An obese person has a considerably higher risk of dying in a severe automobile accident compared to somebody who is not obese, researchers from Buffalo School of Medicine and Biomedical Sciences and at Erie County Medical Center, revealed in the American Journal of Emergency Medicine. Obese people already have a significantly higher risk of developing hypertension (high blood pressure), diabetes, heart disease, stroke, cancer, sleep apnea, and gallbladder disease – mortality risk in severe traffic accidents is now added to the list.

A severely obese driver has a 56% higher chance of dying from a severe accident, compared to somebody of normal weight; the risk for a moderately obese driver is 21% higher.

Dietrich Jehle, MD, and team were surprised to find that drivers who are either of normal weight or underweight have higher mortality rates from severe crashes compared to those who are slightly overweight.

Dr. Jehle said:

    “The severity and patterns of crash injuries depend on a complex interaction of biomechanical factors, including deceleration velocity at impact, seat belt and air bag use, vehicle type and weight, and type of impact. But the effect of body mass on crash outcome has not been previously evaluated in databases of adequate size or controlled for some of these confounding factors.

    Crash test dummies have saved lives and provided invaluable data on how human bodies react to crashes, but they are designed to represent normal-weight individuals. If they represented our overweight American society, there could be further improvements in vehicle design that could decrease mortality.”

Several changes which take into account the fact that a considerable number of people today are obese could save many lives, the authors explained.

Jehle added:

    “Extending the range of adjustable seats would be helpful, as well as encouraging moderately and morbidly obese individuals to buy larger vehicles with more space between the seat and the steering column.

    We also recommend that manufacturers design and test vehicle interiors with obese dummies, which currently are not available, in addition to testing with the 50 percentile (BMI 24.3) male dummy,” he adds. “It would improve safety for the one-third of the U.S. population that is obese. For underweight and normal weight individuals, placing airbags within the seat belt also might be protective.”

In this study, the investigators gathered and analyzed data from the national Fatality Analysis Reporting System Database (FARS). Their aim was to find out what the relationship between driver body-size and death risk in severe traffic accidents might be.

For a crash to be included in FARS, it must include “a vehicle traveling on a roadway customarily open to the public and must result in the death of an occupant of a vehicle or a non-motorist.”

155,584 out of a total of 168,049 drivers in severe traffic accidents met the criteria for the researchers’ analysis.

The drivers were divided into six categories, according to their BMI (body mass index):

  • underweight
  • normal weight
  • overweight
  • slightly obese
  • moderately obese
  • morbidly obese

For the analysis, they used data on cars, SUVs (Vans) and Pickups that had been involved in severe crashes between 2000 and 2005. They also included deaths that occurred within 30 days of the traffic accident, including those occurring during/after surgery.

Morbidly and moderately obese male and female drivers were found to have a statistically higher risk of death compared to drivers of normal weight, the researchers found.

Jehle said:

    “The rate of obesity is continuing to rise, so is it imperative that car designs are modified to protect the obese population, and that crash tests are done using a full range of dummy sizes.”

“Influence of obesity on mortality of drivers in severe motor vehicle crashes”
Dietrich Jehle, MD, Seth Gemme, Christopher Jehle
American Journal of Emergency Medicine doi:10.1016/j.ajem.2010.10.017

Written by Christian Nordqvist