Belt-positioning booster seats and reduction in risk of injury among children in vehicle crashes

Abstract

Durbin DR, Elliott MR, Winston FK (Children's Hospital of Pennsylvania, Philadelphia, PA) More than 12 states have ratified laws that require booster seats for children older than 4 years of age. Most states have restraint laws that address children through age 4 years. The lack of booster seat effectiveness data may be why stronger child restraint laws have not been passed. The relative effectiveness of belt-positioning booster seats versus seat belts alone in decreasing the risk of injury to children aged 4 to 7 years was examined in a cross-sectional investigation. Children aged 4 to 7 years involved in crashes of insured vehicles in 15 states were evaluated. The data were obtained from insurance claims records and a telephone survey. A probability sample of 3,616 crashes involving 4,243 children, weighted to represent 56,593 children in 48,257 crashes, was obtained between December 1, 1998, and May 31, 2002. Analyses were performed to compute the relative risk of injury for children aged 4 to 7 years who were restrained in belt-positioned booster seats versus seat belts. The primary outcome measure was parent report of clinically significant injuries. Restraint use varied by age. Seat belts were used in 42% of 4-year-olds, 72% of 5-year-olds, and 89% of 6- and 7-year-olds. The belt-positioning booster seats were used in 16% of 4-year-olds, 13% of 5-year-olds, and 4% of 6- and 7-year-olds. Injuries occurred in 1.18% of 4- to 7-year-olds, including 1.95% of those in seat belts and 0.77% of those in belt-positioning booster seats. There were 5 deaths among children in seat belts and none in children in belt-positioning booster seats. The odds of injury, adjusted for child, driver, crash, and vehicle characteristics, were 59% lower for children aged 4 to 7 years who were in belt-positioning booster seats versus those in seat belts (odds ratio 0.41; 95% confidence interval 0.20 to 0.86). Children in belt-positioning booster seats had no injuries to the abdomen, neck/spine/back, or lower extremities. Children in seat belts had injuries to all body regions. Children in seat belts were more likely to be in vehicles driven by young drivers and more likely to be situated in the front seat. Children in belt-positioning booster seats were more likely to be positioned in the rear seats. Belt-positioning booster seats were linked to added safety benefits compared with seat belts for children aged 4 to 7 years, including a decrease in injuries classically linked to improper seat belt fit for children.