Faculty Bibliography

BACKGROUND:Violent injuries are a leading cause of morbidity and mortality among youths. Little is known about adolescents' patterns of and risk factors for repeat assault injuries, yet understanding who is at risk for repeated assaults is important for intervention and prevention efforts. Investigating these questions in population-based adolescent samples is particularly critical. OBJECTIVE:Our aim was to estimate the 5-year cumulative incidence of and risk factors for repeat emergency department (ED) visits for assault injury among adolescents experiencing an index assault visit, and compare the method of injury for adolescents' first and second visits. METHODS:Statewide, longitudinal data from California were used to follow 17,845 adolescents who reported to an ED with assault-related injuries in 2010. Incidence rate ratios were estimated to examine risk factors for repeat assault injury within 1 year and 5 years following the index visit. RESULTS:A total of 3273 (18.3%) assaulted adolescents experienced one or more additional assault injury ED visits during the full follow-up period. Only 37.3% of these repeat assaults occurred within the first year following the index assault. Of adolescents with a repeat assault injury, the method of injury often changed and followed no clear pattern. Sociodemographic characteristics (e.g., older age, black race) and history of prior ED visits for assault and mental health problems predicted increased risk of repeat assault. CONCLUSIONS:Previous work may underestimate the rate of repeated assault among adolescents. Adolescents with a history of violence involvement and mental health problems are at elevated risk for repeated assault, and should be targeted for intervention.

AIMS/OBJECTIVE:Amid changing marijuana policies in the Southern Cone, we examined relationships between marijuana-related risk factors and marijuana use among adolescents in Argentina, Chile, and Uruguay from 2001 to 2016. METHODS:graders and weighted time-varying effect models, we estimated associations between perceived risk (no/low risk versus moderate/great risk) and perceived availability (easy/very easy versus difficult/very difficult/not able to obtain) of marijuana, and any past-month marijuana use. RESULTS:In all countries, marijuana use increased over time and adolescents who perceived no/low risk and easy availability had higher odds of use. In Argentina, the bivariate risk/use association weakened from 2001 (OR = 15.24, 95%CI = 9.63, 24.12) to 2004 [OR = 3.86 (2.72, 5.48)] and strengthened until 2011 [OR = 8.22 (7.56, 10.30)]; the availability/use association strengthened from 2005 [OR = 5.32 (4.05, 6.98)] to 2009 [OR = 20.77 (15.57, 27.70)] and weakened until 2014 [OR = 11.00 (9.11, 13.27)]. In Chile, the risk/use association weakened from 2001 [OR = 7.22 (6.57, 7.95)] to 2015 [OR = 5.58 (4.82, 6.48)]; the availability/use association weakened from 2001 [OR = 5.92 (4.96, 7.06)] to 2015 [OR = 4.10 (3.15, 5.34)]. In Uruguay, the risk/use association weakened from 2003 [OR = 34.22 (22.76, 51.46)] to 2016 [OR = 6.23 (4.96, 7.83)]; the availability/use association weakened from 2005 [OR = 29.13 (13.39, 63.39) to 2007 [OR = 9.42 (3.85, 23.07)], and strengthened until 2016 [OR = 22.68 (12.03, 42.76)]. CONCLUSIONS:Overall, the association between risk and use weakened in all countries, suggesting risk perceptions became a weaker determinant of marijuana use. Perceived availability remained strongly associated with use and may become an increasingly important driver of use (particularly in Uruguay and Argentina).

OBJECTIVES/OBJECTIVE:To estimate associations between psychiatric disorders and gun carrying among adolescents and to estimate the total number of adolescents in the US who have psychiatric disorders and report carrying guns. STUDY DESIGN/METHODS:We used cross-sectional data from the National Comorbidity Survey - Adolescent Supplement, a nationally representative sample of adolescents age 13-18 years (N = 10 123; response rate = 75.6%). Psychiatric disorders were assessed using the Composite International Diagnostic Interview. Gun carrying in the 30 days prior to the interview was assessed by self-report. We used multivariable Poisson regression to test for associations. RESULTS:The analytic sample included 10 112 adolescents, 2.4% of whom reported carrying a gun in the prior 30 days. The prevalence of gun carrying was greater among adolescents with conduct disorder (adjusted prevalence ratio [APR] = 1.88, 95% CI 1.38, 2.57), drug use disorders (APR = 1.91, 95% CI 1.05, 3.45), and specific phobias (APR = 1.54, 95% CI 1.07, 2.22) compared with adolescents without these disorders. We estimated that 1.1% (95% CI 0.77, 1.48) of adolescents with a disorder associated with self- or other-directed violence also carry guns. Nationally, that is approximately 272 000 adolescents with both risk factors. CONCLUSIONS:Specific psychiatric disorders are associated with an increased risk of gun carrying among adolescents, but the vast majority of adolescents with psychiatric disorders did not report gun carrying. Targeted efforts to assess access to and use of firearms in mental healthcare and other clinical settings are important, as are efforts to identify population approaches to prevention.

