One-year survival after in-hospital cardiac arrest: A systematic review and meta-analysis.

Introduction: In-hospital cardiac arrest is a major adverse event with an incidence of 1-6/1000 admissions. It has been poorly researched and data on survival is limited. The outcome of interest in IHCA research is predominantly survival to discharge, however recent guidelines warrant for more long-term outcomes. In this systematic review we sought to quantitatively summarize one-year survival after in-hospital cardiac arrest.

Methods: For this systematic review and meta-analysis we performed a systematic search of all published data on one-year survival after IHCA up to March 9th, 2018. Results of the meta-analyses are presented as pooled proportions with corresponding 95% prediction intervals (95%PI). Between-study heterogeneity was assessed using I statistic and the DerSimonian-Laird estimator for τ. Subgroup analyses were performed for cardiac and non-cardiac patients.

Results: We included 40 studies in our systematic review and meta-analysis. The pooled one-year survival after in-hospital cardiac arrest was 13.4% (95%PI: 5.6-28.8%, I = 100%). Subgroup analysis of cardiac patients revealed a one-year survival of 39.3% (16.1%-68.6%) in patients with a non-cardiac admission characteristic one-year survival was 10.7% (4.4%-23.6%). These data cover the period 1985-2018 and show a modest change in survival over that period (10-year OR: 1.70, 95% CI: 1.04-2.76).

Discussion: One-year survival after in-hospital cardiac arrest is poor. Survival is higher in patients admitted to cardiac wards. The time trend between 1985-2018 has shown a modest improvement in one-year survival rates. Research into IHCA population characteristics might elicit the issue of heterogeneity and stagnated survival over the past decades.