Recreational marijuana legalization and prescription opioids received by Medicaid enrollees.

TitleRecreational marijuana legalization and prescription opioids received by Medicaid enrollees.
Publication TypeJournal Article
Year of Publication2019
AuthorsShi Y, Liang D, Bao Y, An R, Wallace MS, Grant I
JournalDrug Alcohol Depend
Volume194
Pagination13-19
Date Published2019 01 01
ISSN1879-0046
KeywordsAnalgesics, Opioid, Drug Utilization, Female, Humans, Legislation, Drug, Male, Marijuana Use, Medicaid, Medical Marijuana, Opioid-Related Disorders, Prescription Drugs, Risk Factors, United States
Abstract

OBJECTIVES: Medical marijuana use may substitute prescription opioid use, whereas nonmedical marijuana use may be a risk factor of prescription opioid misuse. This study examined the associations between recreational marijuana legalization and prescription opioids received by Medicaid enrollees.

METHODS: State-level quarterly prescription drug utilization records for Medicaid enrollees during 2010-2017 were obtained from Medicaid State Drug Utilization Data. The primary outcome, opioid prescriptions received, was measured in three population-adjusted variables: number of opioid prescriptions, total doses of opioid prescriptions in morphine milligram equivalents, and related Medicaid spending, per quarter per 100 enrollees. Two difference-in-difference models were used to test the associations: eight states and DC that legalized recreational marijuana during the study period were first compared among themselves, then compared to six states with medical marijuana legalized before the study period. Schedule II and III opioids were analyzed separately.

RESULTS: In models comparing eight states and DC, legalization was not associated with Schedule II opioid outcomes; having recreational marijuana legalization effective in 2015 was associated with reductions in number of prescriptions, total doses, and spending of Schedule III opioids by 32% (95% CI: (-49%, -15%), p = 0.003), 30% ((-55%, -4.4%), p = 0.027), and 31% ((-59%, -3.6%), p = 0.031), respectively. In models comparing eight states and DC to six states with medical marijuana legalization, recreational marijuana legalization was not associated with any opioid outcome.

CONCLUSIONS: No evidence suggested that recreational marijuana legalization increased prescription opioids received by Medicaid enrollees. There was some evidence in some states for reduced Schedule III opioids following the legalization.

DOI10.1016/j.drugalcdep.2018.09.016
Alternate JournalDrug Alcohol Depend
PubMed ID30390550
PubMed Central IDPMC6318121
Grant ListP30 DA040500 / DA / NIDA NIH HHS / United States
P30 MH062512 / MH / NIMH NIH HHS / United States
R01 DA042290 / DA / NIDA NIH HHS / United States
Division: 
Health Policy & Economics
Category: 
Faculty Publication