Long-term mortality trends in functionally-dependent adults following severe traumatic-brain injury

Primary objective: To investigate mortality trends in functionally dependent adults following traumatic brain injury (TBI). Methods: Data for 966 consecutive admissions to a specialist TBI rehabilitation service were reviewed. Details for 69 subjects who were functionally dependent at rehabilitation discharge were cross-referenced against the State Government Death Register. The observed mortality rate was compared to an equivalent population sample derived from Australian Life Tables. Results: Twenty-five subjects (36%) were deceased at an average 10.5 years post-injury (SD 5 years; range 1.7-18.8 years). The observed numbers of deaths far exceeded the expected population figure (1.9) for the same period (1989-2007) yielding a standardized mortality rate of 13.2. Mortality trends suggested a bimodal distribution, with more deaths in the first 5 years post-injury followed by no further deaths until 9 years post-injury. Conclusions: Mortality in this functionally-dependent group was significantly associated with age, male sex and degree of disability at discharge. The bimodal distribution of mortality data suggests different contributory mechanisms to early vs. late mortality in this group.