Age-sex-specific risk and burden of fall injury incidence associated with ambient temperature in China: A case-crossover study with 4.19 million cases

Fall injury poses considerable disease burden. However, limited studies investigated the age-sex-specific risk and burden of fall injury associated with ambient temperature. A time-stratified case-crossover study with 4.19 million fall injury cases from the National Injury Surveillance System was conducted in China. We identified a U-shaped relationship between temperature and fall injury in the total population, with higher risk from heat than cold. There were significant age-sex-specific disparities in temperature-related fall injury risk, with diminished heat effects and increased cold effects as age rises, particularly among females. Ambient temperature exhibited a substantial burden on fall injuries, with much higher burden associated with heat than with cold across almost all age groups. Compared to the 2020s, our projections indicate a 1.22-fold increase in heat-related attributable fraction (AF) and a 0.38-fold decrease in cold-related AF under the SSP5-8.5 scenario. These findings can guide injury prevention and control strategies in the context of climate change.