Neurological and Psychological Sequelae and Healthcare Utilization Patterns of Older US Adults with Repetitive Traumatic Brain Injury

Abstract

Background: Traumatic brain injury (TBI) is a leading cause of injury-related death and disability among older adults. Older adults experience adverse health outcomes and increased healthcare utilization following TBI. Additionally, they are at risk of repetitive TBI, which may compound health problems and increase resource utilization further. However, little is known about repetitive TBI among older adults. Objective: To identify incidence, predictors, and outcomes of repetitive TBI. Specifically, I investigated the association between repetitive TBI and depression, ischemic stroke, Alzheimer’s disease and related dementias (ADRD), and insomnia. In addition, I assessed healthcare utilization following repetitive TBI in inpatient, outpatient, and emergency department settings. Methods: I conducted a retrospective cohort study of a 5% sample of US Medicare beneficiaries greater than or equal to 65 years of age. I estimated incidence of and identified risk factors for repetitive TBI using a log-binomial model. Repetitive TBI was identified as another diagnostic code for TBI occurring >90 days after the index TBI. Associations between repetitive TBI and selected outcomes were assessed using a discrete time model with a complementary log-log link. Negative binomial models were used to assess healthcare utilization associated with repetitive TBI. Results: Among 38,064 beneficiaries in the sample, annual incidence of repetitive TBI was 3%. Age, epilepsy, Parkinson’s disease, ADRD, depression, and atrial fibrillation were associated with increased risk of repetitive TBI. Incidence of depression and ADRD was elevated following single TBI, and was even more elevated following repetitive TBI. Healthcare utilization was significantly higher in those with repetitive TBI, beyond single TBI, across all points of service. Conclusions: In this sample of older adult Medicare beneficiaries, I found 3% annual incidence of repetitive TBI and identified factors associated with repetitive TBI. Additionally, I found that repetitive TBI was associated with increased risk of depression and ADRD and increased healthcare utilization that was even greater than the risk observed with single TBI. Targeting interventions to reduce the occurrence of repetitive TBI in older adults could reduce risk of these adverse health outcomes and inform healthcare utilization.