Effects of upgraded child restraint law designed to increase booster seat use in New York.

Objective: The goal was to examine the association between the New York State (NYS) upgraded child restraint law (UCRL) implemented in 2005 and the traffic injury rate among 4- to 6-year-old children in New York State.

Methods: A before/after comparison study of population-based, traffic injury rates for 4- to 6-year-old children, using 0- to 3-year-old children as a comparison group, was performed. The effects of UCRL on injury rates among 0- to 3-year-old and 4- to 6-year-old motor vehicle passengers were estimated by using monthly injury count data from the NYS Department of Motor Vehicles Accident Information System.

Results: Children 4 to 6 years of age experienced an 18% reduction in traffic injury rate (adjusted rate ratio [aRR]: 0.82 [95% confidence interval [CI]: 0.79-0.85]) after UCRL implementation, whereas the injury rate for children 0 to 3 years of age, who were not directly affected by the UCRL, did not change appreciably (aRR: 0.95 [95% CI: 0.90-0.99]). In Poisson regression analysis, the aRR for injury for 4- to 6-year-old children was 1.06 (95% CI: 0.92-1.22]) with adjustment for monthly child restraint use rates, which reveals that the significant reduction in the injury rate among 4- to 6-year-old children was mainly attributable to the 72% increase in the child restraint use rate after UCRL implementation (from 29% before UCRL implementation to 50% after implementation).

Conclusions: This is the first study comparing traffic injury rates for booster seat-aged children before and after implementation of the booster seat law in a single state.