Head Trauma with or without Mild Brain Injury Increases the Risk of Future Traumatic Death: A Controlled Prospective 15-Year Follow-Up Study

Patients who have recovered from traumatic brain injury (TBI) show an increased risk of premature death. To investigate long-term mortality rates in a population admitted to the hospital for head injury (HI), we conducted a population-based prospective case-control, record-linkage study, All subjects who were living in Northern Ostrobothnia, and who were admitted to Oulu University Hospital in 1999 because of HI (n=737), and 2196 controls matched by age, gender, and residence randomly drawn from the population of Northern Ostrobothnia were included. Death rate and causes of death in HI subjects during 15 years of follow-up was compared with the general population controls. The crude mortality rates were 56.9, 18.6, and 23.8% for subjects having moderate-to-severe traumatic brain injury (TBI), mild TBI, and head injury without TBI, respectively. The corresponding approximate annual mortality rates were 6.7%, 1.4%, and 1.9%. All types of index HI predicted a significant risk of traumatic death in the future. Subjects who had HI without TBI had an increased risk of both death from all causes (hazard ratio 2.00; 95% confidence interval 1.57-2.55) and intentional or unintentional traumatic death (4.01, 2.20-7.30), compared with controls. The main founding was that even HI without TBI carries an increased risk of future traumatic death. The reason for this remains unknown and further studies are needed. To prevent such premature deaths, post-traumatic therapy should include an interview focusing on lifestyle factors.