Impact of high temperature on road injury mortality in a changing climate, 1990-2019: A global analysis

Previous studies have shown that extreme heat likely increases the risk of road injuries. However, the global burden of road injuries due to high temperature and contributing factors remain unclear. This study aims to characterize the global, regional and national burden of road injuries due to high temperature from 1990 to 2019.

Based on the Global Burden of Disease (GBD) study 2019, we obtained the numbers and age-standardized mortality rates (ASMR) and age-standardized disability-adjusted life years (DALY) rates (ASDR) of the road injury due to high temperature at global, regional, and national levels from 1990 to 2019. The world is divided into five climate zones according to the average annual temperature of each country: tropical, subtropical, warm temperate, cold temperate, and boreal. We used the generalized additive models (GAM) to model the trends of road injuries globally and by region.

Globally, between 1990 and 2019, the deaths of road injury attributable to high temperature increased significantly from 20,270 (95% uncertainty interval [UI], 7836 to 42,716) to 28,396 (95% UI, 13,311 to 51,178), and the DALYs increased from 1,169,309 (95% UI, 450,834 to 2,491,075) to 1,414,527 (95% UI, 658,347 to 2,543,613). But the ASMR and the ASDR slightly decreased by 8.49% and 13.16%, respectively. The burden of road injury death attributable to high temperature remained high in low SDI and tropical regions. In addition, road transport infrastructure investment per inhabitant is associated with the burden of road injuries attributable to high temperature.

Globally, the ASMR and ASDR for road injuries attributable to high temperature decreased from 1990 to 2019, but the absolute death and DALYs continued to increase. Thus, concerning global warming, implementation of prevention and interventions to reduce road injuries from heat exposure should be stressed globally.