In-hospital vs. out-of-hospital cardiac arrest: patient characteristics and survival


In-hospital vs. out-of-hospital cardiac arrest: patient characteristics and survival      


To compare patient characteristics, events characteristics, and outcomes for in-hospital- and out-of-hospital cardiac arrest patients in Denmark


The study was an observational cohort study including patients with in-hospital- and out-of-hospital cardiac arrest in Denmark. The primary data sources were two nationwide, prospective registries: The Danish In-Hospital Cardiac Arrest Registry (DANARREST) and the Danish Cardiac Arrest Registry. Additional information was obtained from the Danish Civil Registration System, the Danish National Patient Registry, and the National Prescription Registry. In the study we included adults (≥18 years) with an index cardiac arrest from January 1, 2017 to December 31, 2018. Data from the registries were linked using the unique Civil Personal Registration (CPR) number assigned to all Danish citizens


The primary endpoint in this study was 30-day survival. Secondary outcomes were return of spontaneous circulation (ROSC) and one-year survival


Cardiac arrests are often categorized into two separate groups in in-hospital cardiac arrest and out-of-hospital cardiac arrest. This distinction dates back decades and is based on anticipated differences in patient characteristics, provider characteristics, and timing of interventions. Despite this, very few large studies have directly compared the two patient populations. This study is the first, large, national study to compare the two groups and will provide an understanding of differences and similarities between in-hospital and out-of-hospital cardiac arrest patients in Denmark. This is important in identifying factors that could possibly increase survival. Furthermore, the results could possibly influence future guideline developments, as trials conducted in the out-of-hospital setting are often extrapolated to the in-hospital setting.


Lars W. Andersen, M.D., M.P.H., Ph.D., D.M.Sc.

Asger Granfeldt, M.D., Ph.D., D.M.Sc.

Mathias J. Holmberg, M.D., M.P.H., Ph.D.

Nikola Stankovic, M.D.