Effect of gender on out-of-hospital cardiac arrest survival: a registry-based study

Age and sex-related differences in outcomes of OHCA patients after adjustment for sex-based in-hospital management disparities

OBJECTIVES

Out-of-hospital cardiac arrest (OHCA) survival differences due to sex remain controversial. Previous studies adjusted for prehospital variables, but not sex-based in-hospital management disparities. We aimed to investigate age and sex-related differences in survival outcomes in OHCA patients after adjustment for sex-based in-hospital management disparities.

METHODS

This retrospective observational study used a prospective multicenter OHCA registry to review data of patients from October 2015 to December 2020. The primary outcome was good neurological outcome defined as cerebral performance category score 1 or 2. We performed multivariable logistic regression and restricted cubic spline analysis according to age.

RESULTS

Totally, 8988 patients were analyzed. Women showed poorer prehospital characteristics and received fewer coronary angiography, percutaneous coronary interventions, targeted temperature management, and extracorporeal membrane oxygenation than men. Good neurological outcomes were lower in women than in men (5.8% vs. 12.2%, p < 0.001). After adjustment for age, prehospital variables, and in-hospital management, women were more likely to have good neurological outcomes than men (adjusted odds ratio [aOR] 1.37, 95% confidence interval [CI] 1.07-1.74, p = 0.012). The restricted cubic spline curve showed a reverse sigmoid pattern of adjusted predicted probability of outcomes and dynamic associations of sex and age-based outcomes.

CONCLUSIONS

Women with OHCA were more likely to have good neurological outcome after adjusting for age, prehospital variables, and sex-based in-hospital management disparities. There were non-linear associations between sex and survival outcomes according to age and age-related sex-based differences.

Association between sex and survival after out-of-hospital cardiac arrest: A systematic review and meta-analysis

The current literature on sex differences in 30-day survival following out-of-hospital cardiac arrest (OHCA) is conflicting, with 3 recent systematic reviews reporting opposing results. To address these contradictions, this systematic literature review and meta-analysis aimed to synthesize the literature on sex differences in survival after OHCA by including only population-based studies and through separate meta-analyses of crude and adjusted effect estimates. MEDLINE and Embase databases were systematically searched from inception to March 23, 2022 to identify observational studies reporting sex-specific 30-day survival or survival until hospital discharge after OHCA. Two meta-analyses were conducted. The first included unadjusted effect estimates of the association between sex and survival (comparing males vs females), whereas the second included effect estimates adjusted for possible mediating and/or confounding variables. The PROSPERO registration number was CRD42021237887, and the search identified 6712 articles. After the screening, 164 potentially relevant articles were identified, of which 26 were included. The pooled estimate for crude effect estimates (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.22-1.66) indicated that males have a higher chance of survival after OHCA than females. However, the pooled estimate for adjusted effect estimates shows no difference in survival after OHCA between males and females (OR, 0.93; 95% CI, 0.84-1.03). Both meta-analyses involved high statistical heterogeneity between studies: crude pooled estimate I2 = 95.7%, adjusted pooled estimate I2 = 91.3%. There does not appear to be a difference in survival between males and females when effect estimates are adjusted for possible confounding and/or mediating variables in non-selected populations.

Sex and out-of-hospital cardiac arrest survival: a systematic review

BACKGROUND

The literature is unresolved on whether female receive advanced cardiac life support less than do male and on whether female have a survival advantage over male after cardiopulmonary resuscitation.

METHODS

We systematically searched PubMed, Embase and Web of Science databases (from inception to 23-April-2022) for papers reporting outcomes in adult male and female after out-of-hospital cardiac arrest. The main study outcome was the rate of adjusted survival to hospital discharge or 30 days. Secondary outcomes included unadjusted survival to hospital discharge and favourable neurological outcome.

RESULTS

A total of 28 studies were included, involving 1,931,123 patients. Female were older than male, their cardiac arrests were less likely to be witnessed and less likely to present with a shockable rhythm. Unadjusted analysis showed that females had a lower likelihood of survival than males (OR 0.68 [0.62-0.74], I2 = 97%). After adjustment, no significant difference was identified between male and female in survival at hospital discharge/30 days (OR 1.01 [0.93-1.11], I2 = 87%). Data showed that male had a significantly higher likelihood of favorable neurological outcome in unadjusted analysis but this trend disappeared after adjustment. Both the primary outcome (adjusted for several variables) and the secondary outcomes were associated with substantial heterogeneity. The variables examined using meta-regression, subgroup and sensitivity analyses (i.e., study type, location, years, population, quality of adjustment, risk of bias) did not reduce heterogeneity.

