New research suggests that insomnia is a major contributor to deaths caused by motor vehicle crashes and other unintentional fatal injuries.

Researchers found that that the risk of unintentional fatal injury increased in a dose-dependent manner with the number of insomnia symptoms present. People with all three symptoms of insomnia were 2.8 times more likely to die from a fatal injury than those with no insomnia symptoms, even after adjusting for potential confounders such as alcohol consumption and daily use of sleep medication.

According to the Centers for Disease Control and Prevention, there are more than 126,000 unintentional injury deaths in the U.S. each year, making it the fifth leading cause of death. There are more than 33,000 motor vehicle traffic fatalities and more than 27,000 unintentional fall deaths annually, as well as 29.3 million emergency department visits related to unintentional injuries.

"Our results suggest that a large proportion of unintentional fatal injuries and fatal motor vehicle injuries could have been prevented in the absence of insomnia," Lars Laugsand, lead author of the study, said in a statement. "Increasing public health awareness about insomnia and identifying and treating people with insomnia may be important in preventing unintentional fatal injuries."

For the study, researchers analyzed data from a population-based survey data of more than 54,000 men and women between 20 and 89 years of age. Cause of death was identified using a national registry. During the 13-year follow-up period there were 277 unintentional fatal injuries, including 169 deaths from falls and 57 deaths from motor vehicle crashes.

Among the three insomnia symptoms, difficulty falling asleep appeared to have the strongest and most robust association with fatal injuries. People who almost always had difficulty falling asleep were more than two times more likely to die from a motor vehicle injury (hazard ratio = 2.40) and more than 1.5 times more likely to die from any fatal injury (HR = 1.66) than people who never had trouble initiating sleep. Further analysis found that self-reported difficulty falling asleep contributed to 34 percent of motor vehicle deaths and eight percent of all unintentional fatal injuries, which could have been prevented in the absence of insomnia.

"Healthy sleep is essential for physical health, mental well-being, and personal and public safety," said American Academy of Sleep Medicine President Dr. Timothy Morgenthaler, a national spokesperson for the Healthy Sleep Project. "Sleep is a necessity, not a luxury, and the promotion of healthy sleep should be a fundamental public health priority."

The results underscore the importance of the "Sleep Well, Be Well" campaign of the National Healthy Sleep Awareness Project. The campaign aims to increase awareness of the importance of sleep as one of the three pillars of a healthy lifestyle

The findings are detailed in the November issue of the journal Sleep.