Sex differences in out-of-hospital cardiac arrest interventions within the province of British Columbia, Canada

Sex disparities in bystander defibrillation for out-of-hospital cardiac arrest

Background

Previous studies have suggested that females experiencing out-of-hospital cardiac arrest (OHCA) receive lower rates of both bystander cardiopulmonary resuscitation (CPR) and defibrillation compared to males. Whether this disparity has improved over time is unknown.

Methods

A state-wide OHCA registry in Victoria, Australia collected data over twenty years (2002-2021) regarding rates of bystander interventions in OHCA. Characteristics and outcomes of each OHCA were compared with logistic regression according to sex and time (defined in two-year periods).

Results

32,502 OHCAs were included (69.7% male). Both bystander CPR and defibrillation rates increased for females over time (p < 0.0001). There was no sex disparity in receipt of bystander CPR after adjustment for baseline differences. Females were less likely than males to receive bystander defibrillation, with sex disparity increasing from 2010 onwards (adjOR 0.26 (95%CI 0.09-0.80) in 2020-21 for females compared to males).

Conclusion

Initiatives to increase bystander CPR and defibrillation have resulted in higher overall rates of bystander interventions in the last two decades and no significant sex differences in provision of bystander CPR. However, females receive less bystander defibrillation than males, and sex disparity is increasing. Strategies to promote bystander defibrillation in females experiencing OHCA with a shockable rhythm should be a priority.

Association of sex with post-arrest care and outcomes after out-of-hospital cardiac arrest of initial shockable rhythm: a nationwide cohort study

Background

Research has described differences in the provision of prehospital treatment for women who experience out-of-hospital cardiac arrest. However, studies have reported conflicting results regarding survival outcomes or in-hospital interventions between sexes. Thus, this study aimed to investigate the association of sex with survival outcomes and in-hospital treatments in Japan.

Methods

We retrospectively analyzed data from the Japanese Association for Acute Medicine-Out-of-Hospital Cardiac Arrest Registry. Patients aged ≥18 years who presented with a shockable rhythm at the scene between June 2014 and December 2020 were included in our analysis. Outcome measures were 30-day survival and in-hospital interventions. We compared the outcomes between the sexes using multivariable logistic regression.

Results

In total, 5,926 patients (4,270 men; 1,026 women) with out-of-hospital cardiac arrest were eligible for our analysis. The proportions of patients with 30-day survival outcomes were 39.5% (1685/4,270) and 37.4% (384/1,026) in the male and female groups, respectively (crude odds ratio, 0.92; 95% confidence interval, 0.80-1.06). Although there were no significant differences, survival outcomes tended to be better in women than in men in the multiple regression analysis (adjusted odds ratio: 1.38; 95% confidence interval: 0.82-2.33). Furthermore, there was no significant difference between the sexes in terms of patients who received extracorporeal cardiopulmonary resuscitation (adjusted odds ratio: 0.81; 95% confidence interval: 0.49-1.33) or targeted temperature management (adjusted odds ratio: 0.99; 95% confidence interval: 0.68-1.46).

Conclusions

After adjusting for prognostic factors, there were no differences in survival rates and in-hospital interventions between men and women.

Provision of bystander CPR for out-of-hospital cardiac arrest in the Middle East: a retrospective gender-based analysis

BACKGROUND

Previous studies conducted in North America, Europe, and East Asia (Liu et al., EClinicalMedicine 44:101293, 2022; Matsui et al., JAMA Netw Open 2:e195111, 2019; Awad et al., J Am Coll Emerg Physicians Open 4:e12957, 2023; Yoon et al., Prehosp Emerg Care :1-7, 2022) reported gender disparities in the provision of bystander CPR for patients with out-of-hospital cardiac arrest (OHCA). However, it remains unknown whether similar disparities exist in the Middle Eastern and Gulf regions. The primary objective of this study is to evaluate gender differences in the provision of bystander CPR for patients with OHCA in Qatar.

METHODS

Retrospective analysis of data obtained from Hamad Medical Corporation OHCA registry in the State of Qatar (2016-2022). We included adults with non-traumatic and EMS-attended OHCA. We used multilevel logistic regression to examine the association between gender and provision of bystander CPR.

