Mortality trends and the impact of exposure on Australian coastal drowning deaths, 2004–2021

Abstract

Objective: The aim of this study is to characterise Australian coastal drowning trends and evaluate impact of exposure on drowning risk. Methods: Descriptive epidemiological analysis of unintentional fatal drowning occurring July 2004-June 2021 at Australian coastal sites (beaches, rock platforms, bays, harbours, offshore locations etc.). Total population, exposed-person and exposed-person-time rates per 100,000 population were calculated by age, sex, socio-economic status, remoteness category and pre-submersion activity. Annual trends were assessed using joinpoint regression. Exposure-based rates used estimates from Surf Life Saving Australia’s National Coastal Safety Survey. Results: The cumulative unintentional coastal fatal drowning rate was 0.43 per 100,000 Australian residents (95%CI: 0.41–0.45) and did not change throughout the study period (p=0.289). The exposed-person rate was 0.67 per 100,000 coastal visitors (95%CI: 0.62–0.72), and there were 0.55 coastal drowning deaths per 10 million coastal visitor hours (95%CI: 0.51–0.59). Men, older people and residents of lower socioeconomic and remote areas had higher drowning rates; rock fishing and scuba diving had the highest activity exposure-based rates. Conclusions: Education- and policy-based coastal safety interventions should focus on identified risk factors to reduce annual coastal drowning rates. Implications for Public Health: Exposure-based risk measurements are important for developing and prioritising interventions; assessments based on counts or total population measures alone may misinform prevention efforts.