Abstracts

Rationale: Many patients with partial onset seizures (POS) can be managed using monotherapy (MT), while refractory patients advance to adjunctive therapy (AT). The present study compares the impact of patients’ antiepileptic drug (AED) mono- or adjunctive therapy on spousal healthcare costs.Methods: This was a retrospective study using the Human Capital Management Systems (HCMS) database of commercially insured subjects. Married US employees and their respective spouses were selected as employee-spouse pairs for further analysis if the spouse had presented in the database with a diagnosis of POS [ICD9-CM=345.4x or 345.5x] between Jan-2001 and Jun-30-2014. Spouses treated with only one AED throughout the observation period were classified as MT users; those with >90 days concomitant use of a second AED were classified as AT users. All patients and their spouses (the employees) were required to have >365 days of continuous eligibility following initial AED use (MT) or start of the second agent (adjunctive). Costs were adjusted to 2014 dollars. The costs, services and likelihood of care for employees with spouses receiving MT vs. AT were compared. Logistic regression was used for likelihood comparisons and two-part regressions (logistic followed by generalized linear models) were used for costs and services comparisons. All models controlled for demographic, job-related variables (e.g., exempt status, salary), location, and the Charlson Comorbidity Index (CCI).Results: Employee-spouse pairs identified 34.9% (n=129) receiving AT and 65.1% (n=238) using MT. In the MT group, mean age for employees and spouses were 45.2 and 44.7 years, respectively; in the AT group, average ages were 44.1 and 43.4 years, respectively. The cohorts were similar in demographic, job-related, and regional comparisons except the AT employees had lower salaries ($63,758 v $73,549, p=0.0341). The costs summed by locations of care identified an annual difference of $2239, p<0.05. Employees whose spouses were managed by AT were 7.8 times more likely to be hospitalized (9.9% v 1.3%, p=0.0016), used 7.4 times more inpatient services (0.29 v 0.04, p=0.0019) and had 36.7 times higher inpatient costs ($1545 v $42, p=0.0005). Both cohorts have similar likelihoods of using the doctor’s office; the employees married to AT spouses, however, used more services (7.23 v 5.68, p=0.0017), had higher office visit costs ($1294 v $968, p=0.0132), and had higher costs ($65 v $23, p=0.0148) in the ‘other’ category, representing care received at home, ambulance, hospice, among others.Conclusions: In this retrospective study, employees whose spouses with partial-onset seizures were managed with adjunctive therapy had significantly higher healthcare costs than employees whose spouses with partial-onset seizures were managed with monotherapy. These differences were present in nearly all cost categories. The findings of this study suggest an increased burden on employees whose spouses are diagnosed with drug-resistant epilepsy.