Research Reports - Long-term disability and survival in traumatic brain injury
Arch Phys Med Rehabil. 2013 Jul 16
Brooks JC, Strauss DJ, Shavelle RM, Paculdo DR, Hammond FM, Harrison-Felix CL
OBJECTIVE: To document long-term survival in one-year survivors of traumatic
brain injury (TBI); to compare the use of the Disability Rating Scale (DRS) and
Functional Independence Measure (FIM) as factors in the estimation of survival
probabilities; and to investigate the effect of time since injury and secular
trends in mortality.
DESIGN: Cohort study of one-year survivors of TBI; followed up to 20 years
post-injury. Statistical methods include standardized mortality ratios (SMRs),
Kaplan-Meier survival curve, proportional hazard regression, and "person-year"
SETTING: Post-discharge from National Institute on Disability and Rehabilitation
Research-funded TBI Model Systems rehabilitation units.
PARTICIPANTS: Population-based sample of 7,228 persons who were admitted to a TBI
Model Systems facility and survived at least 1 year post-injury. These persons
contributed 32,505 person-years, with 537 deaths, over the 1989 to 2011 study
INTERVENTIONS: Not Applicable.
MAIN OUTCOME MEASURES: Survival.
RESULTS: Survival was poorer than that of the general population (SMR=2.1; 95% CI
1.9-2.3). Age, sex, and functional disability were significant risk factors for
mortality (p < 0.0001). FIM- and DRS-based proportional hazard survival models
had comparable predictive performance (C-index 0.80 vs. 0.80, AIC 11,005 vs
11,015). Time since injury and current calendar year were not significant
predictors of long-term survival (both p > 0.05).
CONCLUSION: 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