The Cannabis Retail Environment for Young Adults in Los Angeles: Which Metrics Matter

Background: Currently, there is no consensus on how to measure cannabis retailer density. Researchers and policy makers need clear measures to support policies that mitigate unintended harms of legalization. To address this gap, our unique study leverages cannabis retailer location data in Los Angeles County (LA), California, and home addresses from an LA-based cohort of young adults (21-25 years) to develop a series of cannabis retailer density metrics and assess their relationship with cannabis use. Methods: Drawing from GIS-based measures of alcohol outlet density, we developed a series of cannabis retailer density metrics: proximity, counts within 5- 10- 15-, and 30-minute driving distances, and considered retail licensure. Retailer addresses were compiled by webscraping cannabis registries (e.g. Weedmaps) and conducting field visits (March 2019). Home addresses were geocoded for participants who completed a 2019 survey (n 1097). A series of retailer metrics was created for each person. We fit a series of multi-level logistic regression models with a random intercept by census tract (CT) (models adjusted for age, gender, race/ethnicity, college student, and CT median household income) to assess which retailer metrics were associated with any past month cannabis use. Results: Thirty percent of participants used cannabis in the past month, and 430 retailers were operating in LA in 2019. Thirty-nine percent of participants had a retailer within a mile from home and an average of 14 retailers within a 10-minute drive. Licensed retailers were less prevalent; the nearest licensed retailer was on average 2.4 miles from home. The odds of past month cannabis use significantly increased by 3% (OR:1.03, 95% CI:1.00–1.07) for every additional licensed retailer within a 10-minute drive in adjusted model; use was also significantly associated with licensed retailers within a 30-minute drive (OR:1.01, 95% CI:1.00–1.01). Proximity metrics were not significantly associated with past month cannabis use.