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

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. Examine the relationship between density of MM dispensaries and frequency of marijuana use among young adult medical marijuana patients (MMP) and nonpatient users (NPU). Young adult marijuana users ( = 329) aged 18- to 26-year old were sampled in Los Angeles in 2014-2015 and separated into MMP ( = 198) and NPU ( = 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. 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. 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.