Booster seats in motor vehicles are designed to raise the seated position of children 4–8 years old several inches above the vehicle seat to position the vehicle’s lap and shoulder belt correctly on the child. Public health and traffic safety agencies recommend the use of booster seats in motor vehicles for children until the vehicle’s lap and shoulder belt can fit them properly—typically when they have reached a height of 57 inches, have a sitting height of 29 inches, and weigh about 80 pounds. Using booster seats has been estimated to reduce the odds of sustaining clinically significant injuries in a crash by 59 percent for children aged 4–7, compared with using ordinary vehicle seat belts (Durbin et al. 2003). Despite this evidence of effectiveness, many children in the United States do not ride in age-appropriate booster seats. For example, Decina and Lococo (2004) observed child restraint use in six states and found that although virtually all infants and 90 percent of children aged 1–3 were restrained in child safety seats, only 37.2 percent of children aged 4–8 were in child safety seats or booster seats; the remainder used either the vehicle seat belt alone or no restraint at all. Given the strong evidence on the safety benefits of booster seats, various interventions have been implemented to increase their use. However, the evidence on the effectiveness of such interventions has not been as clear as the evidence that the booster seats do what they are intended to do, which is to reduce the likelihood or severity of injuries in the event of a crash. To examine the effectiveness of booster seat promotion interventions, we undertook a systematic review of studies, using the Cochrane systematic review method to perform a meta-analysis. We began with a search of the Cochrane Injuries Group Specialized Register, the Cochrane Central Register of Controlled Trials, EMBASE, LILACS, MEDLINE, the Combined Health Information Database, the National Research Register, the Science Citation Index, the Science and Social Science Citation Index, transport research databases, and reference lists of relevant articles. We also contacted experts in the field. The Cochrane protocol called for including randomized and controlled before-and-after trials. Two reviewers (J.E. and H.E.) independently assessed the quality of the studies and extracted data from eligible studies. Final decisions on whether a study would be included were reached by consensus among all authors. The included studies were categorized and analyzed by type of intervention; outcomes for each specific intervention type were compared with outcomes with no intervention; then outcomes for all five intervention types were aggregated and compared with the aggregated outcomes for no intervention. Five studies involving a total of 3,070 individuals met the criteria for inclusion in the meta-analysis. All interventions for promoting the use of booster seats for 4–8-year-olds demonstrated a positive effect (relative risk [RR]=1.43; 95% CI=1.05–1.96). Providing incentives in combination with education demonstrated a beneficial effect (RR=1.32; 95% CI=1.12–1.55; n=1,898). Distribution of free booster seats in combination with education also had a beneficial effect (RR=2.34; 95% CI=1.50–3.63; n=380), and so did education-only interventions (RR=1.32; 95% CI=1.16–1.49; n=563). In one study, the effect of enforcement of a booster seat law was evaluated; although enforcement showed a positive effect, the association was not statistically significant. Available evidence suggests that several types of interventions to increase the use of booster seats for children aged 4–8 are effective. Combining incentives (in the form of discount coupons or gift certificates for booster seats) or distribution of free booster seats in combination with education increased the acquisition and use of booster seats, as did education alone. The effect of enforcing booster seat laws remains unclear. The single study in our meta-analysis that looked at enforcement found that it did not significantly increase booster seat use. There is some evidence that legislation has a beneficial effect on the acquisition and use of booster seats, but it is mainly from uncontrolled before-and-after studies, which did not meet the criteria for inclusion in the meta-analysis. (Author/publisher)
Samenvatting