Generic levothyroxine initiation and substitution among Medicare and Medicaid populations: a new user cohort study

Generic levothyroxine has been approved and available since 2004 but its substitution remains controversial. Therefore, the objective was to examine patterns of and identify factors associated with initiation and substitution of generic levothyroxine treatment. This was a retrospective observational study, including new users of brand and generic levothyroxine in 2013–2015 Medicare (n = 15,877) or 2011–2012 Medicaid (n = 9390) administrative...