The association between antiepileptic drug dosing frequency at monotherapy initiation and direct health care costs in the United States

Abstract

OBJECTIVE:
This study evaluated the impact of antiepileptic drug (AED) dosing frequency at monotherapy initiation on health care costs among patients with epilepsy in the United States (US). BACKGROUND: Claims data offer an opportunity to assess the relationship between dosing frequency and health care costs from a real-world perspective.

DESIGN/METHODS:
A retrospective analysis of a large US commercial claims database (January 1, 2006, to December 31, 2011) was conducted to assess AED dosing frequency at monotherapy initiation and its impact 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 first AED claim defined the index date, on which patients were required to have AED monotherapy. Patients were also required to have at least 6 and 12 months of continuous health plan enrollment before and after their index date, respectively. Generalized linear models were used to assess the relationship between index dosing frequency and annual health care costs as well as to estimate adjusted annual costs.

RESULTS:
Of the 53,338 study patients, 11.2[percnt], 58.5[percnt], 30.2[percnt], and 0.1[percnt] were prescribed a once-, twice-, thrice-, and four-times-daily AED at monotherapy initiation, respectively. After adjusting for confounders, twice-, thrice-, and four-times-daily AED initiation were associated with 14.0[percnt], 40.4[percnt], and 62.2[percnt] increases in total annual health care costs compared to once-daily AED initiation. Adjusted total and epilepsy-related mean per-person annual health care costs were estimated at $22,377 and $4,875, respectively. For patients initiating a once-, twice-, thrice-, and four-times-daily AED, the adjusted mean per-person annual health care costs were estimated at $15,385, $21,806, $26,056, and $30,328, respectively.

CONCLUSIONS:
Patients initiating a once-daily AED incurred lower health care costs during the year following monotherapy initiation than patients with greater dosing frequencies. Study Supported by: Sunovion Pharmaceuticals Inc.