Incidence of head injury and traumatic brain injury among people with Alzheimer's disease.

BACKGROUND: Injuries caused by falling are a major health concern among older population. For older people, falls are the leading cause of head injuries; especially, persons with cognitive disorders have an increased risk of falling.

OBJECTIVE: To compare the incidence of head injury and traumatic brain injury (TBI) among persons with Alzheimer's disease (AD) with persons without AD.

METHODS: This register-based study was conducted on a nationwide cohort, which includes all community-dwelling persons diagnosed with AD in Finland in 2005-2011. Persons with previous head injuries were excluded, leaving 67 172 persons with AD. For each person with AD, a matching person without AD and previous head injury were identified with respect to age, sex and university hospital district. The Cox proportional hazard model and competing risk analyses were used to estimate HR for head injury and TBI.

RESULTS: Persons with AD had 1.34-fold (95% CI 1.29 to 1.40) risk of head injuries and 1.49-fold (95% CI 1.40 to 1.59) risk of TBIs after accounting for competing risks of death and full adjustment by socioeconomic status, drug use and comorbidities.

CONCLUSION: Persons with AD are more likely to have a head injury or TBI incident than persons without AD.