Prevalence and Correlates of Cannabis Use in Massachusetts after Cannabis Legalization and before Retail Sales.

We determined the prevalence and correlates of cannabis use in Massachusetts after recreational use was passed, but before recreational cannabis stores opened. A cross-sectional, population-based survey of Massachusetts adults, age 18 years or older, (n = 3,022) was conducted in November-December, 2017. We estimated population-level prevalence and correlates of past 30-day cannabis use. 21.1% [95% CI: 18.6, 23.6] of Massachusetts adults reported past 30-day cannabis use. Among cannabis users, 56.0% [CI 49.1, 62.9] reported non-medical cannabis use, 15.5% [12.1, 18.9] reported medical cannabis use, and 28.5% [CI 22.3, 34.8] reported both types of use. Men were more likely than women to use cannabis (Risk Ratio: 1.3 [CI 1.1, 1.6]), as were young adults (18-25 years old), those with lower socioeconomic status, non-parenting individuals, those who used alcohol (1.9 [CI 1.4, 2.6]) or other substances (1.7 [CI 1.3, 2.4]), and residents of Western Massachusetts (2.0 [1.3, 3.0]; ref: Boston area), the Northeast (1.8 [CI 1.2, 2.7]), and the Southeast (1.8 [CI 1.1, 2.7]). Cannabis is widely used in Massachusetts, with varying prevalence rates by gender, age, socioeconomic status, poly-substance use, and region. Findings may inform public health efforts and serve as a baseline for measuring health and social impacts of opening retail cannabis stores.