Pre-existing health conditions and repeat traumatic brain injury.

Objective: To assess and compare the effect of Pre-existing epilepsy/seizure disorder and drug/alcohol problem on the hazard of repeat traumatic brain injury (TBI) in persons with TBI who participated in a follow-up study.

Design: Retrospective cohort.

Setting: Acute care hospitals in South Carolina.

Participants: Participants were from the South Carolina Traumatic Brain Injury Follow-up Registry cohort of persons (N=2118) who were discharged from an acute care hospital in South Carolina and who participated in a year-1 follow-up interview.

Interventions: Not applicable.

Main Outcome Measures: Repeat TBI was defined by 2 isolated events of TBI in the same person at least 72 hours apart and recorded in hospital discharge or emergency department records from 1999 through 2005.

Results: A Cox proportional hazards model was used to assess the associations of Pre-existing epilepsy/seizure disorder and drug/alcohol problem with time to repeat TBI, controlling for other confounding factors. There were 2099 persons with information on both Pre-existing conditions. There were 147 (7%) persons who sustained repeat TBI after recruitment to the follow-up study, and 82 (3.9%) had a previous TBI before recruitment for which they were seen in the hospital discharge or emergency department since 1996. The hazard of repeat TBI for persons with Pre-existing epilepsy/seizure disorder was 2.3 times the hazard for those without (hazard ratio, 2.3; 95% confidence interval, 1.2-4.4; P=.011). Pre-existing drug/alcohol problem was not associated with repeat TBI. Other variables significantly associated with repeat TBI were having a prior TBI, being insured under Medicaid, and having no insurance.

Conclusions: Pre-existing epilepsy/seizure disorder predisposes to repeat TBI. Appropriate management of seizure control may be an important strategy to allay the occurrence of repeat TBI.