237855 Seatbelt Effectiveness in Preventing Injury for Obese Drivers

Tuesday, November 1, 2011: 9:30 AM

Keshia Pollack, PhD, MPH , Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD
Jason Forman, PhD , European Center for Injury Prevention, University of Navarra, Pamplona, Spain
Rafael Heredero-Ordoyo , European Center for Injury Prevention, University of Navarra, Pamplona, Spain
Eduardo Del Pozo De Dios , European Center for Injury Prevention, University of Navarra, Pamplona, Spain
Richard Kent, PhD , Center for Applied Biomechanics, University of Virginia, Charlottesville, VA
Maria Segui-Gomez, MD, ScD, MPH , European Center for Injury Prevention, University of Navarra, Pamplona, Spain
Background: Seatbelt ineffectiveness has been hypothesized as a mechanism for the increased risk of injury for obese versus nonobese drivers. The purpose of this study is to understand seatbelt protection among obese drivers, and determine if the estimated benefits of seatbelts differ by body mass index (BMI). These results will illuminate important issues regarding the potential limitations of currently available safety technology as applied to an increasing segment of the U.S. population.

Methods: This case control study used data on adult drivers involved in frontal collisions between 1999 and 2008 from the National Automotive Sampling System-Crashworthiness Data System to determine if the effectiveness of seatbelts varied by BMI. Multivariate Poisson regression was used to determine the risk factors that influenced moderate to severe injury (maximum Abbreviated Injury Score, mAIS, 2 and greater (2+)), overall and by body region, by BMI.

Results: Of the 16,473 drivers analyzed, 21.7% (n=3,066) were obese. Obese drivers were significantly less likely than other drivers to be belted (p <0.001) and more likely to sustain mAIS2+ injury overall and to all body regions except the head, even when belted (p <0.001). As crash severity increased, obese drivers had the fastest rate of decline of seatbelt effectiveness, which for a severe crash was nearly 30% lower than for a nonobese driver. Similar findings, although of lesser magnitude were seen for overweight drivers.

Conclusions: These results suggest a need to ensure all drivers wear seatbelts and that seatbelts effectively mitigate injury-producing forces for drivers of all body sizes.

Learning Areas:
Public health or related research

Learning Objectives:
1. Discuss the importance of exploring obesity as a risk factor for motor vehicle crash injuries. 2. Explain why seatbelts are hypothesized to provide less protection to obese drivers than nonobese drivers. 3. Analyze data from a national crash surveillance system to determine if seatbelts offer equal protection from injury for obese versus nonobese drivers.

Keywords: Motor Vehicles, Obesity

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I was the the PI on this study and responsible for the methodology, analysis and reporting.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.