Smoking, vaping, eating: Is legalization impacting the way people use cannabis?

Background: In the context of the shifting legal landscape of medical cannabis, different methods of cannabis administration have important public health implications. How medical marijuana laws (MML) may influence patterns of use of alternative methods of cannabis administration (vaping and edibles) compared to traditional methods (smoking) is unclear. The purpose of this study was to determine if the prevalence of use of alternative methods of cannabis administration varied in relation to the presence of and variation in MMLs among states in the United States. Method: Using Qualtrics and Facebook, we collected survey data from a convenience sample of n = 2838 individuals who had used cannabis at least once in their lifetime. Using multiple sources, U.S. states were coded by MML status, duration of MML status, and cannabis dispensary density. Adjusted logistic and linear regression analyses were used to analyze outcomes of ever use, preference for, and age of initiation of smoking, vaping, and edibles in relation to MML status, duration of MML status, and cannabis dispensary density. Results: Individuals in MML states had a significantly higher likelihood of ever use of vaping (OR: 2.04, 99% CI: 1.62-2.58) and edibles (OR: 1.78, 99% CI: 1.39-2.26) than those in states without MMLs. Longer duration of MML status and higher dispensary density were also significantly associated with ever use of vaping and edibles. Conclusions: MMLs are related to state-level patterns of utilization of alternative methods of cannabis administration. Whether discrepancies in MML legislation are causally related to these findings will require further study. If MMLs do impact methods of use, regulatory bodies considering medical or recreational legalization should be aware of the potential impact this may have on cannabis users. (C) 2016 Elsevier B.V. All rights reserved.