The association between meteorological variables and road traffic injuries: a study from Macao

Objective. Correlation analysis and multiple linear regression analysis were conducted to estimate the influence of meteorological factors on road traffic injuries stratified by severity. Crash rate was defined as mean monthly road traffic accidents per 1,000 vectors. Design. Ecological time-series study. Setting. Macao traffic accident registry database between January 1st, 2001 and November 31st, 2016. Participants. In total, 393,176 traffic accidents and 72,501 cases of road traffic injuries (RTIs) were enrolled; patients' severity was divided into mild injury, required hospitalisation, and death. Exposure. Variation of monthly meteorological factors. Main outcome measure. Weather-condition-related road traffic accidents, injuries, and deaths. Results. Windy weather significantly correlated with increased number of traffic accidents among all transport vectors (r = .375 to .637; p < 0.001). Multiple linear regression showed temperature (B = 0.704; p < 0.05) and humidity (B = -0.537; p < 0.001) were independent factors for mild injury. The role of windy weather was relatively more obvious among patients with severe injuries (B = 0.304; p < 0.001) or those who died (B = 0.015; p < 0.001). A longer duration of sunshine was also associated to RTI-related deaths (B = 0.015; p < 0.001). In total, 13.4% of RTIs were attributable to meteorological factors and may be preventable. Conclusion. The World Health Organization stated that RTIs are a major but neglected public health challenge. This study demonstrates meteorological factors have significant effects on any degree of RTIs. The results may not be generalized to other climates or populations while the findings may have implications in both preventing injuries and to announce safety precautions regarding trauma and motor vehicle collisions to the general public by public agencies.