New Delhi: Drivers who are involved in a vehicle crash are more likely to die if they are obese, says a new US study.
In a severe motor vehicle crash, a moderately obese driver faces a 21 per cent increased risk of death, while it is 56 per cent more risky for the morbidly obese.
Interestingly, underweight and normal weight drivers were found to be at higher risk of dying from a severe crash than slightly overweight drivers.
"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," said Dietrich Jehle, professor of emergency medicine at University at Buffalo, School of Medicine and lead author of the study.
"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," he added.
"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," he said.
Jehle and colleagues investigated the relationship between driver body size and risk of crash-related fatality by analyzing data in the national Fatality Analysis Reporting System database (FARS).
Drivers were grouped based on body mass index (BMI) - weight in kg divided by height in meters squared - into underweight, normal, overweight, slightly obese, moderately obese and morbidly obese categories.
Severe crashes between 2000 and 2005 that involved one or two vehicles (cars, pickups, SUVs or vans) were used in the analysis.
Fatalities considered related to the crash that occurred within 30 days of the crash, such as those resulting from surgery, also were included.
In addition to the overall results, data analyzed by sex show that in the moderately and morbidly obese categories, both male and female drivers independently demonstrated a statistically significant increase in death when compared with normal-weight drivers.
"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," says Jehle.
The study is posted online ahead of print in the American Journal of Emergency Medicine.