Cardiac arrest as a reportable condition: a cohort study of the first 6 years of the Norwegian out-of-hospital cardiac arrest registry.

Objectives: The Norwegian Cardiac Arrest Registry (NorCAR) was established in 2013 when cardiac arrest became a mandatory reportable condition. The aim of this cohort study is to describe how the world's first mandatory, population-based cardiac arrest registry evolved during its first 6 years.

Setting: Norway has a total population of 5.