Impact of US federal and state generic drug policies on drug use, spending, and patient outcomes: A systematic review

Background: Prescription drugs contribute to increased healthcare expenditures in the United States (U.S.). Use of generic drugs has been recognized as an effective tool to control rising prescription drug costs. This study aimed to evaluate the impact of U.S. federal and state generic drug policies on drug use, spending, and patient outcomes. Methods: A systematic search was performed in June 2017, using PubMed, Web of Science, PsycINFO, and Business Source Premier. Search was limited to published articles in English language, including human subjects in the U.S., and with at least one outcome measure related to health service utilization, spending, or patient outcomes. Results: Thirty-four studies constituting seven key policy domains were included. Medicaid/Medicare Prior Authorization (PA) policies (n = 4) led to increased generic use, reduced patient and payer's spending on prescriptions without causing deterioration in patient's health-related quality of life. Medicare prescription plan's generic drug benefits (n = 4) had impact on increased generic use and generated savings, but the limited access to branded drugs may increase medication use gaps and risks of hospitalizations. State generic substitution laws (n = 3) caused increased generic use and cost savings for both consumers and states. Medicare/Medicaid coverage cap policies (n = 3) were associated with increased patient's out-of-pocket spending (OOP) and reduced prescription spending for payers. Policies lowering cost-sharing (n = 7) were associated with increased patient's medication use and adherence, but the impact varied by therapeutic classes. Existing evidence evaluating Medicare Part D (n = 12) suggested decreased prescription spending for beneficiaries and Medicare. Generic gap coverage reduced patient's OOP and Medicare spending. Finally, early evidence showed reduced consumers' OOP prescription spending after the ACA (n = 2). Conclusions: Federal and state policies regarding generic drugs have resulted in reduced spending for consumers and payers. However, the overall impact on patient outcomes remains unclear.