Objective: To compare the effectiveness of child safety seats and lap-shoulder belts in rear passenger vehicle seats for 2- to 3-year-old crash survivors.
Design: Cohort study.
Setting: The January 1, 1998, to December 31, 2004, US data on a nationally representative sample of crashes that resulted in at least 1 vehicle being towed away.
Participants: Toddlers who were sitting in rear vehicle seats and using lap-shoulder belts or child seats when involved in highway crashes.
Intervention: Child safety seat vs safety belt.
Outcome measure: Presence of any injury after a crash.
Results: The adjusted odds of injury were 81.8% lower (95% confidence interval, 58.3%-92.1% lower) for toddlers in child seats than belted toddlers.
Conclusions: Child safety seats seem to be more effective rear seat restraints than lap-shoulder safety belts for children aged 2 to 3 years. Laws requiring that children younger than 4 years travel in child safety seats have a sound basis and should remain in force.