Introduction:

Most Americans now live in states that have a medical marijuana dispensary. Increases in the number of patients enrolled in medical marijuana programs nationally between 2016 and 2020 parallel a steady increase in the number of qualifying conditions (QC) with limited to no evidence. Like other states, Pennsylvania’s medical marijuana program has experienced rapid expansion since its inception in 2017, with the number of enrolled patients surging from 1,230 in 2017 to 432,717 in 2023.

Research Question:

To what extent were certifications in the Pennsylvania medical marijuana (MMJ) program evidence-based?

Methods:

QCs, zip-codes, and certification dates for each MMJ patient from 2017-2023 were obtained from the Pennsylvania Department of Health and the US Census Bureau's Population Estimates Program (PEP) datasets. Using the NAS 2017 report, Pennsylvania’s 21 QCs were categorized as either evidence-based (substantial to conclusive evidence) or not evidence-based (limited to no evidence).

Results:

In 2017, 67.6% of enrolled MMJ patients had at least one evidence-based condition. Following the addition of anxiety disorders as a QC in 2019, we observed a continuous decline in the share of evidence-based certifications. In 2023, 41.1% of patients had at least one evidence-based QC. From 2017-2019, the most common patient was certified for only chronic pain (37.3%-46.5%). From 2020-2023, patients having only anxiety disorders were the most common MMJ patient (31.7%-43.5%).

Conclusion:

The decrease in the proportion of evidence-based MMJ certifications from 2019-2023 indicates that national patterns between 2016-2020 extend into 2023 for the Pennsylvania MMJ program. Given that evidence-based medicine is the gold standard, there is a need for further research into the impacts of marijuana on anxiety disorders, for lawmakers to re-evaluate QCs, and for providers to more rigorously make MMJ certifications.