Seatbelt Non-Use and Car Crash Injury: An Interview Study

Objectives:To examine the relationship between seatbelt non-use at the time of a crash, habitual non-use of seatbelts, and car crash injury; and to calculate the population attributable risk for car crash injury due to seatbelt non-use.

Methods:A population-based case control, interview study in Auckland, New Zealand, with 571 injured or killed drivers as cases and 588 population-based controls randomly selected from the driving population.

Results:Unbelted drivers had 10 times the risk of involvement in an injury crash compared to belted drivers after adjustment for multiple confounders. Habitual non-users were likely to be unbelted when involved in a crash. The population attributable risk for seatbelt non-use was 13%.

Conclusions: Non-use of seatbelts is very strongly associated with increased injury crash involvement. Even where seatbelt use rates are higher than 90%, there remains a small group of habitual non-users who are at high risk; these drivers may benefit from targeted interventions.

Keywords:

• Traffic Injury
• Seatbelts
• Case Control Study

ACKNOWLEDGMENTS

The Auckland Car Crash Injury Study was funded by the Health Research Council of New Zealand.

Notes

^A Proportions of controls are adjusted for the clustered sampling design.

^BAdjusted for age, sex, ethnicity, education, driving exposure (hours per week), passenger carriage, time of day, sleepiness score, year of car, blood alcohol concentration, and speed at the time of the crash.

^CAdjusted the same confounders plus wearing seatbelt at the time of the crash.