Unintended Consequences of a Medicaid Prescription Copayment Policy

• Published in: Medical care 2014-05, Vol.52 (5), p.422-427
• Main Authors: Lieberman, Daniel A., Polinski, Jennifer M., Choudhry, Niteesh K., Avorn, Jerry, Fischer, Michael A.
• Format: Article
• Language: English
• Subjects: Antihypertensives; Brand name drugs; Brief Report; Copayments; Deductibles and Coinsurance - economics; Deductibles and Coinsurance - statistics & numerical data; Drug prescriptions; Drug Utilization - statistics & numerical data; Drugs, Generic - economics; Health care costs; Health care expenditures; Health care utilization; Humans; Hypoglycemia; Massachusetts; Medicaid; Medicaid - statistics & numerical data; Medications; Prescription drugs; Prescription Drugs - economics; United States; Value based insurance design
• ISSN: 0025-7079; 1537-1948
• DOI: 10.1097/MLR.0000000000000119

Background and Objectives: Medication copayments can influence patient choices. We evaluated 2 copayment policies implemented by Massachusetts Medicaid incentivizing the use of selected generic medications. Research Design and Measures: In 2009, Massachusetts Medicaid copayments were $1 for generics and $3 for brands. On February 1, 2009, copayments for generic antihypertensives, antihyperlipidemics, and hypoglycemics (target medications) remained at $1, whereas copayments for all nontarget generics increased to $2 (policy #1) and $3 on July 1, 2010 (policy #2). Using state-level, aggregate prescription data, we developed interrupted time-series models with controls to evaluate the impact of these policies on use of target generics, target brands, and nontarget essential medications (defined as medications required for ongoing treatment of serious medical conditions). Results: After policy #1, target generic use increased by 0.93% (P