Differential Survival for Men and Women from Out‐of‐hospital Cardiac Arrest Varies by Age: Results from the OPALS Study

• Published in: Academic emergency medicine 2014-12, Vol.21 (12), p.1503-1511
• Main Authors: Safdar, Basmah, Stolz, Uwe, Stiell, Ian G., Cone, David C., Bobrow, Bentley J., deBoehr, Melanie, Dreyer, Jonathan, Maloney, Justin, Spaite, Daniel W., Choo, Esther
• Format: Article
• Language: English
• Subjects: Age Factors; Aged; Aged, 80 and over; Arrhythmias, Cardiac - etiology; Arrhythmias, Cardiac - therapy; Cardiopulmonary Resuscitation - methods; Cardiopulmonary Resuscitation - statistics & numerical data; Discharge; Electric Countershock - methods; Electric Countershock - statistics & numerical data; Emergency medical care; Emergency Medical Services - methods; Emergency Medical Services - statistics & numerical data; Female; Gender differences; Gender Identity; Heart attacks; Humans; Male; Middle Aged; Odds Ratio; Ontario - epidemiology; Out-of-Hospital Cardiac Arrest - complications; Out-of-Hospital Cardiac Arrest - mortality; Regression Analysis; Risk Factors; Sex Characteristics; Sex Factors; Survival Analysis; Survival Rate; Time Factors
• ISSN: 1069-6563; 1553-2712
• DOI: 10.1111/acem.12540

Background The effect of sex on survival in out‐of‐hospital cardiac arrest (OHCA) is controversial. Some studies report more favorable outcomes in women, while others suggest the opposite, citing disparities in care. Whether sex predicts differential age‐specific survival is still uncertain. Objectives The objective was to study the sex‐associated variation in survival to hospital discharge in OHCA patients as well as the relationship between age and sex for predicting survival. Methods The Ontario Prehospital Advanced Life Support (OPALS) registry, collected in a large study of rapid defibrillation and advanced life support programs, is Utstein‐compliant and has data on OHCA patients (1994 to 2002) from 20 communities in Ontario, Canada. All adult OHCAs not witnessed by emergency medical services (EMS) and treated during one of the three main OPALS phases were included. Clinically significant variables were chosen a priori (age, sex, witnessed arrest, initial cardiopulmonary resuscitation [CPR], shockable rhythm, EMS response interval, and OPALS study phase) and entered into a multivariable logistic regression model with survival to hospital discharge as the outcome, with sex and age as the primary risk factors. Fractional polynomials were used to explore the relationship between age and survival by sex. Results A total of 11,479 (out of 20,695) OPALS cases met inclusion criteria and 10,862 (94.6%) had complete data for regression analysis. As a group, women were older than men (median age = 74 years vs. 69 years, p