Survival and mortality following TBI

Evaluation of life expectancy (LE) post traumatic brain injury (TBI) is important for planning services for patients and for dealing with medico-legal aspects. We hypothesized that LE for patients who survived 2 years post injury is equal to that of the general population (GP).

A cohort of 279 patients was assembled during a 5-year period and was followed for 22-27 years. During follow-up, 32 patients (11.5%) died, creating a huge censored data (88.5%). Analyses included standard mortality ratio (SMR), Kaplan-Meier method (KM), Cox proportional hazards regression analysis (PH) and calculations of life expectancy.

About 77% of the patients were under 35 years of age at injury. This age cut-off point yielded differences for survival longevity by χ² tests (p < 0.0001), by KM analysis (p < 0.0001) and by Cox PH regression analysis (p < 0.0001, HR = 13.95). SMR for the entire cohort was 1.86. Shortening of LE in comparison with the GP is 3.58 years. Estimated shortening of LE by severity for mild, moderate and severe injury were -0.51, 4.11 and 13.77 years, respectively.

Patients with mild TBI have a LE similar to the GP, and a reduction in LE was closely related to moderate and severe brain injury.