Factors Associated With Prescriptions for Branded Medications in the Medicare Part D Program

Abstract

Promoting the use of generics—the lower-priced and therapeutically equivalent versions of branded drugs—is an important approach to contain health care spending in the US.1-5 The US Department of Health and Human Services estimated that, if all branded drugs with generic equivalents had been dispensed with a generic in the Medicare Part D program, the program and its beneficiaries would have saved $2.8 billion in 2016.6 Since 1984, all states and the District of Columbia have enacted laws to promote generic dispensing, either through mandatory substitution (pharmacists must dispense generics when filling a branded prescription) or permissive substitution (pharmacists have the option to dispense generics).4,7,8 However, the instruction of prescribers, the preference of patients, and other reasons such as the unavailability of a generic may override state substitution laws.4,8,9 The specific reason for dispensing a given product is documented through product selection codes, also known as dispense-as-written (DAW) provisions (Table 1). Physicians may indicate DAW provisions on their prescriptions or pharmacists may document such provisions when they file the drug claim.10