Not all child safety seats are created equal: the potential dangers of shield booster seats

Children are safest when traveling in a child safety seat appropriate for their age and size. Previous research indicates that children are often transitioned to shield booster seats (SBSs) before reaching the 40-lb weight limit for their forward-facing child safety seat (FFCSS). These children could have otherwise been restrained in a FFCSS as is currently recommended by the American Academy of Pediatrics and the National Highway Traffic Safety Administration. The objective of this study was to compare the injury patterns among children who were restrained in SBSs and FFCSSs. Children in FFCSSs were chosen as a comparison group because SBS are predominantly used to restrain children who are <40 lb and could have been restrained in an FFCSS, and SBSs are no longer certified for use in children who are >40 lb.

This is a cohort study involving restrained crash victims who were admitted to a level 1 pediatric trauma center between 1991 and 2003. Patients were older than 1 year, weighed between 20 and 40 lb, and were restrained in an SBS (N = 16) or an FFCSS (N = 30). Injury Severity Score, Abbreviated Injury Scale, Glasgow coma score, intensive care admission, length of stay, and acute care charges served as outcomes of interest.

No significant differences regarding crash and occupant characteristics were found (mean Delta V, crash type, passenger compartment intrusion, driver restraint use). Odds of severe injury were greater for children in SBSs compared with children in FFCSSs as measured by Injury Severity Score >15 (odds ratio [OR]: 8.3; 95% confidence interval [CI]: 2.1-33.6), intensive care admission (OR: 5.5; 95% CI: 1.5-20.5), length of stay >2 days (OR: 6.3; 95% CI: 1.6-24.6), and Abbreviated Injury Scale > or = 3 (OR: 4.4; 95% CI: 1.2-16.1). Furthermore, SBS cases had greater odds of head (OR: 4.5; 95% CI: 1.2-17.3), chest (OR: 29.0; 95% CI: 3.1-267.3), and abdominal/pelvic injury (25% vs 0%).

This study provides information about the increased risk of injury associated with shield boosters when compared with FFCSSs. The challenge for pediatricians is not only to promote the use of child restraints but also to ensure that parents use the most appropriate restraint for their child's age and weight.