Premature Mortality and Risk Factors for Drowning in 204 Countries and Territories, 1990~2019: An Age-Period-Cohort Analysis for the Global Burden of Disease 2019 Study

Abstract

Background: Drowning is the world’s third leading unintentional injury killer, and no study has explored the period and cohort effects for premature drowning mortality. A systematic analysis of premature drowning mortality and its related risk factors is needed for the targeted policy making and to promote the progress of Sustainable Development Goals (SDGs).

Methods: Premature mortality is defined as those who die before 70 years of age referring to the definition proposed by WHO. We used mortality and years of life lost (YLLs) data of drowning from Global Burden of Disease (GBD) 2019 to analyze the current situation and trends of total premature drowning mortality. The countries and territories were classified into five groups according to their Socio-demographic Index (SDI). Age-period-cohort (APC) model was used to determine the age, period and cohort effects in different countries and territories. Age effect was defined as the fitted longitudinal age-specific rates in reference cohort adjusted for period deviations, and period (cohort) effect was defined as the rate ratio in specific survey year (birth cohort) compared with reference survey year (birth cohort). We additionally analyzed the premature drowning mortality attributable to three risk factors: alcohol use, high temperature and occupational injuries.

Findings: Globally, there were nearly 202 thousand premature deaths from drowning and 12·4 million YLLs in 2019, with a 54·5% and 62·1% reduction compared with 1990, respectively. Among 204 countries and territories, there were 113 countries and territories with at least 100 premature drowning deaths in 2019, and eight of the top ten countries were in middle and low-middle SDI groups. Middle and low-middle SDI groups had the highest age standardized mortality rate (ASMR) (2·97 and 3·60 per 100000, respectively), the highest number of deaths due to drowning (66 and 61 thousand, respectively), and the highest proportions of drowning among injuries (6·52% and 6·69%, respectively). In middle and low-middle SDI groups, some countries and territories, such as Brazil [net drift: -2·69, (95% confidence intervals [CI]: -2·82, -2·55)], China [net drift: -2·64, (95%CI: -2·87, -2·41)], and India [net drift: -2·11, (95%CI: -2·33, -1·89)] have made great progress in decreasing drowning mortality. However, the burden of premature drowning mortality in those countries and territories were still over three times than that in high SDI group. In the meantime, there were many countries which had high ASMR of premature drowning death have gained less or even showed significant increasing trends during the past three decades such as Thailand, Zimbabwe and Lesotho. Zimbabwe and Lesotho even showed rising trends in almost all periods and almost all cohorts. Occupational injuries and high temperature accounted for more premature drowning deaths in middle and low-middle SDI groups, such as Bangladesh [premature drowning mortality rate was 1·30 (95%CI: 0·74, 2·39) and 0·37 (95%CI: 0·10, 0·79) per 100000 in 2019 for occupational injuries and high temperature, respectively], Thailand [0·89 (95%CI: 0·60, 1·30) and 0·44 (95%CI: 0·10, 0·99) per 100000], Viet Nam [0·57 (95%CI: 0·29, 0·89) and 0·31 (95%CI: 0·09, 0·76) per 100000] and Philippines [0·74 (95%CI: 0·48, 1·11) and 0·27 (95%CI: 0·05, 0·82) per 100000], than in other groups, while alcohol use, although lower than in high SDI group, also caused huge burden in middle and low-middle SDI groups, such as India [1109 (95%CI: 462, 2028) premature drowning deaths in 2019], Thailand [330 (95%CI: 134, 628)], and Viet Nam [338 (95%CI: 91, 685)].

Interpretation: Despite the declining trend of the premature drowning mortality globally, there are still many people dying from drowning, especially for those living in countries and territories of middle and low-middle SDI groups. All triple risk factors (occupational injuries, high temperature, and alcohol use) contributed to the increasing period and cohort effects in middle and low-middle SDI groups. Drowning should be treated as a solvable problem rather than an accident and targeted strategies to reduce the premature drowning mortality should be developed, such as embedding it into the progress of SDGs.

Funding: Supported by National Natural Science Foundation of China (82273654, 82073573).

Declaration of Interests: All the authors declare no competing interests.

Keywords: drowning, premature mortality, risk factors, age-period-cohort analysis