OBJECTIVE: Traffic crashes are multi-factorial events caused by human factors, technical issues and environmental conditions. The present study was aimed to determine the role of human factors in traffic crashes in Iran using the proportional odds regression model.
METHODS: The database of all traffic crashes in Iran in 2010 (n = 592168) registered through the "COM.114" police forms was investigated. Human risk factors leading to traffic crashes were determined and the odds ratio of each risk factor was estimated using an ordinal regression model and adjusted for potential confounding factors such as age, gender and lighting status within and outside of cities.
RESULTS: The drivers' mean age ± standard deviation were 34.1 ± 14.0 years. The most prevalent risk factors leading to death within cities were "Disregarding traffic rules and regulations" (45%), "driver rush" (31%) and "alcohol consumption" (12.3%). Using the proportional odds regression model, alcohol consumption was the most significant human risk factor in traffic crashes within cities (OR: 6.5, 95% CI: 4.88-8.65) and out of cities (OR: 1.73, 95% CI: 1.22-3.29).
CONCLUSIONS: The public health strategies and preventive policies should be focused on more common human risk factors such as disregarding traffic rules and regulations, driver rush and alcohol consumption due to their greater population attributable fraction and more intuitive impacts on society.