Abstract
IMPORTANCE: Longer-term mortality in individuals who have survived a traumatic brain injury (TBI) is not known. OBJECTIVES: To examine the relationship between TBI and premature mortality, particularly by external causes, and determine the role of psychiatric comorbidity. DESIGN, SETTING, AND PATIENTS: We studied all persons born in 1954 or later in Sweden who received inpatient and outpatient International Classification of Diseases-based diagnoses of TBI from 1969 to 2009 (n = 218,300). We compared mortality rates 6 months or more after TBI to general population controls matched on age and sex (n = 2,163,190) and to unaffected siblings of patients with TBI (n = 150,513). Furthermore, we specifically examined external causes of death (suicide, injury, or assault). We conducted sensitivity analyses to investigate whether mortality rates differed by sex, age at death, severity (including concussion), and different follow-up times after diagnosis. MAIN OUTCOMES AND MEASURES: Adjusted odds ratios (AORs) of premature death by external causes in patients with TBI compared with general population controls. RESULTS: Among those who survived 6 months after TBI, we found a 3-fold increased odds of mortality (AOR, 3.2; 95% CI, 3.0-3.4) compared with general population controls and an adjusted increased odds of mortality of 2.6 (95% CI, 2.3-2.8) compared with unaffected siblings. Risks of mortality from external causes were elevated, including for suicide (AOR, 3.3; 95% CI, 2.9-3.7), injuries (AOR, 4.3; 95% CI, 3.8-4.8), and assault (AOR, 3.9; 95% CI, 2.7-5.7). Among those with TBI, absolute rates of death were high in those with any psychiatric or substance abuse comorbidity (3.8% died prematurely) and those with solely substance abuse (6.2%) compared with those without comorbidity (0.5%). CONCLUSIONS AND RELEVANCE: Traumatic brain injury is associated with substantially elevated risks of premature mortality, particularly for suicide, injuries, and assaults, even after adjustment for sociodemographic and familial factors. Current clinical guidelines may need revision to reduce mortality risks beyond the first few months after injury and address high rates of psychiatric comorbidity and substance abuse.