Trends in short- and long-term survival among out-of-hospital cardiac arrest patients alive at hospital arrival

Abstract

Background: Out-of-hospital cardiac arrest (OHCA) is associated with a poor prognosis and poses a significant burden to the healthcare system, but few studies have evaluated whether OHCA incidence and survival have changed over time.

Methods and results: A population-based cohort study was conducted, including 34 291 OHCA patients >20 years of age who were transported alive to the emergency department of an acute-care hospital from April 1, 2002, to March 31, 2012, in Ontario, Canada. Patients with life-threatening trauma and those who died before hospital arrival were excluded. The overall age- and sex-standardized incidence of OHCA patients who were transported alive was 36 cases per 100 000 persons and did not significantly change over the study period. Cardiac risk factor prevalence increased significantly, whereas the rate of most cardiovascular conditions decreased significantly. The 30-day survival improved from 9.4% in 2002 to 13.6% in 2011; 1-year survival improved from 7.7% to 11.8% (P<0.001). Patients hospitalized in 2011 were significantly more likely to survive 30 days (adjusted odds ratio, 1.47 [95% CI, 1.22-1.77]) and 1 year (adjusted odds ratio, 1.55 [95% CI, 1.27-1.91]) compared with 2002. A significant interaction between temporal trends in survival improvement and age group was observed in which the improvement in survival was largest in the youngest age groups.

Conclusions: OHCA patients who were transported alive are increasingly likely to have cardiovascular risk factors but less likely to have previous cardiovascular conditions. The overall incidence of OHCA patients transported to hospital alive did not change over the past decade. Short- and longer-term survival after OHCA has substantially improved, with younger patients experiencing the greatest improvement.

Keywords: out-of-hospital cardiac arrest; survival; trends.