Distance traveled and motor vehicle injury risk: Findings from a cohort study

To investigate the association between exposure to road traffic and being hospitalized or needing a sick leave because of motor vehicle injuries. Data from the cohort study SUN (Seguimiento Universidad de Navarra) were used. Every two years, participants are inquired regarding the incidence of motor vehicle injuries requiring either hospitalization equal or longer to 24 hrs or sick leave from work for equal or longer than 24 hrs. They are also inquired regarding the distance travelled over a year. Data were available for 9897 participants who had no history of motor vehicle injuries prior to enrolment in the cohort. 481 and 31 of them reported a motor vehicle-related incident sick leave or hospitalization in the last 2 years. Multivariate logistic regression analysis controlling for age and gender indicated a statistically significant effect of travelling more in the likelihood of sustaining a motor vehicle injuries (whether leading to hospital or sick leave). Using those who travel fewer than 1000 km per year as the reference, those travelling between 1000 and 10000 present an OR of 1.53 (95%CI 1.01-2.33) and increased amounts of travel have higher ORs with the highest being among those travelling 50000 or more (OR 3.06 ,95%CI 1.69-5.54). The reduction of travel in private means of transportation is hardly ever expressed as a means to reduce motor vehicle injuries. Our findings confirm at the individual level the importance of travel and stress the importance of adequately controlling for it when evaluating other factors, such as gender.