Background and aims

While the United States has been experiencing an opioid epidemic, 29 states and Washington DC have legalized cannabis for medical use. This study examined whether state-wide medical cannabis legalization was associated with reduction in opioids received by Medicaid enrollees.

Design

Secondary data analysis of state-level opioid prescription records from 1993-2014 Medicaid State Drug Utilization Data. Linear time-series regressions assessed the associations between medical cannabis legalization and opioid prescriptions, controlling for state-level time-varying policy covariates (such as prescription drug monitoring programs) and socio-economic covariates (such as income).

Setting

United States.

Participants

Drug prescription records for patients enrolled in fee-for-service Medicaid programs that primarily provide health-care coverage to low-income and disabled people.

Measurements

The primary outcomes were population-adjusted number, dosage and Medicaid spending on opioid prescriptions. Outcomes for Schedule II opioids (e.g. hydrocodone, oxycodone) and Schedule III opioids (e.g. codeine) were analyzed separately. The primary policy variable of interest was the implementation of state-wide medical cannabis legalization.

Findings

For Schedule III opioid prescriptions, medical cannabis legalization was associated with a 29.6% (P = 0.03) reduction in number of prescriptions, 29.9% (P = 0.02) reduction in dosage and 28.8% (P = 0.04) reduction in related Medicaid spending. No evidence was found to support the associations between medical cannabis legalization and Schedule II opioid prescriptions. Permitting medical cannabis dispensaries was not associated with Schedule II or Schedule III opioid prescriptions after controlling for medical cannabis legalization. It was estimated that, if all the states had legalized medical cannabis by 2014, Medicaid annual spending on opioid prescriptions would be reduced by 17.8 million dollars.

Conclusion

State-wide medical cannabis legalization appears to have been associated with reductions in both prescriptions and dosages of Schedule III (but not Schedule II) opioids received by Medicaid enrollees in the United States.

Background

Since early 2016, an increasing number of states passed legislations that limit the duration and/or dosage of initial opioid prescriptions or opioids for acute pain.

Objective

The objective of this study was to assess changes in the number of opioid prescriptions covered by Medicaid and received by Medicaid patients associated with state implementation of legislative limits on initial opioid prescriptions.

Research design

We explored the natural experiment resulting from the staggered implementation of state legislative limits. The analysis adopted a Difference-in-Differences framework and controlled for other major state policies bearing implications for prescription opioid use. The main analysis included 26 states that implemented limits from early 2016 to late 2018. A secondary analysis included all 50 states and the District of Columbia.

Measures

Population-adjusted state-quarter level counts of Schedule II and III opioid prescriptions received by Medicaid patients, based on data from the Medicaid State Drug Utilization Data and state Medicaid enrollment reports for 2013-2018.

Results

Implementation of legislative limits on initial opioid prescriptions was associated with a 7% reduction in the number of opioid prescriptions per 100 Medicaid enrollees. Such reduction was largely attributable to a reduction in Schedule II opioid prescriptions. Secondary analysis by including all jurisdictions and sensitivity checks supported the robustness of results.

Conclusion

The recent implementation of state legislative limits on initial opioid prescriptions was associated with meaningful reductions in the volume of Schedule II opioid prescriptions received by Medicaid patients.

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.