Adults who suffered a head injury during a 30-year study period had a death rate twice that of those who did not have a head injury, and the death rate was nearly three times higher in those with moderate or severe head injuries, according to new research from the Perelman School of Medicine from the University of Pennsylvania, published today in JAMA Neurology.
In the United States, over 23 million adults age 40 and older report head injuries resulting in loss of consciousness. Head injuries can be attributed to a number of causes, from car accidents, unintentional falls, or sports injuries. In addition, head injuries have been linked to a number of long-term health problems, including disability, late-onset epilepsy, dementia and stroke.
Studies have previously shown increased short-term mortality associated with head injuries, primarily in hospitalized patients. This longitudinal study analyzed 30 years of data from over 13,000 participants in shared accommodation (those not hospitalized or living in nursing homes) to determine whether head injuries have a long-term impact on adult mortality rates. The researchers found that 18.4 percent of the participants reported one or more head injuries during the study period, and of those who sustained a head injury, 12.4 percent were classified as moderate or severe. The median time between head injury and death was 4.7 years.
Death from all causes was recorded in 64.6 percent of those with head injuries and 54.6 percent of those without head injuries. Adjusting for participant characteristics, the researchers found that the all-cause mortality rate in participants with a head injury was 2.21 times the mortality rate in participants without a head injury. In addition, the death rate in those with more severe head injuries was 2.87 times the death rate in those without a head injury.
Our data show that head injuries are associated with increased mortality rates over the long term. This is especially true for people with multiple or severe head injuries. This underscores the importance of safety measures, such as wearing helmets and seat belts, to avoid head injuries.”
Holly Elser, MD, PhD, MPH, a neurologist in Penn, lead author of the study
The investigators also evaluated the data for specific causes of death in all participants. Overall, the leading causes of death were cancer, cardiovascular disease and neurological disorders (including dementia, epilepsy and stroke). Deaths from neurological disorders and accidental injuries or trauma (such as falls) were more common among those with head injuries.
When the researchers evaluated specific neurological causes of death in participants with head injuries, they found that nearly two-thirds of neurological causes of death were due to neurodegenerative diseases such as Alzheimer’s and Parkinson’s. These diseases accounted for a larger proportion of the total deaths among those with a head injury (14.2 percent) than among those without a head injury (6.6 percent).
“The study data do not explain why the cause of death in individuals with head injuries is more likely to be from neurodegenerative diseases, underscoring the need for further research on the association between these diseases, head injuries and death,” said Andrea LC Schneider, MD, PhD, assistant professor of neurology the Penn.
Study data are from the Atherosclerosis Risk in Communities (ARIC) Study, an ongoing community-based study of 15,792 participants aged 45-65 years living in the suburbs of Minneapolis, Minnesota, Washington County, Maryland, Forsyth County, North Carolina, , and Jackson, Mississippi in 1987–1989.
University of Pennsylvania School of Medicine
Elser, H. et al. (2023) Head injuries and long-term mortality risk in community-dwelling adults. JAMA Neurology. doi.org/10.1001/jamaneurol.2022.5024.