Research Reports - Long-term survival following traumatic brain injury
Neuroepidemiology. 2016 May 11;47(1):1-10. [Epub ahead of print]
Fuller GW(1), Ransom J, Mandrekar J, Brown AW.
BACKGROUND: Long-term mortality may be increased following traumatic brain injury
(TBI); however, the degree to which survival could be reduced is unknown. We
aimed at modelling life expectancy following post-acute TBI to provide
predictions of longevity and quantify differences in survivorship with the
METHODS: A population-based retrospective cohort study using data from the
Rochester Epidemiology Project (REP) was performed. A random sample of patients
from Olmsted County, Minnesota with a confirmed TBI between 1987 and 2000 was
identified and vital status determined in 2013. Parametric survival modelling was
then used to develop a model to predict life expectancy following TBI conditional
on age at injury. Survivorship following TBI was also compared with the general
population and age- and gender-matched non-head injured REP controls.
RESULTS: Seven hundred and sixty nine patients were included in complete case
analyses. The median follow-up time was 16.1 years (interquartile range 9.0-20.4)
with 120 deaths occurring in the cohort during the study period. Survival after
acute TBI was well represented by a Gompertz distribution. Victims of TBI
surviving for at least 6 months post-injury demonstrated a much higher ongoing
mortality rate compared to the US general population and non-TBI controls (hazard
ratio 1.47, 95% CI 1.15-1.87). US general population cohort life table data was
used to update the Gompertz model's shape and scale parameters to account for
cohort effects and allow prediction of life expectancy in contemporary TBI.
CONCLUSIONS: Survivors of TBI have decreased life expectancy compared to the
general population. This may be secondary to the head injury itself or result
from patient characteristics associated with both the propensity for TBI and
increased early mortality. Post-TBI life expectancy estimates may be useful to
guide prognosis, in public health planning, for actuarial applications and in the
extrapolation of outcomes for TBI economic models.