Effectiveness of child restraint legislation to reduce motor vehicle related serious injuries and fatalities: A national interrupted time series analysis

Children that are unrestrained while travelling in a motor vehicle are more vulnerable to serious injury and death. The greatest levels of crash protection are achieved when children use the most age or size appropriate form of restraint. In this study, we aimed to examine the effectiveness of the introduction of age-appropriate child restraint legislation on serious and fatal injury in five Australian states and territories. For this interrupted time series analysis, we used a segmented regression method to assess the association between the implementation of child-restraint legislation and motor-vehicle related serious injuries and fatalities using data obtained from transport authorities in each jurisdiction. We estimated the change in annual rates after the implementation of legislation with the number of motor-vehicle accidents resulting in fatalities or serious injuries as the outcome, and the total number of injuries (minor, serious and fatal) as an offset in the model. We identified 10882 motor-vehicle related crashes resulting in fatalities (n = 188), serious injuries (n = 1730) and minor injuries (n = 8964). In NSW and VIC, the rate ratio was statistically significant and positive, indicating an increase in the rate of serious injuries and fatalities in the period post-legislation compared to the period prior to legislation. In all other states and territories, we did not find a statistically significant effect of legislation Road safety programs incorporating interventions targeted at increasing awareness of optimal restraint practices, strengthened enforcement and measures to improve the affordability of restraints are needed to support legislation.