title: Long-term disability and survival in traumatic brain injury: results from the National Institute on Disability and Rehabilitation Research Model Systems.
abstract: OBJECTIVE
  To document long-term survival in 1-year survivors of traumatic brain injury (TBI); to compare the use of the Disability Rating Scale (DRS) and FIM as factors in the estimation of survival probabilities; and to investigate the effect of time since injury and secular trends in mortality.
  
  
  METHODS
  Cohort study of 1-year survivors of TBI followed up to 20 years postinjury. Statistical methods include standardized mortality ratio, Kaplan-Meier survival curve, proportional hazards regression, and person-year logistic regression.
  
  
  METHODS
  Postdischarge from rehabilitation units.
  
  
  METHODS
  Population-based sample of persons (N=7228) who were admitted to a TBI Model Systems facility and survived at least 1 year postinjury. These persons contributed 32,505 person-years, with 537 deaths, over the 1989 to 2011 study period.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Survival.
  
  
  RESULTS
  Survival was poorer than that of the general population (standardized mortality ratio=2.1; 95% confidence interval, 1.9-2.3). Age, sex, and functional disability were significant risk factors for mortality (P<.001). FIM- and DRS-based proportional hazards survival models had comparable predictive performance (C index: .80 vs .80; Akaike information criterion: 11,005 vs 11,015). Time since injury and current calendar year were not significant predictors of long-term survival (both P>.05).
  
  
  CONCLUSIONS
  Long-term survival prognosis in TBI depends on age, sex, and disability. FIM and DRS are useful prognostic measures with comparable statistical performance. Age- and disability-specific mortality rates in TBI have not declined over the last 20 years. A survival prognosis calculator is available online (http://www.LifeExpectancy.org/tbims.shtml).
authors.affiliation: Life Expectancy Project, San Francisco, CA. Electronic address: Brooks@LifeExpectancy.org.
authors.forename: Jordan C
authors.initials: JC
authors.lastname: Brooks
authors.forename: David J
authors.initials: DJ
authors.lastname: Strauss
authors.forename: Robert M
authors.initials: RM
authors.lastname: Shavelle
authors.forename: David R
authors.initials: DR
authors.lastname: Paculdo
authors.forename: Flora M
authors.initials: FM
authors.lastname: Hammond
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Harrison-Felix
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000401:mortality* / Q000534:rehabilitation*; D006233:Persons with Disabilities / Q000534:rehabilitation; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D055815:Young Adult
keywords: AIC; Akaike information criterion; Brain injuries; CI; DRS; Disability Rating Scale; Mortality; Rehabilitation; SMR; SSDI; Social Security Death Index; Survival; TBI; confidence interval; standardized mortality ratio; traumatic brain injury