythm. Emergency calls were significantly delayed compared with other OHCAs without public AED application (median: 3 and 2 minutes, respectively; P.0001). Analysis of AED records obtained from 136 (54.6%) of the 249 cases with AED application revealed significantly lower rate of compressions delivered per minute and significantly greater proportion of CPR pause in the non-HCP group. Time interval between power on and the first electrocardiographic analysis widely varied in both groups and was significantly prolonged in the non-HCP group (P = .0137).Improper BLS responses were common in OHCAs treated with public AEDs. Periodic training for proper BLS is necessary for both HCPs and non-HCPs.

To investigate differences in chronological variations in characteristics and outcomes of out-of-hospital cardiac arrests (OHCAs) between elderly and non-elderly patients.We retrospectively analyzed bystander-witnessed OHCAs without prehospital involvement of physicians between January 2007 and December 2014 in Japan. We considered the following time periods: night-time (23:00-5:59) and non-night-time; we further divided non-night-time into dinnertime (18:00-20:29) and other non-night-time. Subsequently, we analyzed chronological variations in factors associated with OHCA survival using univariate and multivariable logistic regression analyses for unmatched and propensity-matched pairs, respectively.For elderly (≥65 years old, N = 201,073) and non-elderly (≥10,65 years old, N = 57,124) OHCA patients, survival rates were lower during night-time than during non-night-time (elderly, 2.8% vs 1.6%; non-elderly, 9.8% vs 7.7%). The trend for incidences of bystander-witnessed OHCA in the elderly showed three peaks associated with breakfast-time, lunchtime, and dinnertime. However, a transient but considerable decrease in survival rates was observed at dinnertime (1.9% at dinnertime and 3.0% during other non-night-time). OHCAs in the elderly at dinnertime were characterized by low proportions of presumed cardiac etiologies and shockable initial rhythm. However,even after adjusting for these and other factors associated with survival,survival rates were significantly lower at dinnertime than during other non-night-time for elderly OHCA patients (adjusted odds ratio, 1.29; 95% confidence interval, 1.18-1.41, with dinnertime as reference). This difference was significant even after propensity matching with significant augmentation in winter.Dinnertime, particularly in winter, is associated with lower survival in elderly OHCA patients.

Aim To determine the effect of Japanese obligatory basic life support training for new driver's license applicants on their willingness to carry out basic life support. Methods We distributed a questionnaire to 9,807 participants of basic life support courses in authorized driving schools from May 2007 to April 2008 after the release of the 2006 Japanese guidelines. The questionnaire explored the participants' willingness to perform basic life support in four hypothetical scenarios: cardiopulmonary resuscitation on one's own initiative; compression-only cardiopulmonary resuscitation following telephone cardiopulmonary resuscitation; early emergency call; and use of an automated external defibrillator. The questionnaire was given at the beginning of the basic life support course in the first 6-month term and at the end in the second 6-month term. Results The 9,011 fully completed answer sheets were analyzed. The training significantly increased the proportion of respondents willing to use an automated external defibrillator and to perform cardiopulmonary resuscitation on their own initiative in those with and without prior basic life support training experience. It significantly increased the proportion of respondents willing to carry out favorable actions in all four scenarios. In multiple logistic regression analysis, basic life support training and prior training experiences within 3 years were associated with the attitude. The analysis of reasons for unwillingness suggested that the training reduced the lack of confidence in their skill but did not attenuate the lack of confidence in detection of arrest or clinical judgment to initiate a basic life support action. Conclusions Obligatory basic life support training should be carried out periodically and modified to ensure that participants gain confidence in judging and detecting cardiac arrest.