When a spouse has a traumatic brain injury, the uninjured partner's death risk is 24% higher — long-term US cohort

A traumatic brain injury (TBI) may affect not only the injured person but also their spouse, suggests a cohort study published in JAMA Network Open on 3 November 2026.

The study

• Type: observational cohort study using the US Atherosclerosis Risk in Communities (ARIC) study.
• Participants: 3,281 married pairs (6,562 people) enrolled in 1987–1989 and followed through 31 December 2022, a median of 19.5 years.
• Researchers examined whether a TBI in one spouse was associated with death, dementia or major adverse cardiovascular events in the uninjured partner.

Results

• A spouse’s TBI was associated with a 24% higher risk of death in the uninjured partner (adjusted hazard ratio 1.24; 95% CI 1.07–1.43).
• Risks of dementia (HR 1.17; 95% CI 0.88–1.56) and major cardiovascular events (HR 1.15; 95% CI 0.84–1.57) were somewhat higher but not statistically significant.

Why it may matter

The findings point to possible health effects on family members, for example through caregiving burden, though this study does not establish the mechanism.

Limitations

This is an observational study and cannot prove cause and effect; residual confounding is possible. TBI ascertainment was incomplete, especially for mild injuries, and the timing of dementia onset may be imprecise. Unmarried cohabiting partners were excluded, and results may not generalise to same-sex couples.