RESUMEN
INTRODUCTION: In 2018, the American Academy of Pediatrics updated their car safety seat (CSS) guidelines to recommend that children ride rear-facing as long as possible, yet evidence from observational studies on rear-facing CSS effectiveness is limited. This study estimated the association between rear-facing CSS use and injuries among children aged 0-4 years who were involved in motor vehicle crashes (MVCs). METHODS: This study analysed data on all MVCs involving children aged 0-4 years reported to the Kansas Department of Transportation from 2011 to 2020. Children who were in a rear-facing CSS were compared with children who rode in a forward-facing device. Logistic regression was used to adjust for potential confounders. RESULTS: In unadjusted models, rear-facing CSS use was associated with a 14% reduction in the odds of suffering any injury versus riding in a forward-facing CSS (OR 0.860, 95% CI 0.805 to 0.919). In models adjusted for potential confounders, rear-facing CSS use was associated with a 9% reduction in the odds of any injury relative to riding forward-facing (OR 0.909, 95% CI 0.840 to 0.983). These estimates were driven by children seated in the back outboard positions. Rear-facing CSS use was also negatively associated with incapacitating/fatal injuries, but these estimates were imprecise. CONCLUSIONS: Children aged 0-4 years are less likely to be injured in an MVC if they are restrained in a rear-as opposed to forward-facing CSS. These results are particularly relevant because a number of state CSS laws do not require children of any age to ride rear-facing.