Impact of Medical Marijuana Policies on Opioid Related Hospitalizations and Emergency Department Visits

Currently thirty-three states and the District of Columbia have passed some form of medical marijuana laws. While clinical effects of marijuana might be still unclear, few studies have examined the association of medical marijuana laws and utilization of healthcare including prescription drugs. However, there is little information on impact of medical marijuana policies on hospitalizations and emergency department (ED) visits. The objectives of this study are to examine the associations between medical marijuana policies and hospitalizations and emergency department visits related to opioids. We utilized hospital discharge data from Healthcare Cost and Utilization Project’s (HCUP) Fast Stats Database. HCUP Fast Stats database provides quarterly rates of opioid-related hospitalizations and ED visits data for every available calendar year between 2005 and 2016 across 47 states and 35 states respectively. Data from HCUP Fast Stats database were merged with state level socio-demographic data and opioid-related state health policy data for the analysis. Analyses were carried out using a difference-in-difference regression approach. Regression results indicate that medical marijuana policies were associated with significant reductions in opioid-related hospitalizations, while it has no significant association with opioid-related ED visits. However, emergency department visits significantly respond to the presence of recreational marijuana policies. These findings indicate possible substitution effects of medical marijuana for opioids, which may lead to reductions in healthcare utilizations related to harms of the opioid epidemic.