CONCLUSIONS

The adjusted rate of survival to hospital discharge/30 days was similar for male and female despite an initial seeming survival advantage for male. The validity of this finding is limited by substantial heterogeneity despite in-depth investigation of its causes, which raises concerns regarding latent inequalities in some reports nonetheless. Further study on this topic may require inclusion of factors not reported in the Utstein template and in-depth analysis of decision-making processes.

Out-of-hospital cardiac arrest in pregnant women: a 55-patient French cohort study

AIM

To describe a cohort of pregnant women having suffered an out-of-hospital cardiac arrest (OHCA) and to compare them with nonpregnant women of childbearing age having suffered OHCA.

METHODS

Study data were extracted from the French National OHCA Registry between 2011 and 2021. We compared patients in terms of characteristics, care and survival.

RESULTS

We included 3,645 women of childbearing age (15-44) who had suffered an OHCA; 55 of the women were pregnant. Pregnant women were younger than nonpregnant victims (30 vs. 35 years, p=0.006) and were more likely to have a medical history (76.4% vs. 50.5%, p<0.001) and a medical cause of the OHCA (85.5% vs. 57.2%, p<0.001). Advanced Life Support was more frequently administered to pregnant women (98.2%, vs. 72.0%; p<0.001). In pregnant women, the median time of MICU arrival was 20 minutes for the Medical Intensive Care Unit with no difference with nonpregnant women. Survival rate on admission to hospital was higher among pregnant women (43.6% vs. 27.3%; p=0.009). There was no difference in 30-day survival between pregnant and nonpregnant groups (14.5% vs. 7.3%; p=0.061). Fetal survival was only observed for OHCAs that occurred during the pregnancy second or third trimester (survival rates: 10.0% and 23.5%, respectively).

CONCLUSIONS

Our results show that resuscitation performance does not meet European Resuscitation Council's specific guidelines on OHCA in pregnant women. Although OHCA in pregnancy is rare, the associated prognosis is poor for both woman and fetus. Preventive measures should be reinforced, especially when pregnant women have medical history.

The association of biological sex and long-term outcomes in patients with acute dyspnea at the emergency department

BACKGROUND AND IMPORTANCE

Marked differences have been described between women and men in disease prevalence, clinical presentation, response to treatment and outcomes. However, such data are scarce in the acutely ill. An awareness of differences related to biological sex is essential for the success of clinical care and outcomes in patients presenting with acute dyspnea, the most frequent cause of emergency department (ED) admission.

OBJECTIVES

The aim of the present study was to assess the effect of biological sex on 1-year all-cause mortality in patients presenting with acute dyspnea to the ED.

DESIGN, SETTINGS AND PARTICIPANTS

Consecutive adult patients presenting with acute dyspnea in two Lithuanian EDs were included. Clinical characteristics, laboratory data and medication use at discharge were collected. Follow-up at 1 year was performed via national data registries.

OUTCOMES MEASURE AND ANALYSIS

The primary outcome of the study was 1-year all-cause mortality. Hazard ratios (HRs) for 1-year mortality according to biological sex were calculated using a Cox proportional hazards regression model, with and without adjustment for the following confounders: age, systolic blood pressure, creatinine, sodium and hemoglobin.

MAIN RESULTS

A total of 1455 patients were included. Women represented 43% of the study population. Compared to men, women were older [median (interquartile range [IQR]) age 74 (65-80) vs. 68 (59-77) years, P < 0.0001]. The duration of clinical signs before admission was shorter for women [median (IQR) duration 4 (1-14) vs. 7(2-14) days, P = 0.006]. Unadjusted 1-year all-cause mortality was significantly lower in women (21 vs. 28%, P = 0.001). Adjusted HR of 1-year all-cause mortality was lower in women when compared to men [HR 0.68 (0.53-0.88), P = 0.0028]. Additional sensitivity analyses confirmed the survival benefit for women in subgroups including age greater and lower than 75 years, the presence of comorbidities and causes of dyspnea (cardiac or noncardiac).

CONCLUSION

Women have better 1-year survival than men after the initial ED presentation for acute dyspnea. Understanding the biological sex-related differences should lead toward precision medicine, and improve clinical decision-making to promote gender equality in health.

Health inequities in out-of-hospital cardiac arrest

PURPOSE OF REVIEW

Out-of-hospital cardiac arrest (OHCA) is a time-critical emergency in which a rapid response following the chain of survival is crucial to save life. Disparities in care can occur at each link in this pathway and hence produce health inequities. This review summarises the health inequities that exist for OHCA patients and suggests how they may be addressed.

