The Danish Drowning Cohort: Evaluation of Data Availability for Fatal and Non-Fatal Drowning Incidents

The Danish Drowning Cohort has collected nationwide prehospital data on fatal and non-fatal drowning incidents in Denmark. The database contains 47 variables: 22 variables from the existing Utstein Drowning Template and 25 additional variables based on the availability in the Danish prehospital medical records. This study aimed to estimate the availability of data (ie, data completeness) for the predefined prehospital registry variables in the Danish Drowning Cohort and the availability of Utstein variables in the subpopulations of drowning patients with and without out-of-hospital cardiac arrest (OHCA).

This study included all fatal and non-fatal drownings in the Danish Drowning Cohort from January 1, 2016, to December 31, 2023. Data availability rates were reported for all variables in the Danish Drowning Cohort and the Utstein variables in the subpopulations of patients with and without OHCA, presented as medians with interquartile ranges (IQR).

A total of 1,664 drowning patients were analysed (697, 42% with OHCA). The median data availability rate in the Danish Drowning Cohort was 100% (IQR: 88-100%): 100% (IQR: 81-100%) for non-OHCA and 100% (IQR: 87-100%) for OHCA patients. Among the subset of 22 available Utstein variables, the overall data availability was 95% (IQR: 75-100%). For the 17 Utstein variables applicable to both non-OHCA and OHCA, the availability rate was 92% (IQR 76-100%) in non-OHCA cases and 88% (IQR 78-100%) in OHCA cases, with no difference between groups. Overall, 21 of 79 (26%) Utstein variables were unavailable in the Danish setting.

The Danish Drowning Cohort contained nationwide data on fatal and non-fatal drowning patients with high degrees of availability. Data availability was high for most variables defined in the Utstein Drowning Template, both for drowning patients with and without OHCA. However, 21 of 79 Utstein variables were unavailable despite the Danish high-resource healthcare setting.