RESULTS

In total, 4283 patients were included. Of those, 3414 (79.7%) were males, 1639 (38.3%) arrested in public locations, and 1463 (34.2%) received bystander CPR. Unadjusted comparisons showed that females were significantly older than males (mean age: 62.2 vs. 52.7). Females had a lower proportion of OHCA occurring in public locations (15.1% vs. 44.2%) and a lower proportion of shockable rhythm (11.9 vs. 27.5%). Regarding the outcome variable (provision of bystander CPR), the unadjusted analysis showed that the proportion of females who received bystander CPR was lower than that of males (29.2% vs. 35.4%, p < 0.001). However, after adjustment, we found no significant difference in provision of bystander CPR by gender (adjusted OR female vs. male 0.99, 95% CI 0.84-1.20, p = 0.97). In the subgroup who arrested in public locations, the analysis revealed females had greater odds of receiving bystander CPR (adjusted OR female vs. male 1.47, 95% CI 1.10-1.82, p = 0.04).

CONCLUSIONS

Overall, bystander CPR was less common in female gender; after adjustment for other covariates, including arrest location, we found no significant gender differences in provision of bystander CPR. We also observed that females were found to have a lower incidence of cardiac arrest in public locations. Nevertheless, if females were to experience cardiac arrest in a public location, they would be more likely to receive CPR. Further research is required to explain the observed differences in provision of bystander CPR.

One-year survival after out-of- hospital cardiac arrest: Sex-based survival analysis in a Canadian population

Objective

We investigated sex differences in 1-year survival in a cohort of patients who survived out-of-hospital cardiac arrest (OHCA) to hospital discharge. We hypothesized that female sex is associated with higher 1-year posthospital discharge survival.

Methods

A retrospective analysis of linked data (2011-2017) from clinical databases in British Columbia (BC) was conducted. We used Kaplan-Meier curves, stratified by sex, to display survival up to 1-year, and the log-rank test to test for significant sex differences. This was followed by multivariable Cox proportional hazards analysis to investigate the association between sex and 1-year mortality. The multivariable analysis adjusted for variables known to be associated with survival, including variables related to OHCA characteristics, comorbidities, medical diagnoses, and in-hospital interventions.

Results

We included 1278 hospital-discharge survivors; 284 (22.2%) were female. Females had a lower proportion of OHCA occurring in public locations (25.7% vs. 44.0%, P < 0.001), a lower proportion with a shockable rhythm (57.7% vs. 77.4%, P < 0.001), and fewer hospital-based acute coronary diagnoses and interventions. One-year survival for females and males was 90.5% and 92.4%, respectively (log-rank P = 0.31). Unadjusted (hazard ratio [HR] males vs. females 0.80, 95% confidence interval [CI] 0.51-1.24, P = 0.31) and adjusted (HR males vs. females 1.14, 95% CI 0.72-1.81, P = 0.57) models did not detect differences in 1-year survival by sex.

Conclusion

Females have relatively unfavorable prehospital characteristics in OHCA and fewer hospital-based acute coronary diagnoses and interventions. However, among survivors to hospital discharge, we found no significant difference between males and females in 1-year survival, even after adjustment.

Impact of Awareness Time Interval on the Effect of Bystander Cardiopulmonary Resuscitation on Out-of-Hospital Cardiac Arrest: A Nationwide Study

PURPOSE

The awareness time interval (ATI), the time from the witnessed event to emergency medical service (EMS) activation, is an important factor influencing out-of-hospital cardiac arrest (OHCA) outcomes. Since bystander cardiopulmonary resuscitation (BCPR) is provided after cardiac arrest is recognized, the effect of BCPR may vary depending on ATI delay. We aimed to investigate whether ATI modifies the effect of BCPR on OHCA outcomes.

