Booster seat laws and fatalities in children 4 to 7 years of age.

OBJECTIVE To determine whether state booster seat laws were associated with decreased fatality rates in children 4 to 7 years of age in the United States. METHODS Retrospective, longitudinal analysis of all motor vehicle occupant crashes involving children 4 to 7 years of age identified in the Fatality Analysis Reporting System from January 1999 through December 2009. The main outcome measure was fatality rates of motor vehicle occupants aged 4 to 7 years. Because most booster laws exclude children 6 to 7 years of age, we performed separate analyses for children 4 to 5, 6, and 7 years of age. RESULTS When controlling for other motor vehicle legislation, temporal and economic factors, states with booster seat laws had a lower risk of fatalities in 4- to 5-year-olds than states without booster seat laws (adjusted incidence rate ratio 0.89; 95% confidence interval [CI] 0.81-0.99). States with booster seat laws that included 6-year-olds had an adjusted incidence rate ratio of 0.77 (95% CI 0.65-0.91) for motor vehicle collision fatalities of 6-year-olds and those that included 7-year-olds had an adjusted incidence rate ratio of 0.75 (95% CI, 0.62-0.91) for motor vehicle collision fatalities of 7-year-olds. CONCLUSIONS Booster seat laws are associated with decreased fatalities in children 4 to 7 years of age, with the strongest association seen in children 6 to 7 years of age. Future legislative efforts should extend current laws to children aged 6 to 7 years.