Validation of secondary data sources for enumerating marijuana dispensaries in a state commercializing marijuana.
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ABSTRACT: Objectives
To assess 1) the validity of online crowdsourcing platforms in enumerating licensed brick-and-mortar marijuana dispensaries and 2) the validity of state licensing directory and online crowdsourcing platforms in enumerating active brick-and-mortar marijuana dispensaries in California.Methods
We obtained business lists from California Bureau of Cannabis Control (BCC) licensing directory and three online crowdsourcing platforms (Weedmaps, Leafly, and Yelp) in May 2019. Calls were made to verify street address, operation status, dispensary category (recreational-only, medical-only, recreational & medical), and presence of storefronts in May-July 2019. Validity measures, including sensitivity, specificity, positive predictive value, and negative predictive value, were calculated when applicable.Results
In identifying licensed dispensaries in BCC, Leafly had the highest sensitivity (.66) and Yelp had the highest specificity (.87). The dispensary category posted on online crowdsourcing platforms in over 25 % licensed dispensaries and the dispensary category claimed in call verification in over 10 % licensed dispensaries disagreed with the approved category in BCC. There were 2121 businesses combined from BCC and online crowdsourcing platforms, among which 826 were verified to be active brick-and-mortar dispensaries. Weedmaps had the highest sensitivity (.80) and Yelp had the highest negative predictive value (.74) in identifying verified dispensaries. Weedmaps overall had the highest sensitivity in all three dispensary categories. Weedmaps had the highest sensitivity in more populated counties whereas BCC had the highest sensitivity in less populated counties.Conclusions
Each secondary data source has strengths and limitations. The findings inform surveillance and research regarding how to best strategize data use when resources are limited.
SUBMITTER: Cao Y
PROVIDER: S-EPMC7502490 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description: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.
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| S-EPMC3551728 | biostudies-literature
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| S-EPMC6930340 | biostudies-literature
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| S-EPMC4312428 | biostudies-other
Project description:BackgroundValidation studies of secondary datasets used to characterize neighborhood food businesses generally evaluate how accurately the database represents the true situation on the ground. Depending on the research objectives, the characterization of the business environment may tolerate some inaccuracies (e.g. minor imprecisions in location or errors in business names). Furthermore, if the number of false negatives (FNs) and false positives (FPs) is balanced within a given area, one could argue that the database still provides a "fair" representation of existing resources in this area. Yet, traditional validation measures do not relax matching criteria, and treat FNs and FPs independently. Through the field validation of food businesses found in a Canadian database, this paper proposes alternative criteria for validity.MethodsField validation of the 2010 Enhanced Points of Interest (EPOI) database (DMTI Spatial®) was performed in 2011 in 12 census tracts (CTs) in Montreal, Canada. Some 410 food outlets were extracted from the database and 484 were observed in the field. First, traditional measures of sensitivity and positive predictive value (PPV) accounting for every single mismatch between the field and the database were computed. Second, relaxed measures of sensitivity and PPV that tolerate mismatches in business names or slight imprecisions in location were assessed. A novel measure of representativity that further allows for compensation between FNs and FPs within the same business category and area was proposed. Representativity was computed at CT level as ((TPs +|FPs-FNs|)/(TPs+FNs)), with TPs meaning true positives, and |FPs-FNs| being the absolute value of the difference between the number of FNs and the number of FPs within each outlet category.ResultsThe EPOI database had a "moderate" capacity to detect an outlet present in the field (sensitivity: 54.5%) or to list only the outlets that actually existed in the field (PPV: 64.4%). Relaxed measures of sensitivity and PPV were respectively 65.5% and 77.3%. The representativity of the EPOI database was 77.7%.ConclusionsThe novel measure of representativity might serve as an alternative to traditional validity measures, and could be more appropriate in certain situations, depending on the nature and scale of the research question.
| S-EPMC3710283 | biostudies-literature
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Project description:Venue-based distribution of marijuana has become the normative model in the United States to obtain marijuana. This study examines one-time purchase behaviors at medical marijuana dispensaries (MMDs) to identify potential venue- and individual-level targets for prevention. We used a two-stage, venue-based sampling approach to randomly select patrons exiting 16 MMDs in Los Angeles, California during the spring of 2013. Patrons (N?=?595) reported their discrete purchase behaviors during their most recent visit to the sampled MMD. We used hierarchical linear modeling to examine the amount spent on marijuana products, regressed on characteristics of the sampled dispensaries and their patrons. We used hierarchical generalized linear modeling to examine the likelihood of purchasing specific types of marijuana products and total grams of loose-leaf buds purchased. Patrons spent US$41.73 on average, with a range of $0-$330. We observed significant variation in purchase behaviors across MMDs and associations between venues located within high median income census tracts and a higher total amount spent and lower odds of purchasing only loose-leaf buds. The networked distance between a patron's home and the sampled MMD was positively associated with the total amount spent and total quantity of buds purchased. We also found significant relationships between medical conditions reported for use in three models: total amount spent, purchase of pre-rolled joints, and total grams of buds purchased. Policy makers may want to explore regulating the availability of specialty items that may be attractive to naïve users, such as pre-rolled joints or edibles, or high-concentration products that may be sought out by regular, heavy users.
