Abstracts

Rationale: A large body of scientific research has consistently established mood disorders, anxiety, and psychoses, among other mental health conditions (MHC) as frequent comorbidities of epilepsy. However, the extent of incremental healthcare service use and costs due to MHC in patients with epilepsy has not been investigated. This retrospective cohort analysis of health plan claims compared healthcare use and costs among adult patients with partial onset seizures (POS) with and without comorbid MHC. Methods: We utilized the Inovalon MORE2 Registry, longitudinal data from >150 commercial, Medicare Advantage, and managed Medicaid health plans. Adult POS patients were identified using ICD9/10 diagnosis codes with no evidence of other seizure conditions who were continuously enrolled in a plan 6-months pre/12 months post-POS diagnosis. MHC were defined as diagnoses for anxiety, bipolar condition/mania, attention-deficit conduct condition, major depression, schizophrenia and other psychotic conditions prior to POS. Patients without MHC were propensity-score matched to patients with pre-existing MHC on baseline patient characteristics. The assessment examined a series of primary utilization and cost outcomes, including: 1) direct healthcare resource utilization (hospitalizations, emergency department visits, outpatient services, office visits, pharmacy, etc.); and 2) total provider reimbursement.  Results: The final propensity score-matched cohort included 17,566 patients for both POS patients with and without MHC. Patients with pre-existing MHC were more likely to receive adjunctive epilepsy therapy (26.5% vs. 18.6%, p<0.001) as well as broad-spectrum anti-epileptic drugs (75.6% vs. 54.3%, p<0.001). Additionally, patients with POS and MHC were significantly more likely to utilize high-cost healthcare services. The odds of an ED visit and hospitalizations in the 12-month follow-up period were 48% (p<0.001) and 61% (p<0.001) higher, respectively, among patients with POS and MHC. Furthermore, presence of MHC lead to approximately 50% greater utilization of ED, physician, and inpatient services. As a result, direct healthcare expenditures were significantly higher among patients with POS and a MHC ($17,596 vs. $10,857; 62% higher, p<0.001), with the trend consistent across all care settings. Conclusions: A consistent body of clinical research suggests that patients with epilepsy are often afflicted with MHC that may be present prior to a diagnosis of epilepsy or that may arise following a diagnosis of epilepsy, due to patients' changing medical and life circumstances. Our analysis builds upon this clinical knowledge to illustrate the health service utilization and cost implications of MHC among a population of patients with POS. The data clearly suggest that compared to patients without MHC, patients with pre-existing MHC have greater healthcare resource use and expenditures across all healthcare settings. Funding: SK Life Science Inc.