Cochrane review: Interventions for promoting booster seat use in four to eight year olds traveling in motor vehicles

Background Public health and traffic safety agencies recommend use of booster seats in motor vehicles for children aged four to eight years, and various interventions have been implemented to increase their use by individuals who transport children in motor vehicles. There is little evidence regarding the effectiveness of these interventions, hence the need to examine what works and what does not. Objectives To assess the effectiveness of interventions intended to increase acquisition and use of booster seats in motor vehicles among four to eight year olds. Search strategy We searched the Cochrane Injuries Group's Specialized Register, the Cochrane Central Register of Controlled Trials, MEDLINE (January 1966 to April 2005), EMBASE (1980 to April 2005), LILACS, Transport Research Databases (1988 to April 2005), Australian Transport Index (1976 to April 2005), additional databases and reference lists of relevant articles. We also contacted experts in the field. Selection criteria We included randomized and controlled before-and-after trials that investigated the effects of interventions to promote booster seat use. Data collection and analysis Two authors independently assessed trial quality and extracted data. Study authors were contacted for additional information. Main results Five studies involving 3,070 individuals met the criteria for inclusion in the meta-analysis. All interventions for promoting use of booster seats among 4 to 8 year olds demonstrated a positive effect (relative risk (RR) 1.43; 95% confidence intervals (CI) 1.05 to 1.96). Incentives combined with education demonstrated a beneficial effect (RR 1.32, 95% CI 1.12 to 1.55; n = 1,898). Distribution of free booster seats combined with education also had a beneficial effect (RR 2.34; 95% CI 1.50 to 3.63; n = 380) as did education-only interventions (RR 1.32; 95% CI 1.16 to 1.49; n = 563). One study which evaluated enforcement of booster seat law met the criteria for inclusion in the meta-analysis, but demonstrated no marked beneficial effect. Authors' conclusions Available evidence suggests that interventions to increase use of booster seats among children age four to eight years are effective. Combining incentives (booster seat discount coupons or gift certificates) or distribution of free booster seats with education demonstrated marked beneficial outcomes for acquisition and use of booster seats for four to eight year olds. There is some evidence of beneficial effect of legislation on acquisition and use of booster seats but this was mainly from uncontrolled before-and-after studies, which did not meet the criteria for inclusion in the meta-analysis. Plain language summary Interventions for promoting the use of booster seats in four to eight year olds traveling in motor vehicles: how effective are they? Booster seats are designed for use by children aged four to eight years, while traveling in motor vehicles. They aim to raise the child off the vehicle seat so that the adult seat belt fits correctly and the child can travel in greater comfort and safety. Public health and traffic safety agencies recommend the use of booster seats in children until the vehicle seatbelt fits properly; typically when the child is at least 58 inches tall, has a sitting height of 29 inches and weighs about 80 pounds. In children aged four to seven years, booster seats are estimated to reduce the odds of sustaining clinically significant injuries during a crash by 59%, when compared to using ordinary vehicle seatbelts. Despite the evidence of effectiveness, many children are not restrained in age-appropriate booster seats. In light of the strong evidence for the safety benefits of booster seats, interventions specifically aimed at promoting their use have been implemented. To evaluate the effectiveness of such interventions, the authors of this systematic review examined all high quality trials investigating their effect on acquisition and use of booster seats. The authors found five studies involving a total of 3,070 participants. All interventions investigated by the studies were found to increase the use of booster seats, compared to the group receiving no intervention. The distribution of free booster seats combined with education on their use, had a marked beneficial effect, as did incentives (for example, booster seat discount coupons or gift certificates) combined with education. Education-only interventions also produced beneficial outcomes. One of the studies evaluated the effectiveness of the enforcement of a booster seat law, but did not detect an effect on usage. The authors concluded that the current evidence suggests that several types of interventions aimed at increasing the use of booster seats among children aged four to eight years, are effective. However, there is still a need for further high quality trials, especially those conducted outside of the USA and Australia, where current research dominates.