RECENT FINDINGS

There is international evidence that the incidence of OHCA is increased with increasing deprivation and in ethnic minorities. These groups have lower rates of bystander CPR and bystander-initiated defibrillation, which may be due to barriers in accessing cardiopulmonary resuscitation training, provision of public access defibrillators, and language barriers with emergency call handlers. There are also disparities in the ambulance response and in-hospital care following resuscitation. These disadvantaged communities have poorer survival following OHCA.

SUMMARY

OHCA disproportionately affects deprived communities and ethnic minorities. These groups experience disparities in care throughout the chain of survival and this appears to translate into poorer outcomes. Addressing these inequities will require coordinated action that engages with disadvantaged communities.

Gender effect in survival after out-of-hospital cardiac arrest: A nationwide, population-based, case-control propensity score matched study based Korean national cardiac arrest registry

Objective

This study aimed to describe the relationship between sex and survival of patients with out-of-hospital cardiac arrest (OHCA) and further investigate the potential impact of female reproductive hormones on survival outcomes, by stratifying the patients into two age groups.

Methods

This retrospective, national population-based observational, case-control study, included Korean OHCA data from January 1, 2009, to December 31, 2016. We used multiple logistic regression with propensity score-matched data. The primary outcome was survival-to-discharge.

Results

Of the 94,160 patients with OHCA included, 34.2% were women. Before propensity score matching (PSM), the survival-to-discharge rate was 5.2% for females and 9.1% for males, in the entire group (OR 0.556, 95% CI [–0.526–0.588], P<0.001). In the reproductive age group (age 18–44 years), the survival-to-discharge rate was 14% for females and 15.6% for males (OR 0.879, 95% CI [0.765–1.012], P = 0,072) and in the post-menopause age group (age ≥ 55 years), the survival-to-discharge rate was 4.1% for females and 7% for males (OR 0.562, 95% CI [0.524–0.603], P<0.001). After PSM (28,577 patients of each sex), the survival-to-discharge rate was 5.4% for females and 5.4% for males (OR, 1.009 [0.938–1.085], P = 0.810). In the reproductive age group, the survival-to-discharge rate was 14.5% for females and 11.5% for males (OR 1.306, 95% CI [1.079–1.580], P = 0.006) and in the post-menopause age group, the survival-to-discharge rate was 4.2% for females and 4.6% for males (OR 0.904, 95% CI [0.828–0.986], P = 0.022). After adjustment for confounders, women of reproductive age were more likely to survive at hospital discharge. However, there was no statistically significant difference in neurological outcome (OR 1.238, 95% CI [0.979–1.566], P = 0.074).

Conclusions

Females of reproductive age had a better chance of survival when matched for confounding factors. Further studies using sex hormones are needed to improve the survival rate of patients with OHCA.

Sex differences in clinical presentation and risk stratification in the Emergency Department: An observational multicenter cohort study

OBJECTIVE

The aim of this study was to investigate whether sex differences exist in disease presentations, disease severity and (case-mix adjusted) outcomes in the Emergency Department (ED).

METHODS

Observational multicenter cohort study using the Netherlands Emergency Department Evaluation Database (NEED), including patients ≥ 18 years of three Dutch EDs. Multivariable logistic regression was used to study the associations between sex and outcome measures in-hospital mortality and Intensive Care Unit/Medium Care Unit (ICU/MCU) admission in ED patients and in subgroups triage categories and presenting complaints.

RESULTS

Of 148,825 patients, 72,554 (48.8%) were females. Patient characteristics at ED presentation and diagnoses (such as pneumonia, cerebral infarction, and fractures) were comparable between sexes at ED presentation. In-hospital mortality was 2.2% in males and 1.7% in females. ICU/MCU admission was 4.7% in males and 3.1% in females. Males had higher unadjusted (OR 1.34(1.25-1.45)) and adjusted (AOR 1.34(1.24-1.46)) risks for mortality, and unadjusted (OR 1.54(1.46-1.63)) and adjusted (AOR 1.46(1.37-1.56)) risks for ICU/MCU admission. Males had higher adjusted mortality and ICU/MCU admission for all triage categories, and with almost all presenting complaints except for headache.

CONCLUSIONS

Although patient characteristics at ED presentation for both sexes are comparable, males are at higher unadjusted and adjusted risk for adverse outcomes. Males have higher risks in all triage categories and with almost all presenting complaints. Future studies should investigate reasons for higher risk in male ED patients.