title: Risk and mortality of traumatic brain injury in stroke patients: two nationwide cohort studies.
abstract: OBJECTIVE
  Patients with stroke had higher incidence of falls and hip fractures. However, the risk of traumatic brain injury (TBI) and post-TBI mortality in patients with stroke was not well defined. Our study is to investigate the risk of TBI and post-TBI mortality in patients with stroke.
  
  
  METHODS
  Using reimbursement claims from Taiwan's National Health Insurance Research Database, we conducted a retrospective cohort study of 7622 patients with stroke and 30 488 participants without stroke aged 20 years and older as reference group. Data were collected on newly developed TBI after stroke with 5 to 8 years' follow-up during 2000 to 2008. Another nested cohort study including 7034 hospitalized patients with TBI was also conducted to analyze the contribution of stroke to post-TBI in-hospital mortality.
  
  
  RESULTS
  Compared with the nonstroke cohort, the adjusted hazard ratio of TBI risk among patients with stroke was 2.80 (95% confidence interval = 2.58-3.04) during the follow-up period. Patients with stroke had higher mortality after TBI than those without stroke (10.2% vs 3.2%, P < .0001) with an adjusted relative risk (RR) of 1.46 (95% confidence interval = 1.15-1.84). Recurrent stroke (RR = 1.60), hemorrhagic stroke (RR = 1.68), high medical expenditure for stroke (RR = 1.80), epilepsy (RR = 1.79), neurosurgery (RR = 1.94), and hip fracture (RR = 2.11) were all associated with significantly higher post-TBI mortality among patients with stroke.
  
  
  CONCLUSIONS
  Patients with stroke have an increased risk of TBI and in-hospital mortality after TBI. Various characteristics of stroke severity were all associated with higher post-TBI mortality. Special attention is needed to prevent TBI among these populations.
authors.affiliation: Department of Physical Medicine and Rehabilitation, China Medical University Hospital, Taichung, Taiwan (Drs Chou and Meng); School of Medicine, China Medical University, Taichung, Taiwan (Dr Yeh); Department of Neurology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan (Dr Hu); Graduate Institute of Injury Prevention and Control, Taipei Medical University, Taipei, Taiwan (Dr Chiu); Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan (Ms Chou, Drs Chen, and Liao); Health Policy Research Center, Taipei Medical University Hospital, Taipei, Taiwan (Drs Chen and Liao); School of Medicine, Taipei Medical University, Taipei, Taiwan (Drs Hu, Chen, and Liao).
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Chou
authors.forename: Chun-Chieh
authors.initials: CC
authors.lastname: Yeh
authors.forename: Chaur-Jong
authors.initials: CJ
authors.lastname: Hu
authors.forename: Nai-Hsin
authors.initials: NH
authors.lastname: Meng
authors.forename: Wen-Ta
authors.initials: WT
authors.lastname: Chiu
authors.forename: Wan-Hsin
authors.initials: WH
authors.lastname: Chou
authors.forename: Ta-Liang
authors.initials: TL
authors.lastname: Chen
authors.forename: Chien-Chang
authors.initials: CC
authors.lastname: Liao
mesh_terms: D000328:Adult; D000368:Aged; D001930:Brain Injuries / Q000453:epidemiology* / Q000401:mortality; D015897:Comorbidity; D016001:Confidence Intervals; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology*; D055815:Young Adult