MATERIALS AND METHODS

A population-based observational study was conducted with EMS-treated witnessed adult (≥18 years) OHCAs between 2013 and 2018. The exposure variable was provision of BCPR. The primary outcome was a good neurological outcome defined as cerebral performance category scale 1or 2 (good CPC). Multivariable logistic regression analysis was conducted using the ATI group (-1, 1-5, 5- min) as the interaction term.

RESULTS

Of 34366 eligible OHCAs, 65.5% received BCPR. EMS was activated within 1 min in 45.9%, within 1-5 min in 29.2%, and after 5 min in 24.9% cases. In the adjusted interaction model, compared with no BCPR, a longer ATI resulted in smaller adjusted odds ratios for good CPC in the BCPR group [5.33 (4.17-6.82) for ATI ≤1 min, 5.14 (4.00-6.60) for 1-5 min, and 2.14 (1.63-2.81) for ATI >5 min].

CONCLUSION

The effect of BCPR on improving the chances for a good neurological outcome decreased as time from collapse to EMS activation increased. The importance of early recognition of OHCA and EMS activation should be emphasized in BCPR training.

Sex disparities in prehospital advanced cardiac life support in out-of-hospital cardiac arrests in Japan

OBJECTIVE

Sex disparities in out-of-hospital cardiac arrest (OHCA) care processes have been reported. This study aimed to investigate the association between sex and prehospital advanced cardiac life support (ACLS) interventions provided by emergency medical services in Japan.

METHODS

We analyzed data from January 1, 2013, to December 31, 2020, from the All-Japan Utstein Registry of patients with OHCA aged ≥18 years who were resuscitated by bystanders. The primary outcomes were prehospital ACLS interventions, including advanced airway management (AAM) and epinephrine administration. Sex-based disparities in receiving prehospital ACLS interventions were assessed via multivariable logistic regression analyses.

RESULTS

Among 314,460 eligible patients, females with OHCA received fewer prehospital ACLS interventions than males: 83,571/187,834 (44.5%) males vs. 55,086/126,626 (43.5%) females (adjusted odds ratio [AOR] = 0.94, 95% confidence interval [CI] = 0.93-0.96) for AAM and 60,097/187,834 (32.0%) males vs. 35,501/126,626 (28.0%) females (AOR = 0.84, 95% CI = 0.83-0.85) for epinephrine administration. Similar results were also obtained in the subgroup analysis (groups included patients aged 18-74 years and ≥75 years and those with cardiac origin, ventricular fibrillation (VF), non-VF, non-family member witnessed, and family member witnessed).

CONCLUSION

Compared with males, females were less likely to receive prehospital ACLS. Emergency medical service staff must be made aware of this disparity, and off-the-job training on intravenous cannulation or AAM replacement must be conducted. Investigation of the impact of sex disparity on OHCA care processes can facilitate planning of future public health policies to improve survival outcomes.

Predictors of neurological outcome after out-of-hospital cardiac arrest: sex-based analysis: do males derive greater benefit from hypothermia management than females?

Background

Previous studies of the effect of sex on after out-of-hospital cardiac arrest (OHCA) outcomes focused on survival to hospital discharge and 1-month survival. Studies on the effect of sex on neurological function after OHCA are still limited. The objective of this study was to identify the predictors of favorable neurological outcome and to examine the association between sex as a biological variable and favorable neurological outcome OHCA.

Methods

Retrospective analyses of clustered data from the Resuscitation Outcomes Consortium multi-center randomized controlled trial (2011–2015). We included adults with non-traumatic OHCA and EMS-attended OHCA. We used multilevel logistic regression to examine the association between sex and favorable neurological outcomes (modified Rankin Scale) and to identify the predictors of favorable neurological outcome.

Results

In total, 22,416 patients were included. Of those, 8109 (36.2%) were females. The multilevel analysis identified the following variables as significant predictors of favorable neurological outcome: younger age, shorter duration of EMS arrival to the scene, arrest in public location, witnessed arrest, bystander CPR, chest compression rate (CCR) of 100–120 compressions per minute, induction of hypothermia, and initial shockable rhythm. Two variables, insertion of an advanced airway and administration of epinephrine, were associated with poor neurological outcome. Our analysis showed that males have higher crude rates of survival with favorable neurological outcome (8.6 vs. 4.9%, p < 0.001). However, the adjusted rate was not significant. Further analyses showed that hypothermia had a significantly greater effect on males than females.

