Background In Japan, drowning is the second leading cause of deaths due to unintentional injuries following motor vehicle crashes among children. Drowning took the lives of 80 children aged 0–14 in 2014. The purpose of this study is to analyse the trends in drowning death rates and the share of drowning in unintentional injuries among children.

Methods Mortality data on unintentional injuries including drowning provided by the Vital Statistics of Japan was used. The deaths caused by the Great East Japan Earthquake in 2011 were removed from the analysis to avoid confounding.

Results The drowning death rate among all ages was 4.5 per 100,000 population in 1995, and 6.0 in 2014. Among infants under 1 year old, the drowning death rate was 1.9 per 100,000 population in 1995, and 0.2 in 2014. Among 1–4 year olds, the drowning death rate was 3.7 per 100,000 population in 1995, and 0.5 in 2014. Among 5–9 year olds, the drowning death rate was 1.7 per 100,000 population in 1995, and 0.4 in 2014. Among 10–14 year olds, the drowning death rate was 0.7 per 100,000 population in 1995, and 0.6 in 2014.

The share of drowning death in all deaths due to unintentional injuries among all ages was 12.3% in 1995, and 19.2% in 2014. Among infants under 1 year old, the share of drowning death in all deaths due to unintentional injuries was 6.7% in 1995, and 2.6% in 2014. Among 1–4 year olds, the share of drowning death in all deaths due to unintentional injuries was 27.9% in 1995, and 18.6% in 2014. Among 5–9 year olds, the share of drowning death in all deaths due to unintentional injuries was 21.3% in 1995, and 31.4% in 2014. Among 10–14 year olds, the share of drowning death in all deaths due to unintentional injuries was 14.1% in 1995, and 29.4% in 2014.

Conclusions Drowning death rates among children decreased significantly, but the share of drowning death in all deaths due to unintentional injuries virtually did not change. This means that the incidence of drowning was stable and high compared to other unintentional injuries.

To reduce the number of drowning deaths, it is important for not only students but also parents, teachers and doctors to learn about drowning facts and statistics. It is also necessary to improve health education including drowning prevention curriculum in cooperation with various health specialties to create a healthy school environment for students.