Going Green – The Relationship Between Medical Marijuana Policy Implementation and Opioid Prescribing Patterns
Date of Award
Ph.D. in Pharmaceutical Sciences
University of Mississippi
The objectives of this dissertation are: 1) To measure the prevalence of medical marijuana use in the U.S. and to identify predictors of medical marijuana use; 2) To measure opioid prescribing patterns among Medicare beneficiaries within states following the implementation of medical marijuana policies and to compare opioid prescribing patterns among Medicare beneficiaries residing within these states compared to individuals within states without medical marijuana policies in place; and 3) To determine if racial disparities exist in the effect of medical marijuana policy implementation on opioid prescribing patterns among Medicare beneficiaries.
A retrospective secondary database analysis was conducted utilizing five years of the National Survey on Drug Use and Health (NSUDH). A multivariable logistic regression model assessed the association between prescription pain reliever use and medical marijuana in the adult U.S. population while adjusting for substance use factors, psychiatric factors, and demographic characteristics. A difference-in-difference fixed effects linear regression model assessed the impact of medical marijuana policy implementation on opioid prescribing rates among Medicare enrollees by comparing changes in prescribing levels in the year following a state-level medical marijuana policy implementation versus states with no medical marijuana laws and states with existing laws. Lastly, an additional difference-in-difference analysis was conducted, stratified by race, to determine racial disparities.
Within the U.S. adult population from 2015 to 2019, medical marijuana use prevalence increased from 1.6% to 2.4%, while appropriate prescription pain reliever use decreased from 33.4% to 27.5%, and misuse decreased from 4.7% to 3.7%. Past-year medical marijuana users were significantly more likely to use prescription pain relievers appropriately (OR=1.99, p<.001) and misuse (OR=1.94, p<.001). Among Medicare enrollees in the year following a medical marijuana policy implementation, opioid prescribing levels per patient increased by 98.3 MME. However, the increase in opioid prescribing levels observed in the comparator states was significantly greater, with an increase of 198.2 MME per enrollee among non-medical marijuana policy states and an increase of 131.1 MME per enrollee among existing medical marijuana policy states. When stratified by race, the difference-in-difference regression model found no within-state racial disparities in changes in opioid prescribing levels between minorities and white individuals within implementation states, nor any between-state racial disparities compared to enrollees residing in non-medical marijuana states or existing medical marijuana states.
The study results show an increase in patients’ willingness to use medical marijuana to treat pain in place of prescription opioids, along with the need for policy expansions in states with no medical marijuana availability. Medical marijuana is a potential solution to combating increases in opioid prescribing rates but should be initiated with other long-term strategies. No racial disparities were found within states that implement a new medical marijuana policy, nor were there any racial disparities found when making comparisons between states with new medical marijuana policies versus states without medical marijuana laws and states with existing laws. However, government entities must move forward with medical marijuana policies with mindfulness regarding how previous marijuana policies negatively impacted the minority population.
Dunn, Tyler James, "Going Green – The Relationship Between Medical Marijuana Policy Implementation and Opioid Prescribing Patterns" (2022). Electronic Theses and Dissertations. 2429.