TOPLINE:

Traumatic brain injuries (TBIs), especially moderate-to-severe or repeated injuries, were associated with an increased risk for all-cause mortality, with an even stronger link to dementia-related deaths, in new research that spanned more than 70 years. Additionally, falls were the leading cause of TBIs.

METHODOLOGY:

• Researchers assessed data from two cohorts of the Framingham Heart Study. The original cohort included more than 5200 participants (mean age, 44 years; 55% women; mean follow-up, 35 years) with enrollment beginning in 1948, and the offspring cohort included more than 5100 participants (mean age, 36 years; 51.5% women; mean follow-up, 39 years) with enrollment beginning in 1971. Participants were followed from enrollment through death or August 15, 2022.
• TBIs were identified through systematic medical record reviews and validated self-report questionnaires, with events adjudicated using standardized procedures, and were classified as mild, moderate, or severe.
• Participants with incident TBI were matched in a 1:3 ratio to those without TBI by birth year, sex, and cohort.
• Primary outcomes were all-cause, dementia-related, and non-dementia-related mortality.

TAKEAWAY:

• Overall, 17% of the original cohort and 24% of the offspring cohort experienced at least one TBI. Lifetime incidence was 7.0 and 9.1 events per 1000 person-years, respectively, with falls being the leading cause of TBIs in 65% of the original cohort and 83% of the offspring cohort. Women experienced TBIs 27% more frequently than men.
• TBI was associated with an increased risk for all-cause mortality (hazard ratio [HR], 1.15; 95% CI, 1.1-1.3) compared to not having a TBI. The risk was also significantly linked to moderate-to-severe TBI (HR, 1.8) but not with mild TBI.
• TBI was associated with an increased risk for dementia-related mortality in a dose-dependent pattern (mild TBI: HR, 1.6; moderate-to-severe TBI: HR, 3.7) but not with non-dementia-related mortality.
• Experiencing multiple TBIs was linked to all-cause mortality (HR, 2.0) and dementia-related mortality (HR, 3.6) compared to experiencing only one TBI.

IN PRACTICE:

“These findings provide added support for TBI to be considered a chronic condition, and they suggest that preventing falls to reduce TBI could have important implications for dementia and mortality,” the investigators wrote.

SOURCE:

The study was led by Rebecca Burton, Boston University Chobanian & Avedisian School of Medicine, Boston. It was published online on January 30 in JAMA Network Open.

LIMITATIONS:

The study population consisted mainly of well-educated, self-reported non-Hispanic White participants, which limited generalizability. Participants tended to be healthier than nonparticipants, potentially resulting in an underestimation of TBI incidence and mortality risk. The long span of data collection introduced variations in TBI documentation due to evolving awareness and surveillance practices; the self-report questionnaire had limited scope, changed over time, and was not administered at every visit. Additionally, potential misattribution occurred in some cases of dementia-related deaths, and several potential confounders could not be included due to substantial missing data.

DISCLOSURES:

The study was supported by the National Heart, Lung, and Blood Institute; the National Institute on Aging; and the United States Department of Defense. Several investigators reported having financial ties with various sources, with full details provided in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.