Child traffic injuries fell in New York State after a new law required upgraded restraints, researchers reported.
The law was associated with an 18% decrease in the number of traffic injuries among children ages 4 through 6, who were the targets of the new law, according to Kainan Sun, PhD, and colleagues at the New York State Department of Health, in Albany.
The decline was almost entirely attributable to an increase in the use of booster seats after the 2005 passage of the law, Sun and colleagues said online in Pediatrics.
At the same time, there was no effect on the injury rate among children ages 0 through 3, who were not directly affected by the new law, Sun and colleagues reported.
Motor vehicle crashes are the leading cause of death among children ages 4 through 6, the researchers noted, and the National Highway Traffic Safety Administration recommends belt-positioning booster seats when children no longer fit forward-facing child safety seats.
New York’s law requiring booster seats or other restraints for that age group came into effect March 27, 2005, and Sun and colleagues undertook an analysis of its effects on booster seat use and traffic injuries, using before-and-after data.
Among children involved in motor vehicle crashes, about 30% of those ages 4 through 6 were using booster seats in 2003 and 2004, Sun and colleagues found. In contrast, the rate increased to about 50% in the years 2006 and 2007.
The children were also more likely to be seated in the rear after the new law went into effect, which Sun and colleagues argued was probably an effect of the increase in booster seat use, since they are more commonly used in rear seats.
In the younger age group, the rate of use among children in car crashes rose slowly — from 76% in 2003 to 84% in 2007 — but did not show a spike in 2005, they found.
The injury rate for the 4-to-6-year-old children fell over the study period, from 31 injuries per 10,000 population in 2003 to 24 injuries per 10,000 in 2007. The decrease was significant at P<0.0001, the researchers reported. On the other hand, for the 0-to-3-year-old children, the injury rate fell slightly from 2003 to 2004 but remained stable from 2004 to 2007, they found. All told, there were 7,538 traffic injuries among the younger age group and 9,503 among the older children during the study period, Sun and colleagues reported. In a regression analysis, the adjusted population-based injury rate among the older children was 18% less after the new law than before, they found, with an adjusted rate ratio of 0.82 (and a 95% confidence interval from 0.79 to 0.85). The adjusted rate ratio for the younger children was 0.95, with a 95% confidence interval from 0.90 to 0.99. When the researchers recalculated the regression, adjusting for changing booster seat use, the rate ratio for injuries among the older children rose to 1.06 and was no longer significant, they found. That finding "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," they argued. The study implies that the new law increased the use of car restraints among older children and that there was a consequent decrease in the number of traffic injuries in that age group, they concluded. The study was not able to assess proper use of booster seats, but the authors commented that the National Highway Safety Administration has found one or more critical user errors in approximately half of booster seats observed.