Results of new data analysis show that children in belt-positioning booster seats were 45 percent less likely to sustain injuries in a crash than were children using only standard vehicle seat belts.
Researchers did not detect an appreciable difference in risk of injury between the use of high-back and backless booster seats.
Data covering automobile accidents involving children from a nine-year period in 15 states and Washington, D.C., was collected from insurance claim records concerning crashes with at least one child passenger 15 or younger.
Interviews were conducted with parents or drivers involved in 21,943 crashes in which at least one child (for a total of 34,732 children) received medical attention. Interviews were also conducted for crashes in which a child occupant was not injured.
Children in side-impact crashes benefited most when booster seats were used: risk of injury was reduced 68 percent for near-side impacts, and 82% for far-side impacts.
Head injuries accounted for approximately 65 percent of all injuries, regardless of the type of restraint used. Injured children in booster seats most commonly received face and lower extremity injuries (9 percent and 8 percent, respectively), with a notable absence of abdominal injuries.
Among children using seat beats, abdominal injuries were the second most common, with a greater percentage of injuries to the abdomen compared to the face (12 percent and 9 percent, respectively).
While the study sample represents any level of crash reported to an insurance company (from fender benders to fatal accidents), the majority of injuries studied were almost exclusively nonfatal.
The study's authors link the passage of booster seat laws (which vary in age limits from state to state) with a nearly 40 percent increase in the use of such seats in children up to age 7.
The authors conclude that pediatricians should continue to recommend the use of belt-positioning booster seats for children until they are at least 8 years old or 4'9".
The study, from the Children's Hospital of Philadelphia and the University of Pennsylvania, Philadelphia's Center for Clinical Epidemiology and Biostatistics, was published today in the journal Pediatrics.
In a related story, CBS News correspondent Sandra Gibbons reports that nearly 9,000 babies visit emergency rooms each years due to the improper use of infant car seats - not inside cars but outside of them, such as placing car seats on counters, tables, beds and sofas.
The American Academy of Pediatrics says most of the injuries are to the head, but some children also suffered fractured arms or legs.
Experts say car seats should always be placed on a hard, flat floor where there is no danger they will topple over.
For more info:
Car Safety Seats: A Guide for Families (American Academy of Pediatrics)