Density of Medical Marijuana Dispensaries and Current Marijuana Use among Young Adult Marijuana Users in Los Angeles.

Background: While tobacco and alcohol studies have focused on density of outlets as a determinant of consumption, research has begun examining the effects of medical marijuana (MM) dispensaries on marijuana use. Objectives: Examine the relationship between density of MM dispensaries and frequency of marijuana use among young adult medical marijuana patients (MMP) and nonpatient users (NPU). Methods: Young adult marijuana users (n = 329) aged 18- to 26-year old were sampled in Los Angeles in 2014-2015 and separated into MMP (n = 198) and NPU (n = 131). In 2014, 425 operational MM dispensaries were identified within the City of Los Angeles. Sequential multilevel Poisson random effect models examined density of MM dispensaries per square mile and 90 d marijuana use among MMP and NUP at the ZIP code level while controlling for demographic, behavioral, and community characteristics. Results: Density of MM dispensaries was not related to 90 d use of marijuana (days of use or hits per day) among either MMP or NPU. MMP reported significantly greater days of marijuana use in the past 90 d compared to NPU but no differences were found for hits per day. African-Americans reported significantly greater hits per day compared to whites. Hispanics reported significantly fewer hits per day compared to non-Hispanics. Conclusion: Concentration of MM dispensaries surrounding young adult marijuana users in Los Angeles was unrelated to days of marijuana use irrespective of having a MM recommendation or not. Rather, individual factors related to consumer choices and behaviors were more important in determining recent marijuana use among MMP and NPU.