This thesis includes six papers that are related to the incidence and outcome from cardiac arrest in the United Kingdom. The Utstein-style template for reporting in-hospital cardiac arrest defines the data elements of the epidemiology and outcome of cardiac arrest that should be collected so that valid comparisons can be made between emergency medical services (EMS) systems, countries, and regions. Much of this reporting template concerns the documentation of data relating to the post-resuscitation care phase of patient management and links well the papers in this thesis that describe the characteristics and outcome of patients admitted to intensive care units (ICUs) after cardiac arrest. The first report from the UK National Cardiac Arrest Audit (NCAA) documented the incidence and outcome from in-hospital cardiac arrest in 144 acute hospitals in 2011-2013. Although the incidence overall was 1.6 cardiac arrests per 1000 hospital admissions, there was considerable seasonal variation. The rate of survival to hospital discharge was 18.4 %. Analysis of the Intensive Care National Audit and Research Centre (ICNARC) case mix programme database (CMPD) provides valuable insights into the increasing numbers of patients admitted to ICUs comatose after resuscitation from cardiac arrest. During the period 1995-2005, mechanically ventilated post-cardiac arrest patients accounted for 5.8% of all ICU admissions; 42.9% survived to leave ICU and 28.6% survived to hospital discharge. A later analysis of the ICNARC CMPD showed that cardiac arrest survivors represented a steadily increasing proportion of mechanically ventilated admissions during 2004 to 2014. Their hospital mortality decreased during the study period. A third analysis of the ICNARC CMPD showed a significant change in temperature management strategy (indicated by a change in the lowest body temperature in the first 24 h of admission) following publication of the Targeted Temperature Management Trial (TTM) trial in December 2013; this change was not associated with a change in the mortality rate. The final paper in this thesis, a secondary analysis of the PARAMEDIC-2 study showed that the treatment effect of adrenaline on return of spontaneous circulation (ROSC) at hospital admission was the same when given by the intravenous (IV) and intraosseous (IO) routes.