Effectiveness of Rear Seat Safety Belt Use

Purpose: To estimate the rear seat safety belt effectiveness in reducing traffic fatalities.

Methods: We applied matched cohort design to select passenger vehicles from the Fatality Analysis Reporting System between the crash years 2000 and 2004 in which there was at least one rear seat passenger aged 16 or over in the vehicle, and the driver and/or at least one rear seat passenger aged 16 or over died from the crash. Conditional Poisson regression was used to estimate the adjusted relative risk (aRR) of a fatality for belted rear seat passengers compared to the unbelted. The safety belt effectiveness was then calculated as one minus the aRR.

Results: A total of 26,349 rear seat passengers and drivers in passenger vehicles involved in fatal crashes nationwide from 2000 through 2004 were selected. The rear seat safety belt effectiveness in reducing fatalities was estimated at 61% (95% confidence interval (CI) 55-66%), 71% (95% CI 57-80%), and 56% (95% CI 50-62%) for left, center, and right rear seat in passenger cars, respectively. For light trucks, vans and utility vehicles, the safety belt effectiveness was 71% (95% CI 64-76%), 66% (95% CI 51-76%), and 78% (95% CI 73-83%) for left, center, and right rear seat, respectively. Rear seat safety belts were more effective when the vehicle rolled over or when the passenger was younger than 65-years-old.

Conclusions: This study provides up-to-date estimates of the rear seat safety belt effectiveness and demonstrates the importance of promoting safety belt use among rear seat adult passengers.