Bruce C. Stuart, PhD

There is significant heterogeneity in formulary placement and restrictions on new drug approvals in the Part D marketplace.

Formulary restrictions on brand name noninsulin antihyperglycemic drugs have little impact on treatment intensification patterns among low-income patients with diabetes in Medicare Part D.

Placing formulary restrictions on brand name drugs shifts use toward generics, lowers the cost per prescription fill, and has minimal impact on overall adherence for antidiabetes, antihyperlipidemia, and antihypertension medications among low-income subsidy recipients in Medicare Part D plans.