Methods: In 6 contiguous East SF Bay cities we surveyed 1,124 adult residents, obtaining information on their frequencies of marijuana, tobacco (cigarettes) and alcohol use, household income, and self-ascribed ethnicity. The survey was conducted in English or Spanish and prior to legalized recreational cannabis sales. Respondents were sampled from 72 neighborhoods stratified by high vs. low median household income and alcohol outlet density. To assure comparability between frequency measures we used ordered categories of (1) no use, (2) monthly or less, (3) more than monthly to three times per week, and (4) more than 3 times per week. Multilevel mixed effect Bayesian hierarchical ordered logit models accounted for measurement artifacts due to site stratification.
Results: The distribution of frequencies of use of the three substances were strikingly different across neighborhood areas and societal groups. Cannabis, tobacco and alcohol were all used more frequently by White respondents. Greater household incomes were associated with more frequent alcohol use, less frequent tobacco use, and bore no relationship to frequencies of cannabis use. No well supported stratification or interaction effects among these measures were observed.
Conclusions: The frequent association of “drug problems” with poor and non-dominant minority populations is not consistently supported by these data. Higher income populations appear to have benefited from California’s efforts at tobacco control. Weak regulation of alcohol makes it widely available in California and residents with more disposable income are much more frequent consumers of alcohol, but not of tobacco or cannabis. Otherwise, non-dominant minority populations consistently use all three retailed drugs less often than Whites.