OBJECTIVE: To quantify the independent contribution of recently enacted booster seat laws on appropriate restraint use by child passengers in motor vehicles. DESIGN: Longitudinal study of children involved in crashes with data collected via insurance claims records and a validated telephone survey. SETTING: Sixteen states and Washington, DC, from December 1, 1998, through December 31, 2004. PARTICIPANTS: Probability sample of 5198 vehicles in crashes involving 6102 children aged 4 to 7 years, representing 78 159 vehicles and 91 752 children. MAIN EXPOSURES: Booster seat law provisions, child age, state, and secular trends. MAIN OUTCOME MEASURE: Reported appropriate restraint use for this age group, including forward-facing child safety seats, belt-positioning booster seats, and combination seats. RESULTS: Children aged 4 to 7 years in states with booster seat laws were 39% more likely to be reported as appropriately restrained than were children in other states (prevalence ratio [PR], 1.39; 95% confidence interval [CI], 1.14-1.70). Children aged 4 to 5 years were 23% more likely (PR,1.23; 95% CI, 0.80-1.42) and children 6 to 7 years twice as likely (PR, 2.09; 95% CI, 1.46-2.99) to be reported as appropriately restrained. For children aged 6 to 7 years, when compared with no law, laws through age 7 years were most effective (PR, 3.71; 95% CI, 2.49-5.42), followed by laws through age 4 or 5 years (PR, 1.43; 95% CI, 0.89-2.24). CONCLUSION: Given the higher current use of age-appropriate restraints among children 4 to 5 years compared with older children, future upgrades to child restraint laws should include children through at least age 7 years to maximize the number of children properly restrained for their age.
OBJECTIVE: To quantify the independent contribution of recently enacted booster seat laws on appropriate restraint use by child passengers in motor vehicles. DESIGN: Longitudinal study of children involved in crashes with data collected via insurance claims records and a validated telephone survey. SETTING: Sixteen states and Washington, DC, from December 1, 1998, through December 31, 2004. PARTICIPANTS: Probability sample of 5198 vehicles in crashes involving 6102 children aged 4 to 7 years, representing 78 159 vehicles and 91 752 children. MAIN EXPOSURES: Booster seat law provisions, child age, state, and secular trends. MAIN OUTCOME MEASURE: Reported appropriate restraint use for this age group, including forward-facing child safety seats, belt-positioning booster seats, and combination seats. RESULTS:Children aged 4 to 7 years in states with booster seat laws were 39% more likely to be reported as appropriately restrained than were children in other states (prevalence ratio [PR], 1.39; 95% confidence interval [CI], 1.14-1.70). Children aged 4 to 5 years were 23% more likely (PR,1.23; 95% CI, 0.80-1.42) and children 6 to 7 years twice as likely (PR, 2.09; 95% CI, 1.46-2.99) to be reported as appropriately restrained. For children aged 6 to 7 years, when compared with no law, laws through age 7 years were most effective (PR, 3.71; 95% CI, 2.49-5.42), followed by laws through age 4 or 5 years (PR, 1.43; 95% CI, 0.89-2.24). CONCLUSION: Given the higher current use of age-appropriate restraints among children 4 to 5 years compared with older children, future upgrades to child restraint laws should include children through at least age 7 years to maximize the number of children properly restrained for their age.