Persistence with once-daily versus twice-daily bupropion for the treatment of depression in a large managed-care population.

In this study, the impact of dosing frequency [once daily with bupropion extended-release (XL) versus twice daily with bupropion sustained-release (SR)] on medication persistence was assessed over a 9-month period in a large cohort of patients with depression in a managed-care setting. Administrative claims data from the Integrated Health Care Information Services National Managed Care Benchmark database were analyzed for patients 18 to 64 years old with a documented diagnosis of depression who began treatment with bupropion XL or SR between September 2003 and February 2004. Persistence of use was higher with once-daily bupropion XL (n = 1074) than with twice-daily bupropion SR (n = 1917) across measures assessed by univariate tests of proportions.