Medicaid Prescription Drug Use Lower in States With Medical Marijuana

A recent study published in Health Affairs examined the link between state medical marijuana laws and Medicaid prescription drug spending, and found that states with marijuana laws are more likely to have lower prescribing rates for Medicaid prescription drugs.

In order to examine the link between the medical marijuana laws and Medicaid prescription drug spending, researchers identified nine condition groups that can be treated with both FDA-approved drugs and medical marijuana. These condition groups included, anxiety, depression, glaucoma, nausea, pain, psychosis, seizure disorders, sleep disorders, and spasticity.

“While there are no administrative data that can be used to directly examine medical uses of marijuana, it is possible to examine contemporaneous patterns of marijuana and prescription drug use in states that have enacted a medical marijuana law and thus to assess whether patients are substituting medical marijuana for prescription drugs,” Ashley C Bradford and W David Bradford, PhD, both of the department of public administration and policy at the University of Georgia, wrote in their study. “If they are, this would be an indirect indication that medical marijuana has accepted medical uses.”

The researchers used Medicaid prescribing data from all 50 states from between 2007 and 2014, and identified the average doses of FDA-approved prescription drugs dispensed to Medicaid beneficiaries for each of the nine clinical groups. They used statistical analysis based on state laws, and found afterwards that states without a medical marijuana law had higher doses of each drug dispensed to each Medicaid beneficiary. Additionally, researchers performed a multivariate analysis to control the influence of several potential state-level confounders that included median household income, prescription drug monitoring programs, Medicaid expansion, and legalized recreational marijuana.

According to the findings, in five of the nine clinical areas, a significant negative association between the presence of a medical marijuana laws and the average number of prescriptions filled per quarter was identified. The findings suggest that the greatest gap was for drugs used to treat nausea—nausea prescription drugs were prescribed 17% less in medical marijuana states.

However, for the additional four clinical areas—anxiety, glaucoma, sleep disorders, and spasticity—the researchers found no significant association between having a medical marijuana law in place and the amount of filled prescriptions.

Additionally, researchers used data from CMS to calculate the savings that resulted from the lowered use of prescription drugs in the states that allowed medical marijuana. The results suggested that the total Medicaid savings in 2014 totaled $475.80 million—or about 2% of total Medicaid spending.

“The reduced spending in Medicaid that we estimated does not represent a pure change in social welfare (as economists would define it), since some of the estimated savings represented a transfer of costs from the program to its enrollees who chose to pay for marijuana out of pocket,” Ms Bradford and Dr Bradford concluded. “But in times of significant budget pressure, the possible savings of $1.01 billion nationally in spending on prescriptions in fee-for-service Medicaid is significant.”

—Julie Gould (Mazurkiewicz)