Rear-seat Seatbelt Laws and Restraint Use in Rear-seated Teen Passengers Traveling in Passenger Vehicles Involved in a Fatal Collision on a US Roadway

Background: There is widespread belief that after childhood rear-seated motor vehicle occupants do not need to wear-seat seatbelts to travel safely. This belief is reflected in the fact that, in many states, teen passengers can ride legally unbelted in the rear seat of a passenger vehicle.

Methods: The Fatality Analysis Reporting System for 2010-2011 was used to examine factors associated with teen use of rear-seat seatbelts (n = 3,655) and with injury outcomes of belted and unbelted rear-seated teen passengers traveling in a passenger vehicle on a US roadway. Multilevel models controlled for nonindependence of cases using SAS Glimmix. Odds ratio (OR) is reported with 95% confidence interval (CI).

Results: Slightly more than half (50.8%) of rear-seated teens were restrained, but this declined linearly with age from 65.8% of 13- to 14-year-olds to 43.3% of 18- to 19-year-olds. Overall, 77.0% of rear-seat mortality occurred in unbelted teens. Passengers of belted drivers were more frequently belted (64.1% vs. 19.0%, χ = 586.2, p < 0.0001). Nearly one-fifth (18.5%) of rear-seated teens were ejected, with 95.8% of ejections in unrestrained teens. Presence of a rear-seat seatbelt law was associated with higher restraint use (55.9% vs. 40.0%, χ = 89.0, p < 0.0001). However, in adjusted multilevel, multivariable models, belt status varied by whether the seatbelt law was primary (OR, 1.60; 95% CI, 1.29-1.99) or secondary enforcement (OR, 1.33; 95% CI, 0.98-1.78).

Conclusion: Presence of a primary enforced rear-seat seatbelt law was associated with significantly higher belt use. Ejection was associated with higher mortality and being unrestrained. More than three quarters of rear-seated teens who died were unrestrained.

Level Of Evidence: Epidemiologic study, level III.