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.