title: Traumatic brain injury and risk of dementia in older veterans.
abstract: OBJECTIVE
  Traumatic brain injury (TBI) is common in military personnel, and there is growing concern about the long-term effects of TBI on the brain; however, few studies have examined the association between TBI and risk of dementia in veterans.
  
  
  METHODS
  We performed a retrospective cohort study of 188,764 US veterans aged 55 years or older who had at least one inpatient or outpatient visit during both the baseline (2000-2003) and follow-up (2003-2012) periods and did not have a dementia diagnosis at baseline. TBI and dementia diagnoses were determined using ICD-9 codes in electronic medical records. Fine-Gray proportional hazards models were used to determine whether TBI was associated with greater risk of incident dementia, accounting for the competing risk of death and adjusting for demographics, medical comorbidities, and psychiatric disorders.
  
  
  RESULTS
  Veterans were a mean age of 68 years at baseline. During the 9-year follow-up period, 16% of those with TBI developed dementia compared with 10% of those without TBI (adjusted hazard ratio, 1.57; 95% confidence interval: 1.35-1.83). There was evidence of an additive association between TBI and other conditions on risk of dementia.
  
  
  CONCLUSIONS
  TBI in older veterans was associated with a 60% increase in the risk of developing dementia over 9 years after accounting for competing risks and potential confounders. Our results suggest that TBI in older veterans may predispose toward development of symptomatic dementia and raise concern about the potential long-term consequences of TBI in younger veterans and civilians.
authors: From the University of California, San Francisco (D.E.B., A.K., K.A.K., A.L.B., K.Y.); San Francisco Veterans Affairs Medical Center (D.E.B., A.K., K.A.K., A.L.B., K.Y.); and Uniformed Services University of the Health Sciences and Center for Neuroscience and Regenerative Medicine (R.D.-A.), Bethesda, MD. Deborah.barnes@ucsf.edu.
authors: Deborah E
authors: DE
authors: Barnes
authors: From the University of California, San Francisco (D.E.B., A.K., K.A.K., A.L.B., K.Y.); San Francisco Veterans Affairs Medical Center (D.E.B., A.K., K.A.K., A.L.B., K.Y.); and Uniformed Services University of the Health Sciences and Center for Neuroscience and Regenerative Medicine (R.D.-A.), Bethesda, MD.
authors: Allison
authors: A
authors: Kaup
authors: From the University of California, San Francisco (D.E.B., A.K., K.A.K., A.L.B., K.Y.); San Francisco Veterans Affairs Medical Center (D.E.B., A.K., K.A.K., A.L.B., K.Y.); and Uniformed Services University of the Health Sciences and Center for Neuroscience and Regenerative Medicine (R.D.-A.), Bethesda, MD.
authors: Katharine A
authors: KA
authors: Kirby
authors: From the University of California, San Francisco (D.E.B., A.K., K.A.K., A.L.B., K.Y.); San Francisco Veterans Affairs Medical Center (D.E.B., A.K., K.A.K., A.L.B., K.Y.); and Uniformed Services University of the Health Sciences and Center for Neuroscience and Regenerative Medicine (R.D.-A.), Bethesda, MD.
authors: Amy L
authors: AL
authors: Byers
authors: From the University of California, San Francisco (D.E.B., A.K., K.A.K., A.L.B., K.Y.); San Francisco Veterans Affairs Medical Center (D.E.B., A.K., K.A.K., A.L.B., K.Y.); and Uniformed Services University of the Health Sciences and Center for Neuroscience and Regenerative Medicine (R.D.-A.), Bethesda, MD.
authors: Ramon
authors: R
authors: Diaz-Arrastia
authors: From the University of California, San Francisco (D.E.B., A.K., K.A.K., A.L.B., K.Y.); San Francisco Veterans Affairs Medical Center (D.E.B., A.K., K.A.K., A.L.B., K.Y.); and Uniformed Services University of the Health Sciences and Center for Neuroscience and Regenerative Medicine (R.D.-A.), Bethesda, MD.
authors: Kristine
authors: K
authors: Yaffe
mesh_terms: D000368:Aged; D001930:Brain Injuries / Q000150:complications / Q000453:epidemiology*; D003704:Dementia / Q000453:epidemiology* / Q000209:etiology; D004198:Disease Susceptibility; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012306:Risk; D014481:United States / Q000453:epidemiology; D014728:Veterans