Faculty Bibliography

INTRODUCTION AND AIMS/OBJECTIVE:Given a scenario of intense discussion about the legal situation of cannabis users worldwide, this paper aims to investigate the role of cannabis within a drug use sequencing pattern. DESIGN AND METHODS/METHODS:Data came from a representative sample of college students from 27 Brazilian capitals (n = 12 711). We analysed the patterns of transition from/to the first use of cannabis to/from the first use of alcohol, tobacco and seven other illegal drugs. Survival analysis methods were used to analyse age of onset data on all potential drug pairs. Drugs that were not specified as the target drug pair tested in each survival model were included as time-varying covariates in all models. RESULTS:We found significant transitions from alcohol [adjusted hazard ratio (aHR) = 1.41, 95% confidence interval (CI) 1.15-1.73, P < 0.001] and inhalants (aHR = 1.56, 95% CI 1.26-1.93, P < 0.001) to cannabis. Moreover, we found significant transitions from cannabis to alcohol (aHR = 2.40, 95% CI 1.47-3.91, P < 0.001), cocaine (aHR = 7.47, 95% CI = 4.26-13.09, P < 0.001), prescription opioids (aHR = 2.16, 95% CI 1.29-3.63, P < 0.01) and tranquilisers (aHR = 1.51, 95% CI 1.11-2.06, P < 0.01). DISCUSSION AND CONCLUSIONS/CONCLUSIONS:Overall, our findings point to a strategic role of cannabis within drug first use sequence pattern. We had an important and unexpected finding-the bi-directional relationship between alcohol and cannabis. In addition, the first use of cannabis still precedes the first use of cocaine and non-medical use of tranquilisers and prescription opioids. [Castaldelli-Maia JM, Nicastri S, Cerdá M, Kim JH, Oliveira LG, Andrade AG, Martins, SS. In-transition culture of experimentation with cannabis in Latin American college students: A new role within a potential drug use sequencing pattern. Drug Alcohol Rev 2017;00:000-000].

BACKGROUND:Cities are investing millions in Cure Violence, a public health approach to reduce urban violence by targeting at-risk youth and redirecting conflict to nonviolent responses. The impact of such a program compared with criminal justice responses is unknown because experiments directly comparing criminal justice and public health approaches to violence prevention are infeasible with observational data. We simulated experiments to test the influence of two interventions on violence: (1) Cure Violence and (2) directed police patrol in violence hot spots. METHODS:We used an agent-based model to simulate a 5% sample of the New York City (NYC) adult population, with agents placed on a grid representing the land area of NYC, with neighborhood size and population density proportional to land area and population density in each community district. Agent behaviors were governed by parameters drawn from city data sources and published estimates. RESULTS:Under no intervention, 3.87% (95% CI, 3.84, 3.90) of agents were victimized per year. Implementing the violence interrupter intervention for 10 years decreased victimization by 13% (to 3.35% [3.32, 3.39]). Implementing hot-spots policing and doubling the police force for 10 years reduced annual victimization by about 11% (to 3.46% [3.42, 3.49]). Increasing the police force by 40% combined with implementing the violence interrupter intervention for 10 years decreased violence by 19% (to 3.13% [3.09, 3.16]). CONCLUSIONS:Combined investment in a public health, community-based approach to violence prevention and a criminal justice approach focused on deterrence can achieve more to reduce population-level rates of urban violence than either can in isolation. See video abstract at, http://links.lww.com/EDE/B298.

BACKGROUND:Comprehensive background check (CBC) policies are hypothesised to reduce firearm-related violence because they extend background checks to private party firearm sales, but no study has determined whether these policies actually increase background checks, an expected intermediary outcome. We evaluate the association between CBC policies and the rates of firearm background checks in three states that recently implemented these policies: Delaware (July 2013), Colorado (July 2013) and Washington (December 2014). METHODS:We used the synthetic control group method to estimate the difference from estimated counterfactual postintervention trends in the monthly rate of background checks per 1 00 000 people for handguns, long guns and both types combined, using data for January 1999 through December 2016. Inference was based on results from permutation tests. We conducted multiple sensitivity analyses to assess the robustness of our results. RESULTS:Background check rates increased in Delaware, by 22%-34% depending on the type of firearm, following enactment of its CBC law. No overall changes were observed in Washington and Colorado. Our results were robust to changes in the comparison group and statistical methods. CONCLUSIONS:The enactment of CBC policies was associated with an overall increase in firearm background checks only in Delaware. Data external to the study suggest that Washington experienced a modest, but consistent, increase in background checks for private party sales, and Colorado experienced a similar increase in checks for sales not at gun shows. Non-compliance may explain the lack of an overall increase in background checks in Washington and Colorado.