Conclusions

Males had significantly higher crude rates of survival with favorable neurological outcome. However, the adjusted rate was not statistically significant. Males derived significantly greater benefit from hypothermia management than females, but this can possibly be explained by differences in arrest characteristics or in-hospital treatment. In-depth confirmatory studies on the hypothermia effect size by sex are required.

Globally, GDP Per Capita Correlates Strongly with Rates of Bystander CPR

Introduction:

Bystander CPR is vital in improving outcomes for out-of-hospital cardiac arrest. There has been ample literature describing disparities in bystander CPR within specific countries, such as the United States, Australia, and the Netherlands. However, there has not been significant literature describing such disparities between countries.

Methods:

We examined various studies published between 2000 and 2021 that reported rates of bystander CPR in various countries. These bystander CPR rates were correlated with the GDP per capita of that country during the time the study was conducted. The correlation between GDP per capita and rates of bystander CPR was assessed.

Results:

A total of 29 studies in 35 communities across 25 countries were examined. Reported rates of bystander CPR ranged from 1.3% to 72%. From this, a strong and significant correlation between GDP per capita and rates of bystander CPR was apparent; 0.772 (p < .01), r² = 0.596.

Conclusions:

GDP per capita can be thought of as a composite endpoint that takes into account various aspects of a country’s social and economic well-being. Socioeconomically-advantaged communities likely have a better ability to provide CPR education to community members, and our findings mirror localized analyses comparing socioeconomic status and rates of bystander CPR. Future studies should continue to elucidate transnational disparities in cardiac arrest, and efforts should be directed at providing CPR education to communities with low rates of bystander CPR; low-and-middle-income countries may represent attractive targets for such interventions. However, it may be possible that rates of bystander CPR may not improve unless significant upstream improvements to socioeconomic factors take place.

Premenopausal-aged females have no neurological outcome advantage after out-of-hospital cardiac arrest: A multilevel analysis of North American populations

AIM

We investigated the impact of premenopausal age on neurological function at hospital discharge in patients with out-of-hospital cardiac arrest (OHCA). We hypothesized that premenopausal-aged females (18-47 years of age) with OHCA would have a higher probability of survival with favourable neurological function at hospital discharge compared with males of the same age group, older males, and older females (>53 years of age).

METHODS

Retrospective analyses of data from the Resuscitation Outcomes Consortium multi-center randomized controlled trial (June 2011-May 2015). We included adults with non-traumatic OHCA treated by emergency medical service. We stratified the cohort into four groups by age and sex: premenopausal-aged females (18-47 years of age), older females (≥53 years old), younger males (18-47 years of age), and older male. We used multilevel logistic regression to examine the association between age-sex and favourable neurological outcomes (modified Rankin Scale ≤ 3).

RESULTS

In total, 23,725 patients were included: 1050 (4.5%) premenopausal females; 1930 (8.1%) younger males; 7569 (31.9%) older females; and 13,176 (55.5%) older males. The multilevel analysis showed no difference in neurological outcome between younger males and younger females (OR 0.95, 95% CI 0.69-1.32, p = 0.75). Both older females (OR 0.36, 95% CI 0. 0.26-0.48, p < 0.001) and older males (OR 0.52, 95% CI 0.39-0.69, p < 0.001) had a significantly lower odds of favourable neurological outcome than younger females. Among all groups, older females had the worst outcomes.

CONCLUSIONS

We did not detect an association between premenopausal age and survival with good neurological outcome, suggesting females sex hormones do not impact OHCA outcomes. Our findings are not in line with results from other studies. Studies that rigorously evaluate menopausal status are required to definitively assess the impact of female sex hormones on outcomes.

Higher 1-year mortality in women admitted to intensive care units after cardiac arrest: A nationwide overview from the Netherlands between 2010 and 2018

PURPOSE

We study sex differences in 1-year mortality of out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA) patients admitted to the intensive care unit (ICU).

