Drowning in Denmark: A Registry-based Study of Fatal and Non-fatal Drowning From 2016 to 2023

Prehospital Center, Region Zealand1,664 enrolled

Overview

Using nationwide data from the prehospital electronic health records from 2016 to 2023, this registry-based cohort study aims to establish a nationwide epidemiological profile of non-fatal and fatal drowning patients in Denmark in adherence with the Utstein Style For Drowning (USFD) recommended guidelines for uniform reporting of data from drowning. This includes reporting the annual incidence rates per 100,000 person-years, assessing the associations between predefined prognostic variables and 30-day survival, and reporting the spatial distribution of drowning incidents presented on a map of Denmark.

Purpose The purpose of this study is to establish a nationwide epidemiological profile of non-fatal and fatal drowning patients in Denmark which can be used to target educational, preventative, rescue, or treatment strategies to reduce the number of fatal and non-fatal drowning incidents in Denmark. Objectives The primary objective is to estimate the yearly incidence rates of drowning patients in Denmark treated by the Danish Emergency Medical Services from 2016 to 2023. The secondary objective is to report the associations between predefined prognostic variables and 30-day survival. Study design A nationwide registry-based study with data from the Danish Drowning Cohort (extracted from the prehospital electronic health records using syndromic surveillance and extensive manual validation) from 2016 to 2023 with 30-day follow-up.

Study Type

OBSERVATIONAL

Enrollment

1,664

Conditions

Drowning

Interventions

Eligibility

Sex: ALL

Medical Language ↔ Plain English

Inclusion criteria: * The patient must have been experiencing respiratory impairment from submersion or immersion in liquid AND * The patient must have been in contact with the Danish prehospital emergency medical services. Exclusion criteria: \- Patients were excluded if the incident involved submersion or immersion with aspiration, but the patient did not experience respiratory impairment. For example, if the patient was rescued from the water without signs of respiratory impairment, or if the respondent reported "a few coughs" or "voluntary cough".

Outcomes

Primary Outcomes

Annual drowning incidence rates per 100,000 person-years from 2016-2023

The primary objective is to estimate the annual incidence of fatal and non-fatal drowning patients in Denmark treated by the prehospital emergency medical services from 2016 to 2023 and will be reported as the annual number of cases per 100,000 person-years.

Time frame: Counts of fatal and non-fatal drowning incidents will be obtained between 2016-2023.

30-day survival following drowning incidents in Denmark from 2016-2023

The primary outcome is 30-day survival (alive/dead).

Time frame: 30-day follow-up after the drowning incident

Secondary Outcomes

Association between prognostic variables and 30-day survival

This outcome will explore predefined prognostic variables associated with 30-day survival after a drowning incident. The following risk factors will be analysed using multivariable logistic regression models and presented as odds ratios (ORs) with 95% confidence intervals (CIs): witnessed status, sex, age, OHCA, submersion duration, season, location.

Time frame: From 2016-2023

Map of fatal and non-fatal drowning incidents in Denmark from 2016-2023

Showing a map of geographical localization of drowning in Denmark in the study period indicating 30-day mortality and survival