Marisa Domino, Ph.D., Principal Investigator
Timothy S. Carey, M.D., Co-Investigator
Betsy Sleath, Ph.D., Co-Investigator
Bradley C. Martin, PharmD., Ph.D. (University of Arkansas for Medical Sciences), Co-Investigator
Over the past 20 years, major advances in the treatment of hypertension, diabetes, and other chronic conditions have led to improved outcomes, with adherence to medications often improving quality of life for persons with chronic disease and decreasing total medical costs. Nevertheless, in times of perceived fiscal crises, public and private health insurers often first modify prescription drug benefits using cost containment strategies such as increased use of drug formularies, restrictions on the number of active prescriptions, and restrictions on days’ supply with little understanding of these strategies’ impact on costs or quality. This Health Care Financing & Organization (HCFO) study will examine the impact of the 34-day pharmacy supply limit introduced in North Carolina’s Medicaid program in July 2001.
The researchers will use claims data to examine adherence, utilization, and cost of anti-hypertensives, anti-diabetic medications, lipid-lowering drugs, anti-psychotics, anti-depressants, and seizure-disorder medications among individuals with chronic conditions. The experience in North Carolina will be compared with the experience in Georgia, where there was no change in the days’ supply requirements during the study period. The researchers will utilize a pre-post, differences-in-differences approach, and will control for population and policy differences between states. The study is intended to inform public and private sector initiatives to constrain pharmaceutical costs, suggesting directions for future research to advance the understanding of how prescription drug policies may affect patient behavior, care processes, and costs in Medicaid beneficiaries and other insured populations.
Over the past fifteen years, the majority of health insurance plans, including state Medicaid programs, have imposed maximum day supply limits. However, there is no evidence about this policy’s effectiveness in reducing costs or its impact on medication adherence, which could put patients at risk of greater use of emergency, hospital, and nursing home care, negating the cost savings that the policy change aimed to achieve. Understanding these effects will be especially important in light of the Medicare prescription drug program implemented January 1, 2006, since the individual plans have considerable room to customize the benefit design, but are not at risk for changes in other types of health care costs that could result.