Effects of Child Age and Body Size on Serious Injury From Passenger Air-Bag Presence in Motor Vehicle Crashes

Abstract

Background. Current recommendations regarding children traveling in passenger vehicles equipped with passenger air bags are based, in part, on evidence that the air-bag–related risk of injury and death is higher for children ≤12 years of age. However, the age or body size required to allow a child to be seated safely in front of a passenger air bag is unknown. Objective. To evaluate specific cutoff points for age, height, and weight as effect modifiers of the association between the presence of a passenger air bag and serious injury among children involved in motor vehicle crashes (MVCs), while controlling for important crash factors. Design. A national population-based cohort of children involved in MVCs and included in the National Automotive Sampling System (NASS) Crashworthiness Data System (CDS) database from 1995 to 2002 was studied. NASS CDS clusters, strata, and weights were included in all analyses. Subjects. Children 0 to 18 years of age involved in MVCs and seated in the right front passenger seat. Main Outcome Measure. Serious injury, defined as an Abbreviated Injury Scale score of ≥3 for any body region. Results. A total of 3790 patients (1 month to 18 years of age) were represented in the NASS CDS database during the 8-year period. Sixty children (1.6%) were seriously injured (Abbreviated Injury Scale score of ≥3). Among age, height, and weight, age of 0 to 14 years (versus 15–18 years) was the only consistent effect modifier of the association between air-bag presence (or air-bag deployment) and serious injury, particularly for crashes with a moderate probability of injury. In analyses stratified according to age and adjusted for important crash factors, children 0 to 14 years of age involved in frontal collisions seemed to be at increased risk of serious injury from air-bag presence (odds ratio [OR]: 2.66; 95% confidence interval [CI]: 0.23–30.9) and deployment (OR: 6.13; 95% CI: 0.30–126), although these values did not reach statistical significance. Among children 15 to 18 years of age involved in frontal collisions, there was a protective effect on injury from both air-bag presence (OR: 0.19; 95% CI: 0.05–0.75) and deployment (OR: 0.31; 95% CI: 0.09–0.99). These findings persisted in analyses involving all collision types. We did not identify similar cutoff points for height or weight. Conclusions. Children up to 14 years of age may be at risk for serious preventable injury when seated in front of a passenger air bag, and children 15 to 18 years of age seem to experience protective effects of air-bag presence and deployment. Age may be a better marker than height or weight for risk assessment regarding children and air bags.