Traditional variables used to explain survival following out-of-hospital cardiac arrest (OHCA) account for only 72% of survival, suggesting that other unknown factors may influence outcomes. Research on other diseases suggests that neighbourhood factors may partly determine health outcomes. Yet, this approach has rarely been used for OHCA. This work outlines a methodology to investigate multiple neighbourhood factors as determinants of OHCA outcomes.

A retrospective, observational cohort study design will be used. All adult non-emergency medical service witnessed OHCAs of cardiac etiology within the city of Toronto between 2006 and 2010 will be included. Event details will be extracted from the Toronto site of the Resuscitation Outcomes Consortium Epistry—Cardiac Arrest, an existing population-based dataset of consecutive OHCA patients. Geographic information systems technology will be used to assign patients to census tracts. Neighbourhood variables to be explored include the Ontario Marginalization Index (deprivation, dependency, ethnicity, and instability), crime rate, and density of family physicians. Hierarchical logistic regression analysis will be used to explore the association between neighbourhood characteristics and 1) survival-to-hospital discharge, 2) return-of-spontaneous circulation at hospital arrival, and 3) provision of bystander cardiopulmonary resuscitation (CPR). Receiver operating characteristics curves will evaluate each model’s ability to discriminate between those with and without each outcome.

This study will determine the role of neighbourhood characteristics in OHCA and their association with clinical outcomes. The results can be used as the basis to focus on specific neighbourhoods for facilitating educational interventions, CPR awareness programs, and higher utilization of automatic defibrillation devices.

Drowning is a major public health concern, yet little is known about the characteristics of drowning patients. The objectives of this study were to describe the demographic and clinical characteristics of out-of-hospital cardiac arrest (OHCA) attributed to drowning in Ontario and to compare the characteristics of OHCA attributed to drowning to those of presumed cardiac etiology.

A retrospective, observational study was carried out of consecutive OHCA patients of drowning etiology in Ontario between August 2006 and July 2011. Bivariate analysis was used to evaluate differences between drowning and presumed cardiac etiologies.

A total of 31,763 OHCA patients were identified, and 132 (0.42%) were attributed to drowning. Emergency medical services treated 98 patients, whereas the remaining 34 met the criteria for legislative death. Overall, 5.1% of drowning patients survived to hospital discharge. When compared to patients of presumed cardiac etiology, drowning patients were younger and their arrest was more likely to be unwitnessed, present with a nonshockable initial rhythm, occur in a public location, and receive bystander cardiopulmonary resuscitation (CPR). A nonsignificant trend was noted for drowning cases to more frequently have a public access AED applied. There were no significant differences in the gender ratio or paramedic response times. Drowning patients were more likely to be transported to hospital but had a trend to be less likely to arrive with a return of spontaneous circulation. They were also more likely to be admitted to hospital but had no difference in survival to hospital discharge.

Significant differences exist between OHCA of drowning and presumed cardiac etiologies. Most drownings are unwitnessed, occur in public locations, and present with nonshockable initial rhythms, suggesting that treatment should focus on bystander CPR. Future initiatives should focus on strategies to improve supervision in targeted locations and greater emphasis on bystander-initiated CPR, both of which may reduce drowning mortality.

Bystander resuscitation efforts, such as cardiopulmonary resuscitation (CPR) and use of an automatic external defibrillator (AED), save lives in cardiac arrest cases. School training in CPR and AED use may increase the currently low community rates of bystander resuscitation. The study objective was to determine the rates of CPR and AED training in Toronto secondary schools and to identify barriers to training and training techniques.

This prospective study consisted of telephone interviews conducted with key school staff knowledgeable about CPR and AED teaching. An encrypted Web-based tool with prespecified variables and built-in logic was employed to standardize data collection.

Of 268 schools contacted, 93% were available for interview and 83% consented to participate. Students and staff were trained in CPR in 51% and 80% of schools, respectively. Private schools had the lowest training rate (39%). Six percent of schools provided AED training to students and 47% provided AED training to staff. Forty-eight percent of schools had at least one AED installed, but 25% were unaware if their AED was registered with emergency services dispatch. Cost (17%), perceived need (11%), and school population size (10%) were common barriers to student training. Frequently employed training techniques were interactive (32%), didactic instruction (30%) and printed material (16%).

CPR training rates for staff and students were moderate overall and lowest in private schools, whereas training rates in AED use were poor in all schools. Identified barriers to training include cost and student population size (perceived to be too small to be cost-effective or too large to be implemented). Future studies should assess the application of convenient and cost-effective teaching alternatives not presently in use.