By Megan Brooks
NEW YORK (Reuters Health) - Using a booster seat instead of just a seat belt significantly reduces the risk of injury in children aged 4 to 8 years old who are involved in a car crash, according to an updated assessment of booster seat effectiveness released today.
Moreover, the results indicate that in this age group, booster seats without a back are just as protective as those with a back.
Car seat belts are built for average-size adults, not children. When a child outgrows a harness-type car seat, it's recommended that he or she graduate to a booster seat, usually around age 4 and weight 40 pounds.
Booster seats work by raising the child up so that the vehicle's lap-shoulder belt is properly positioned across his chest and hips -- to distribute crash forces across the sturdiest parts of a child's body.
"Previous research demonstrating the benefits of booster seats over seat belts for children is outdated," Dr. Kristy B. Arbogast from the Center for Injury Research and Prevention at Children's Hospital of Philadelphia in Pennsylvania and colleagues note in the journal Pediatrics.
To revisit the issue, they analyzed data on 7151 children aged 4 to 8 who were involved in a total of 6591 car crashes. All of the children were in the back seat and most -- 70 percent, or 5547 children -- were restrained in a regular seat belt. Only 30 percent -- or 1604 children -- were strapped into a booster seat.
Arbogast's team found that children in booster seats had approximately half the injury risk as children in seat belts (0.67 vs. 1.36 percent).
"This study reaffirms the current recommendations for booster seat use for children through age 8," Arbogast told Reuters Health. "This study includes a greater percentage of 6, 7 and 8 year olds than previously studied (in 2003)," she added.
When considering all crash directions and vehicle model years, children who used booster seats were 45 percent less likely to suffer injuries than children who were using the vehicle seat belt.
"Booster seats were shown to be particularly effective in side impact crashes, which are the most deadly and injury-causing crashes for children," Arbogast said.
Booster seat use was associated with a 68 percent reduction in risk of injury for near-side impacts and an 82 percent reduction in risk of injury for far-side impacts.
"Importantly," the researchers note in their report, the results suggest that the effectiveness of booster seats does not vary by the type of booster seat: backless or high-back.
Most kids prefer backless booster seats because they look less like a "baby" car seat, the researchers note. The current results, they say, "give confidence to parents and health educators that choosing this type of restraint for their child does not represent a compromise in safety."
Based on these updated data, booster seats represent "best practice," the researchers conclude, and should be used once a child outgrows a harness-type car seat and until he or she is at least 8 years old.
"These data provide timely confirmation that current efforts to upgrade states' child passenger safety laws to include booster seat use are well-founded," Arbogast added.
SOURCE: Pediatrics, November 2009.