In all NESARC and NSDUH analyses, we adjusted for a series of state-level characteristics that might have differed between states that legalized vs. those that did not legalize medical marijuana, and that might also relate to marijuana use and abuse/dependence, including the proportion of state residents who were male, white or other race/ethnicity, without a high school diploma, and under 30 years of age (Subramanian and Kawachi, 2004). These covariates were obtained for the year 2004 from the American Community Survey (ACS) [http://factfinder.census.gov/], which provides publicly available estimates of state populations ascertained between the decennial census excluding populations living in institutions, college dormitories, and other group quarter facilities.