DATA

A retrospective cohort analysis of OHCA and IHCA patients registered in the NICE registry in the Netherlands. The primary and secondary outcomes were 1-year and hospital mortality, respectively.

RESULTS

We included 19,440 OHCA patients (5977 women, 30.7%) and 13,461 IHCA patients (4889 women, 36.3%). For OHCA, 1-year mortality was 63.9% in women and 52.6% in men (Hazard Ratio [HR] 1.28, 95% Confidence Interval [95% CI] 1.23-1.34). For IHCA, 1-year mortality was 60.0% in women and 57.0% in men (HR 1.09, 95% CI 1.04-1.14). In OHCA, hospital mortality was 57.4% in women and 46.5% in men (Odds Ratio [OR] 1.42, 95% CI 1.33-1.52). In IHCA, hospital mortality was 52.0% in women and 48.2% in men (OR 1.11, 95% CI 1.03-1.20).

CONCLUSION

Women admitted to the ICU after cardiac arrest have a higher mortality rate than men. After left-truncation, we found that this sex difference persisted for OHCA. For IHCA we found that the effect of sex was mainly present in the initial phase after the cardiac arrest.

The effect of sex and age on return of spontaneous circulation and survival to hospital discharge in patients with out of hospital cardiac arrest: A retrospective analysis of a Canadian population

OBJECTIVES

We evaluated the effect of sex and age on out-of-hospital cardiac arrest (OHCA) outcomes in a Canadian population.

METHODS

This study was a retrospective analysis of the British Columbia (BC) Cardiac Arrest Registry (2011-16). We included adult, non-traumatic, EMS-treated OHCA. We stratified the cohort into four groups by age and sex: younger females (18-47 years of age), younger males (18-47 years of age), older females, and older males (>53 years old). We used logistic regression to examine the effect of sex and interaction effect of sex and age on ROSC and survival to hospital discharge.

RESULTS

We included 8115 patients; 31.4% were females. Females had a lower proportion of OHCA in public locations, bystander witnessed arrests, and with initial shockable rhythms. Overall, females had greater adjusted odds of ROSC (OR 1.29, 95% CI 1.15-1.42, p < 0.001). The ROSC advantage was significant in females with non-shockable rhythms (OR 1.48, 95% CI 1.24-1.78, p < 0.001) and females of premenopausal age. However, there was no significant difference in survival to hospital discharge between females and males overall or by sex-age groups. Both younger females and younger males have higher odds of survival to hospital discharge compared to older females and males. Older females had the lowest survival rate among all other sex-age groups.

CONCLUSIONS

Female sex was associated with ROSC but not survival to hospital discharge. In the post-arrest phase, females, specifically those in the older age group, had a higher death rate, demonstrating the need for sex- and age-specific research in pre-and-post-OHCA care.

Association between sex and mortality in adults with in-hospital and out-of-hospital cardiac arrest: A systematic review and meta-analysis

OBJECTIVES

Conflicting data exists regarding the association between sex and mortality in adults with in-hospital (IHCA) and out-of-hospital cardiac arrest (OHCA). We therefore conducted a meta-analysis to investigate the association between sex and mortality in adults with IHCA and OHCA.

METHODS

We systematically searched MEDLINE and Cochrane databases to identify studies reporting sex-specific mortality in adults following IHCA or OHCA from inception to April 2020. Data were pooled using random-effects models. The primary outcome of interest was in-hospital (or 30-day) all-cause mortality.

RESULTS

We included 21 observational studies with a total of 1,029,978 adult patients - 622,085 men and 407,893 women. Seven studies included patients only with IHCA and 14 studies included patients only with OHCA. Female sex was associated with significantly higher mortality following OHCA [odds ratio (OR) 1.56, 95% confidence interval (CI) 1.32-1.84, p < 0.001) and a trend toward higher mortality following IHCA (OR 1.10, 95%CI 1.00-1.20, p = 0.052).

CONCLUSIONS

In adults with cardiac arrest, female sex was associated with significantly higher mortality following OHCA and a trend toward higher mortality following IHCA.