Abstract 14172: Impact of Sex on Survival With Preserved Neurologic Function Following Out-of-Hospital Cardiac Arrest

Abstract

Introduction: Females experience worse survival than males following out-of-hospital cardiac arrest (OHCA). Proposed explanations include previous observations that females less often have an initial shockable rhythm or a witnessed arrest and less often receive bystander CPR. Methods: We utilized a prospective, population-based registry of patients experiencing OHCA responded to by EMS from 2011-2015. We included patients 18 years or older who were admitted to the hospital. Univariate comparisons were performed with chi-squared test for categorical variables and t-test for age. Additional analysis compared outcomes stratified by age > 50 years as a surrogate for menopausal status. A multivariate logistic regression model was constructed to evaluate the independent association of sex with outcomes. The primary outcome was survival to hospital discharge with Modified Rankin Score (MRS) ≤3. Results: Of 13,651 patients, 4894 were female and 8757 were male. The average age was 65 years for females and 64.2 years for males (P=0.005). Females were less likely than males to arrest in a public location (13% vs 27%; P <0.001), have bystander witnessed arrest (48% vs 57%; P <0.001), receive bystander CPR (44% vs 49%; P <0.001), have an initial shockable rhythm (29% vs 48%; P <0.001), have achieved ROSC upon ED arrival (76% vs 78%; P=0.014), have an ED arrival time less than 30 minutes from dispatch call (10% vs 12% P=0.008). Among males, 27% had a favorable outcome compared to 16% of females (P <0.0001). Among individuals of age ≤ 50 years, 31% of males and 26% of females had a favorable outcome (P= 0.004). Among those of age > 50 years, 26% of males and 14% of females had a favorable outcome (P <0.0001). After adjustment for differences in age and presentation, female sex was found to be independently associated with lower rates of survival with intact neurologic function (OR 0.79, 95% CI 0.71-0.89, P =0.0001). Conclusions: Compared to males, females have less favorable OHCA presentations and worse survival to hospital discharge with preserved neurologic function. However, even after adjustment for the differences in presentation, female sex remains a significant predictor of worse survival with preserved neurologic function.