Abstracts

Rationale: This study evaluated the impact of monotherapy antiepileptic drug (AED) pill burden at treatment initiation on health care resource use among patients with epilepsy in a large real-world setting in the United States.Methods: A retrospective analysis of a large commercial claims database (January 1, 2006, to December 31, 2011) was conducted to assess AED pill burden (defined as the number of pills taken by the patient) at monotherapy initiation and its impact on inpatient hospital admissions and emergency department visits in adults with epilepsy. Patients aged 18-65 years with ≥2 epilepsy diagnoses and ≥2 AED prescription claims, with at least 6 and 12 months of continuous health plan enrollment before and after their index date were selected for study inclusion. The first monotherapy AED claim defined the index date. Poisson regression models were used to assess the relationship between index pill burden and annual rates of epilepsy-related hospital admissions and emergency department visits.Results: The 53,338 study patients were prescribed an average of 3 pills per day, and 13.2%, 37.6%, 20.8%, and 28.4% had 1, 2, 3, and >3 pills per day at AED monotherapy initiation, respectively. After adjusting for confounders, patients on 2, 3, and >3 pills/day, compared to those on 1 pill/day, had incremental annual inpatient hospital admissions of 12.5%, 23.1%, and 19.4% respectively. Similarly, incremental annual emergency department visits during the year following monotherapy initiation were 15.5%, 25.2%, and 15.1% among them.Conclusions: Patients initiating an AED prescribed as a single pill per day had fewer inpatient hospital admissions and emergency department visits than patients with larger pill burdens during the year following monotherapy initiation. Future research into the reasons for this association is warranted.