Abstracts

Rationale: About 2.87 million Americans experience a traumatic brain injury (TBI) each year. In 2013 there were over 280,000 hospitalizations for TBI in the US. A CDC-funded study found that among people aged 15 years and older, about 1 out of 10 developed epilepsy in the 3 years following a TBI that required hospitalization. The classification of post-traumatic seizures (PTS) depends on the duration between TBI and first seizure, it is categorized by early post-traumatic seizure (up to 7days) and late post-traumatic seizure (>7days). The incidence of early seizures after TBI is reported to be between 2.6% and 16.3%. Concurrent, TBI and epilepsy not only increase mortality and morbidity but also drastically increase the risk of disability and rehabilitation related expenses. Many studies had published focusing on mortality but information on disability and healthcare burden is lacking.We aimed to find out prevalence, disability, discharge disposition, and cost of hospitalization due to post-TBI epilepsy. Methods: We performed a retrospective analysis of the Nationwide Inpatient Sample (NIS) (years 2003-2014) in adult hospitalizations for primary diagnosis with TBI to find out epilepsy and post-traumatic seizures using ICD-9-CM codes. We performed weighted analyses using Chi-square and paired students’ t-test to compare the outcomes- disability, discharge disposition and cost of hospitalization amongst epilepsy and non-epilepsy patients. The comparison of disability/loss of function was investigated by All Patient Refined Diagnosis Related Groups (APR-DRGs) severity, using software developed by 3M Health Information Systems, where score 1 indicates minor loss of function, 2-moderate, 3-major, 4-extreme loss of function. Discharge outcome was measured by discharge to home vs non-home (Short term hospital/Skilled Nursing Home/ Intermediate care/ Home Health Care). Multivariate survey logistic regression analysis was done to evaluate the outcomes of epilepsy amongst TBI hospitalization. Outcomes were adjusted with patients’ demographics (age, gender, race), hospital (hospital region, teaching versus nonteaching hospital, hospital bed size), and admission (admission day, primary payer, admission type, Median Household Income Category) related characteristics, comorbidities (hypertension, diabetes mellitus, hypercholesterolemia, obesity, smoking status, drug abuse, alcohol abuse, psychiatric disorders, and neurological comorbid conditions) and Charlson's co-morbidity index. Results: Between the years 2003 to 2014, total 1,819,423 patients with TBI were hospitalized. Out of them, 72446 (3.98%) patients had epilepsy or post-traumatic seizure. Amongst TBI hospitalizations, patients with epilepsy had a higher prevalence of major or extreme loss of function on discharge (47.22% vs 34.31%; p<0.0001) and discharge to non-home (54.15% vs 42.98%; p<0.0001). The mean cost of hospitalization ($85,463 vs $63,243; Cost diff: + $22,220; p<0.0001) was higher among patients with epilepsy with higher utilization of Medicare (51.07% vs 42.42%; p<0.0001) and Medicaid (15.42% vs 8.86%; p<0.0001) compared to patients without epilepsy. In the multivariable regression model, post-traumatic epilepsy and seizure were associated with higher odds of having a major/severe disability [Odds Ratio (OR):1.20; Confidence Interval (CI):1.15-1.25] and discharge to the rehabilitation facility (OR:1.31; CI:1.26-1.36). Conclusions: This study has shown that post-TBI epilepsy increased the burden of disability and healthcare cost. This information provides the rationale to focus on early and appropriate management of post-traumatic seizures. It also supports the need for research to obtain disease-modifying interventions during the latent period between TBI and onset of epilepsy. Funding: No funding