State booster seat laws save lives of 4- to 7-year olds

Investigators evaluated the effectiveness of booster seat laws in reducing motor vehicle fatalities in children aged from 4 to 7 years. According to the Fatality Analysis Reporting System, 3,639 children in this age group were killed in motor vehicle accidents from 1999 to 2009.

At the start of this study period, no state had enacted laws regarding booster seat use for children 4 years and older; by the end of the period, 47 states and the District of Columbia had. Investigators compared fatality rates before and after such legislation was implemented in individual states and rates in states with and without booster seat legislation.

Because most booster seat laws do not apply to 6- and 7-year-olds, investigators analyzed data for 6-, 7-, and 4- to 5-year-olds separately. They also analyzed their findings to account for other legislative and economic factors associated with motor vehicle fatalities, such as state highway speed limit, maximum legal blood alcohol limit, adult fatality rates, median household income, and-to account for temporal trends-the year in which each accident occurred.

The unadjusted “before” and “after” fatality rates in states that enacted booster seat legislation during the study period decreased after enactment for children in the 4- to 5-year-old and 6-year-old age groups but not in 7-year-olds. By contrast, states with no booster seat legislation showed no significant changes in fatality rates for any age group during the study period.

After controlling for confounding factors, states with booster seat laws had decreased motor vehicle crash fatality rates in all age groups compared with states with no laws. Legislation had the strongest protective effect in children aged from 6 to 7 years (Mannix R,  et al. Pediatrics. 2012;130[6]:996-1002).

Commentary

This study serves 2 purposes: First, it is a reminder of the usefulness of the work you do every day educating families about automobile safety, specifically use of booster seats in 4- to 7-year-olds. And second, this is a call to know your state law in this matter. If you practice in 1 of the 3 states with no booster seat requirements, advocate for them. If your current law excludes 6- and 7-year-olds, use the evidence described in this study to push for legislative change. -Michael Burke, MD