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Project description:ImportanceHistorical shifts are occurring in marijuana policy. The effect of legalizing marijuana for recreational use on rates of adolescent marijuana use is a topic of considerable debate.ObjectiveTo examine the association between the legalization of recreational marijuana use in Washington and Colorado in 2012 and the subsequent perceived harmfulness and use of marijuana by adolescents.Design, setting, and participantsWe used data of 253 902 students in eighth, 10th, and 12th grades from 2010 to 2015 from Monitoring the Future, a national, annual, cross-sectional survey of students in secondary schools in the contiguous United States. Difference-in-difference estimates compared changes in perceived harmfulness of marijuana use and in past-month marijuana use in Washington and Colorado prior to recreational marijuana legalization (2010-2012) with postlegalization (2013-2015) vs the contemporaneous trends in other states that did not legalize recreational marijuana use in this period.Main outcomes and measuresPerceived harmfulness of marijuana use (great or moderate risk to health from smoking marijuana occasionally) and marijuana use (past 30 days).ResultsOf the 253 902 participants, 120 590 of 245 065(49.2%) were male, and the mean (SD) age was 15.6 (1.7) years. In Washington, perceived harmfulness declined 14.2% and 16.1% among eighth and 10th graders, respectively, while marijuana use increased 2.0% and 4.1% from 2010-2012 to 2013-2015. In contrast, among states that did not legalize recreational marijuana use, perceived harmfulness decreased by 4.9% and 7.2% among eighth and 10th graders, respectively, and marijuana use decreased by 1.3% and 0.9% over the same period. Difference-in-difference estimates comparing Washington vs states that did not legalize recreational drug use indicated that these differences were significant for perceived harmfulness (eighth graders: % [SD], -9.3 [3.5]; P = .01; 10th graders: % [SD], -9.0 [3.8]; P = .02) and marijuana use (eighth graders: % [SD], 5.0 [1.9]; P = .03; 10th graders: % [SD], 3.2 [1.5]; P = .007). No significant differences were found in perceived harmfulness or marijuana use among 12th graders in Washington or for any of the 3 grades in Colorado.Conclusions and relevanceAmong eighth and 10th graders in Washington, perceived harmfulness of marijuana use decreased and marijuana use increased following legalization of recreational marijuana use. In contrast, Colorado did not exhibit any differential change in perceived harmfulness or past-month adolescent marijuana use following legalization. A cautious interpretation of the findings suggests investment in evidence-based adolescent substance use prevention programs in any additional states that may legalize recreational marijuana use.
| S-EPMC5365078 | biostudies-literature
Project description:BackgroundLittle is known on how perceived availability of marijuana is associated with medical marijuana laws. We examined the relationship between medical marijuana laws (MML) and the prevalence of past-month marijuana use, with perceived availability of marijuana.MethodsData were from respondents included in the National Survey of Drug Use and Health restricted use data portal 2004-2013. Multilevel logistic regression of individual-level data was used to test differences between MML and non-MML states and changes in prevalence of past-month marijuana use and perceived availability from before to after passage of MML among adolescents, young adults and older adults controlling for demographics.ResultsAmong adults 26+, past-month prevalence of marijuana use increased from 5.87% to 7.15% after MML passage (Adjusted Odds Ratio (AOR): 1.24 [1.16-1.31]), but no change in prevalence of use was found for 12-17 or 18-25 year-olds. Perceived availability of marijuana increased after MML was enacted among those 26+ but not in younger groups. Among all age groups, prevalence of marijuana use and perception of it being easily available was higher in states that would eventually pass MML by 2013 compared to those that had not. Perceived availability was significantly associated with increased risk of past-month marijuana use in all age groups.ConclusionEvidence suggests perceived availability as a driver of change in use of marijuana due to MML. To date, this has only occurred in adults 26+ and different scenarios that could explain this change need to be further explored.
| S-EPMC5140747 | biostudies-literature
Project description:AimsTo test, among US students: (1) whether perceived harmfulness of marijuana has changed over time, (2) whether perceived harmfulness of marijuana changed post-passage of state medical marijuana laws (MML) compared with pre-passage; and (3) whether perceived harmfulness of marijuana statistically mediates and/or modifies the relation between MML and marijuana use as a function of grade level.DesignCross-sectional nationally representative surveys of US students, conducted annually, 1991-2014, in the Monitoring the Future study.SettingSurveys conducted in schools in all coterminous states; 21 states passed MML between 1996 and 2014.ParticipantsThe sample included 1 134 734 adolescents in 8th, 10th and 12th grades.MeasurementsState passage of MML; perceived harmfulness of marijuana use (perceiving great or moderate risk to health from smoking marijuana occasionally versus slight or no risk); and marijuana use (prior 30 days). Data were analyzed using time-varying multi-level regression modeling.FindingsThe perceived harmfulness of marijuana has decreased significantly since 1991 (from an estimated 84.0% in 1991 to 53.8% in 2014, P < 0.01) and, across time, perceived harmfulness was lower in states that passed MML [odds ratio (OR) = 0.86, 95% confidence interval (CI) = 0.75-0.97]. In states with MML, perceived harmfulness of marijuana increased among 8th graders after MML passage (OR = 1.21, 95% CI = 1.08-1.36), while marijuana use decreased (OR = 0.81, 95% CI = 0.72-0.92). Results were null for other grades, and for all grades combined. Increases in perceived harmfulness among 8th graders after MML passage was associated with ~33% of the decrease in use. When adolescents were stratified by perceived harmfulness, use in 8th graders decreased to a greater extent among those who perceived marijuana as harmful.ConclusionsWhile perceived harmfulness of marijuana use appears to be decreasing nationally among adolescents in the United States, the passage of medical marijuana laws (MML) is associated with increases in perceived harmfulness among young adolescents and marijuana use has decreased among those who perceive marijuana to be harmful after passage of MML.
| S-EPMC5222836 | biostudies-literature