The association between number of antiepileptic drug pills taken per day and health care costs among patients with epilepsy in the United States

BACKGROUND:
Epilepsy is a common chronic neurological disorder affecting more than 2.2 million individuals in the United States (U.S.) and has a significant impact on medical expenditure. Lower pill burden has been associated with decreased health care costs in several therapeutic areas, and its impact among patients with epilepsy needs to be assessed.

OBJECTI VE: This study evaluated the impact of the number of antiepileptic drug (AED) pills per day at initiation of monotherapy on health care costs among patients with epilepsy in a large real-world setting.

METHODS: A retrospective analysis of the large U.S. commercial claims IMS PharMetrics Plus database (January 1, 2006-December 31, 2011) was conducted to assess the impact of AED pill burden, defined as the number of AED pills per day, on health care costs in adults with epilepsy. Patients aged 18-65 years with ? 2 epilepsy diagnoses and ? 2 AED prescription claims were selected for study inclusion. The date of the first AED monotherapy claim was defined as the index date. Patients were required to have at least 6 and 12 months of continuous health plan enrollment before and after their index date, respectively. The relationship between index AED pill burden and annual health care costs as well as adjusted annual costs for all-cause and diseaserelated costs were estimated from generalized linear models.

RESULTS: Of the 53,338 study patients, 13.2%, 37.6%, 20.8%, and 28.4% had 1, 2, 3, and > 3 AED pills per day at initiation of an AED monotherapy, respectively. After adjusting for confounders, an AED pill burden of > 3 pills per day was associated with a 6.7% increase in total annual health care costs compared to patients with 1 AED pill per day (P < 0.001). Disease-related annual health care costs among patients with index AED pill burdens of 2, 3, and > 3 AED pills per day were 13.3%, 23.9%, and 38.3% higher, respectively, compared to 1 AED pill per day (P < 0.001). The adjusted total and epilepsy-related mean per-person annual health care costs were estimated at $22,619 and $4,890, respectively. For patients initiating a 1, 2, 3, and > 3 pills per day AED monotherapy, adjusted mean per-person annual health care costs were estimated at $21,974, $23,280, $23,049, and $21,730, and adjusted mean per-person epilepsy-related health care costs were estimated at $3,776, $5,483, $4,106, and $5,195, respectively.

CONCLUSIONS: In this study, patients initiating an AED prescribed as a single pill per day incurred lower health care costs during the year following monotherapy initiation than patients with greater pill burdens.