State Medical Cannabis Policy Implementation and Racial Disparities in Opioid Prescribing Among Medicare...

U.S. cannabis policies have a history of racial disparities, highlighting the need for research surrounding racial inequities, particularly within the context of medicalization of cannabis and opioid prescribing. This study evaluated racial disparities in the relationship between state-level medical cannabis policy implementation and changes in opioid-prescribing patterns among Medicare beneficiaries.

Utilizing Medicare claims data from 2012 to 2015, beneficiaries aged ≥65 years were categorized into 3 state categories: Medical marijuana law implementation states, existing medical marijuana law states, and nonmedical marijuana law states. A difference-in-difference analysis was used to determine whether race moderated the relationship between medical cannabis policy implementation and opioid doses filled before and after policy implementation.

A total of 449,336 Medicare beneficiaries were included in the study, comprising 387,713 White individuals (86.3%) and 61,623 racial minority individuals (13.7%). Nearly half of all (49.3%) beneficiaries received at least 1 opioid prescription. White individuals were significantly more likely to receive at least 1 opioid prescription than racial minorities (49.7% vs 46.8%, p<0.001). Morphine milligram equivalent per patient per month significantly increased for both White and racial minority individuals in all state categories, except for racial minority individuals in the medical marijuana law states. There were no significant differences in opioid-prescribing changes between White and racial minority individuals between state categories.

The study found no clear indication of racial disparities in the impact of medical cannabis policies on opioid prescribing. Future research should focus on access to medical cannabis and prescriber attitudes toward treating racial minority patients experiencing pain with cannabis.