Medical Cannabis Laws and Opioid Analgesic Overdose Mortality in the United States, 1999-2010
Are medical cannabis laws are associated with significantly lower state-level opioid overdose mortality rates?
Marcus A. Bachhuber, MD1,2,3; Brendan Saloner, PhD3,4; Chinazo O. Cunningham, MD, MS5; Colleen L. Barry, PhD, MPP3,6
JAMA Intern Med. 2014;174(10):1668-1673. doi:10.1001/jamainternmed.2014.400
This goal of this article is to determine the association between the presence of state medical marijuana laws and opioid overdose mortality. Investigation was conducted of medical cannabis laws and state-level death certificate data all 50 States from 1999 to 2010. Three states (California, Oregon, and Washington) had medical cannabis laws effective prior to 1999. Ten states (Alaska, Colorado, Hawaii, Maine, Michigan, Montana, Nevada, New Mexico, Rhode Island, and Vermont) enacted medical cannabis laws between 1999 and 2010. States with medical cannabis laws had a 24.8% lower mean annual opioid overdose mortality rate (95% CI, −37.5% to −9.5%; P = .003) compared with states without medical cannabis laws. Examination of the association between medical cannabis laws and opioid analgesic overdose mortality in each year after implementation of the law showed that such laws were associated with a lower rate of overdose mortality that generally strengthened over time: year 1 (−19.9%; 95% CI, −30.6% to −7.7%; P = .002), year 2 (−25.2%; 95% CI, −40.6% to −5.9%; P = .01), year 3 (−23.6%; 95% CI, −41.1% to −1.0%; P = .04), year 4 (−20.2%; 95% CI, −33.6% to −4.0%; P = .02), year 5 (−33.7%; 95% CI, −50.9% to −10.4%; P = .008), and year 6 (−33.3%; 95% CI, −44.7% to −19.6%; P < .001). In secondary analyses, the findings remained similar.