BACKGROUND:Historical shifts have taken place in the last twenty years in marijuana policy. The impact of medical marijuana laws (MML) on use of substances other than marijuana is not well understood. We examined the relationship between state MML and use of marijuana, cigarettes, illicit drugs, nonmedical use of prescription opioids, amphetamines, and tranquilizers, as well as binge drinking. METHODS:Pre-post MML difference-in-difference analyses were performed on a nationally representative sample of adolescents in 48 contiguous U.S. states. Participants were 1,179,372U.S. 8th, 10th, and 12th graders in the national Monitoring the Future annual surveys conducted in 1991-2015. Measurements were any self-reported past-30-day use of marijuana, cigarettes, non-medical use of opioids, amphetamines and tranquilizers, other illicit substances, and any past-two-week binge drinking (5+ drinks per occasion). RESULTS:Among 8th graders, the prevalence of marijuana, binge drinking, cigarette use, non-medical use of opioids, amphetamines and tranquilizers, and any non-marijuana illicit drug use decreased after MML enactment (0.2-2.4% decrease; p-values:<0.0001-0.0293). Among 10th graders, the prevalence of substance use did not change after MML enactment (p-values: 0.177-0.938). Among 12th graders, non-medical prescription opioid and cigarette use increased after MML enactment (0.9-2.7% increase; p-values: <0.0001-0.0026). CONCLUSIONS:MML enactment is associated with decreases in marijuana and other drugs in early adolescence in those states. Mechanisms that explain the increase in non-medical prescription opioid and cigarette use among 12th graders following MML enactment deserve further study.

Agent-based modeling is a computational approach in which agents with a specified set of characteristics interact with each other and with their environment according to predefined rules. We review key areas in public health where agent-based modeling has been adopted, including both communicable and noncommunicable disease, health behaviors, and social epidemiology. We also describe the main strengths and limitations of this approach for questions with public health relevance. Finally, we describe both methodologic and substantive future directions that we believe will enhance the value of agent-based modeling for public health. In particular, advances in model validation, comparisons with other causal modeling procedures, and the expansion of the models to consider comorbidity and joint influences more systematically will improve the utility of this approach to inform public health research, practice, and policy.

AIMS/OBJECTIVE:To conduct a systematic review and meta-analysis of studies in order to estimate the effect of US medical marijuana laws (MMLs) on past-month marijuana use prevalence among adolescents. METHODS:A total of 2999 papers from 17 literature sources were screened systematically. Eleven studies, developed from four ongoing large national surveys, were meta-analyzed. Estimates of MML effects on any past-month marijuana use prevalence from included studies were obtained from comparisons of pre-post MML changes in MML states to changes in non-MML states over comparable time-periods. These estimates were standardized and entered into a meta-analysis model with fixed-effects for each study. Heterogeneity among the study estimates by national data survey was tested with an omnibus F-test. Estimates of effects on additional marijuana outcomes, of MML provisions (e.g. dispensaries) and among demographic subgroups were abstracted and summarized. Key methodological and modeling characteristics were also described. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. RESULTS:None of the 11 studies found significant estimates of pre-post MML changes compared with contemporaneous changes in non-MML states for marijuana use prevalence among adolescents. The meta-analysis yielded a non-significant pooled estimate (standardized mean difference) of -0.003 (95% confidence interval = -0.012, +0.007). Four studies compared MML with non-MML states on pre-MML differences and all found higher rates of past-month marijuana use in MML states pre-MML passage. Additional tests of specific MML provisions, of MML effects on additional marijuana outcomes and among subgroups generally yielded non-significant results, although limited heterogeneity may warrant further study. CONCLUSIONS:Synthesis of the current evidence does not support the hypothesis that US medical marijuana laws (MMLs) until 2014 have led to increases in adolescent marijuana use prevalence. Limited heterogeneity exists among estimates of effects of MMLs on other patterns of marijuana use, of effects within particular population subgroups and of effects of specific MML provisions.

BACKGROUND:Self-medication with drugs or alcohol is commonly reported among adults with mood or anxiety disorders, and increases the risk of developing substance use disorders. Medical marijuana laws (MML) may be associated with greater acceptance of the therapeutic value of marijuana, leading individuals to self-medicate. METHODS:The study utilized data from Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (2004-2005). Participants were sampled from households in the general population and included adults with a mood or anxiety disorder in the past 12 months (n = 7418), and the subset of those who used marijuana and no other drug (n = 314). Weighted logistic regression models predicted the prevalence of self-medication with drugs in U.S. states with and without MML, adjusting for individual and state-level covariates. As a negative control, analyses were repeated for self-medication with alcohol. RESULTS:Overall, self-medication with drugs was 3.73 percentage points higher (95% confidence interval [CI]: 0.93-6.53) among those living in MML states (p = 0.01). For the subpopulation that only used marijuana, self-medication with drugs was 21.22 percentage points higher (95% CI: 3.91-38.53) among those living in MML states (p = 0.02). In contrast, self-medication with alcohol had nearly identical prevalence in MML and non-MML states, overall and for drinkers. CONCLUSIONS:Among adults with mood or anxiety disorders, living in a medical marijuana law state is associated with self-medication with marijuana. While additional research is needed to determine the reasons for this association, clinical screening for self-medication with marijuana may be particularly important in states with medical marijuana laws.

