Article by Judy George, MedPage Today
Access to legal cannabis stores was linked with fewer opioid deaths in the U.S., a new analysis suggested.
The number of marijuana dispensaries in a county was negatively related to log-transformed opioid mortality rate, adjusted for age (β -0.17, 95% CI -0.23 to -0.11), reported Balázs Kovács, PhD, of Yale University School of Management in New Haven, Connecticut, and Greta Hsu, PhD, of University of California Davis Graduate School of Management.
This means that increasing the number of storefront dispensaries from one to two was tied to a 17% reduction in death rates of all opioid types, and an increase from two to three stores was associated with a further 8.5% reduction in mortality, Kovács and Hsu noted.
The relationship was stronger — leading to an estimated 21% drop in mortality — when only deaths from synthetic non-methadone opioids like fentanyl were considered (β -0.21, 95% CI -0.27 to -0.14), they wrote in The BMJ.
“We find this relationship holds for both medical dispensaries, which serve only patients who have a state-approved medical card or doctor’s recommendation, as well as for recreational dispensaries, which sell to adults 21 years and older,” Kovács said.
As business school researchers, Kovács and Hsu first became interested in the increasing prevalence of legal cannabis stores as an organizational issue.
“We tracked evolving cannabis markets across the U.S. from 2014 onwards in an effort to understand how this new category of organizations emerged,” Kovács told MedPage Today. “We realized, however, that our county-level database could also be used to examine whether the availability of legal cannabis in an increasing number of geographic areas has any implications for opioid misuse.”
Their findings add to a mixed evidence base about the relationship between legal marijuana and opioid overdoses. In 2014, an analysis suggested that states with medical cannabis laws experienced slower increases in opioid overdose mortality. However, a subsequent study showed that those findings didn’t hold over a longer period, and that associations between state medical cannabis laws and opioid-related mortality reversed direction and remained positive after accounting for recreational cannabis laws.
Kovács and Hsu based their analysis on data from 812 counties in 23 states (plus the District of Columbia) that allowed legal cannabis dispensaries to operate by the end of 2017. They combined 2014-2018 CDC mortality data with census data and storefront information from Weedmaps, collecting data on dispensaries operating within each county on a monthly basis from 2014 to December 2017. Mortality analysis focused on deaths of people 21 and older.
Eight states and the District of Columbia allowed for recreational storefronts; 15 allowed for medical dispensaries only. An increase from one to two medical dispensaries led to an estimated 15% mortality rate reduction in the study; an increase from one to two recreational dispensaries led to an 11% drop.
Two points about this analysis need to be considered, noted Sameer Imtiaz, PhD, of the Institute for Mental Health Policy Research in Toronto, and colleagues, in an accompanying editorial.