BACKGROUND:National trends in adolescent's marijuana risk perceptions are traditionally used as a predictor of concurrent and future trends in adolescent marijuana use. We test the validity of this practice during a time of rapid marijuana policy change. METHODS:Two repeated cross-sectional U.S. nationally-representative surveys of 8th, 10th, and 12th-graders: Monitoring the Future (MTF) (1991-2015; N = 1,181,692) and National Survey on Drug Use and Health (NSDUH) (2002-2014; N = 113,317). We examined trends in the year-to-year prevalence of perceiving no risk of harm in using marijuana regularly, and prevalence of regular marijuana use within the previous month. A piecewise linear regression model tested for a change in the relationship between trends. Similar analyses examined any past-month use and controlled for demographic characteristics. RESULTS:Among MTF 12th-graders, the prevalence of regular marijuana use and risk perceptions changed similarly between 1991 and 2006 but diverged sharply afterward. The prevalence of regular marijuana use increased by ∼1 percentage point to 6.03% by 2015. In contrast, the proportion of 12th-graders that perceived marijuana as posing no risk increased over 11 percentage points to 21.39%. A similar divergence was found among NSDUH 12th-graders and other grades, for any past month marijuana use, and when controlling demographic characteristics. CONCLUSIONS:An increase in adolescent marijuana use has not accompanied recent rapid decreases in marijuana risk perceptions. Policy makers may consider broader prevention strategies in addition to targeting marijuana risk perceptions. Further monitoring of predictors of marijuana use trends is needed as states legalize recreational marijuana use.

BACKGROUND:In 2016, firearms killed 38,658 people in the United States. Federal law requires licensed gun dealers, but not private parties, to conduct background checks on prospective firearm purchasers with the goal of preventing prohibited persons from obtaining firearms. Our objective was to estimate the effect of the repeal of comprehensive background check laws - requiring a background check for all handgun sales, not just sales by licensed dealers - on firearm homicide and suicide rates in Indiana and Tennessee. METHODS:We compared age-adjusted firearm homicide and suicide rates, measured annually from 1981-2008 and 1994-2008 in Indiana and Tennessee, respectively, to rates in control groups constructed using the synthetic control method. RESULTS:The average rates of firearm homicide and suicide in Indiana and Tennessee following repeal were within the range of what could be expected given natural variation (differences = 0.7 firearm homicides and 0.5 firearm suicides per 100,000 residents in Indiana and 0.4 firearm homicides and 0.3 firearm suicides per 100,000 residents in Tennessee). Sensitivity analyses resulted in similar findings. CONCLUSION/CONCLUSIONS:We found no evidence of an association between the repeal of comprehensive background check policies and firearm homicide and suicide rates in Indiana and Tennessee. In order to understand whether comprehensive background check policies reduce firearm deaths in the United States generally, more evidence on the impact of such policies from other states is needed.

PURPOSE/OBJECTIVE:Firearm mortality is a significant problem in the United States. Previous studies have largely focused on firearm mortality at the national or state level, leaving open the question of within-state variation. This study examined firearm mortality within California. METHODS:We used Multiple Cause of Death data files to identify all firearm fatalities in California from 2000 to 2015. We described firearm mortality rates and counts over time, by age and county, stratifying by intent, gender, and race/ethnicity. County-level rates were smoothed with empirical Bayes estimates from random-effect Poisson models. RESULTS:From 2000 to 2015, there were 24,922 firearm homicides and 23,682 firearm suicides in California. Rates of firearm homicide decreased 30% and suicide rates increased 1% since the mid-2000s, but these trends varied substantially by county. Due to a decline in firearm homicides in metropolitan areas, there was no significant difference in these rates between urban and rural counties by 2015. Non-Hispanic black men had the highest rate of firearm homicide, but Hispanic men had the greatest number of deaths. CONCLUSIONS:We found considerable intrastate variation in firearm mortality in California. Our results will be of interest to researchers, policymakers, and public health practitioners. Similar epidemiologic profiles of firearm mortality are warranted for other states.