Objectives. To estimate the number of lives saved from firearms suicide with expansions of gun restrictions based on mental health compared with the number who would be unnecessarily restricted. Methods. Agent-based models simulated effects on suicide mortality resulting from 5-year ownership disqualifications in New York City for individuals with any psychiatric hospitalization and, more broadly, anyone receiving psychiatric treatment. Results. Restrictions based on New York State Office of Mental Health-identified psychiatric hospitalizations reduced suicide among those hospitalized by 85.1% (95% credible interval = 36.5%, 100.0%). Disqualifications for anyone receiving psychiatric treatment reduced firearm suicide rates among those affected and in the population; however, 244 820 people were prohibited from firearm ownership who would not have died from firearm suicide even without the policy. Conclusions. In this simulation, denying firearm access to individuals in psychiatric treatment reduces firearm suicide among those groups but largely will not affect population rates. Broad and unfeasible disqualification criteria would needlessly restrict millions at low risk, with potential consequences for civil rights, increased stigma, and discouraged help seeking.

Systems science models use computer-based algorithms to model dynamic interactions between study units within and across levels and are characterized by nonlinear and feedback processes. They are particularly valuable approaches that complement the traditional epidemiologic toolbox in cases in which real data are not available and in cases in which traditional epidemiologic methods are limited by issues such as interference, spatial dependence, and dynamic feedback processes. In this commentary, we propose 2 key contributions that systems models can make to epidemiology: 1) the ability to test assumptions about underlying mechanisms that give rise to population distributions of disease; and 2) help in identifying the types of interventions that have the greatest potential to reduce population rates of disease in the future or in new sites where they have not yet been implemented. We discuss central challenges in the application of systems science approaches in epidemiology, propose potential solutions, and predict future developments in the role that systems science can play in epidemiology.

Increasing alcohol outlet density is well-documented to be associated with increased alcohol use and problems, leading to the policy recommendation that limiting outlet density will decrease alcohol problems. Yet few studies of decreasing problematic outlets and outlet density have been conducted. We estimated the association between closing alcohol outlets and alcohol use and alcohol-related violence, using an agent-based model of the adult population in New York City. The model was calibrated according to the empirical distribution of the parameters across the city's population, including the density of on- and off-premise alcohol outlets. Interventions capped the alcohol outlet distribution at the 90th up to the 50th percentiles of the New York City density, and closed 5% to the 25% of outlets with the highest levels of violence. Capping density led to a lower population of light drinkers (42.2% at baseline vs. 38.1% at the 50th percentile), while heavy drinking increased slightly (12.0% at baseline vs. 12.5% at the 50th percentile). Alcohol-related homicides and non-fatal violence remained unchanged. Closing violent outlets was not associated with changes in alcohol use or related problems. Results suggest that focusing solely on closing alcohol outlets may not be an effective strategy to reduce alcohol-related problems.

INTRODUCTION/BACKGROUND:We sought to understand the association between youthful self-harm and subsequent chronic disease-related healthcare utilization and whether self-harm reflects unique vulnerability in comparison with severe psychiatric disorders. METHODS:We used a retrospective matched cohort design with statewide, all-payer, individually linked emergency department (ED) data from California, USA. Risk of future ED visits for common chronic conditions in adolescence (headaches, asthma, epilepsy, diabetes, and gastrointestinal disorders, assessed using ICD-9 diagnoses) were compared between three adolescent study groups presenting to an ED in 2010: self-harm patients (n = 5,484), patients with psychiatric complaints but no self-harm (n = 14,235), and patients with other complaints (n = 16,452). Cohort follow-up ended on Sept. 30, 2015. Analyses were adjusted for patients' prior histories of ED utilization for chronic conditions as well as patient- and area-level sociodemographic characteristics. RESULTS:Risk of subsequent ED visits was higher among self-harm patients compared to non-psychiatric control patients for subsequent epilepsy- (aRR = 1.77, 95% CI [1.42, 2.21]). Risk of subsequent ED visits was higher among psychiatric patients compared to non-psychiatric control patients for subsequent headache- (aRR = 1.31, 95% CI [1.21, 1.42]), and epilepsy-related problems (aRR = 1.85, 95% CI [1.55, 2.21]). Self-harm patients were at higher risk than psychiatric patients for subsequent gastrointestinal disorder (aRR = 1.76, 95% CI [1.03, 3.01]). CONCLUSIONS:Findings suggest that self-harm behavior and psychiatric disorders are associated with increased ED utilization for subsequent chronic disease-related ED utilization. Chronic disease among adolescent psychiatric patients should be attended to, potentially involving new models of clinical follow-up care.

OBJECTIVE:To determine whether restrictiveness-permissiveness of state gun laws or gun ownership are associated with mass shootings in the US. DESIGN/METHODS:Cross sectional time series. SETTING AND POPULATION/METHODS:US gun owners from 1998-2015. EXPOSURE/METHODS:An annual rating between 0 (completely restrictive) and 100 (completely permissive) for the gun laws of all 50 states taken from a reference guide for gun owners traveling between states from 1998 to 2015. Gun ownership was estimated annually as the percentage of suicides committed with firearms in each state. MAIN OUTCOME MEASURE/METHODS:Mass shootings were defined as independent events in which four or more people were killed by a firearm. Data from the Federal Bureau of Investigation's Uniform Crime Reporting System from 1998-2015 were used to calculate annual rates of mass shootings in each state. Mass shooting events and rates were further separated into those where the victims were immediate family members or partners (domestic) and those where the victims had other relationships with the perpetrator (non-domestic). RESULTS:Fully adjusted regression analyses showed that a 10 unit increase in state gun law permissiveness was associated with a significant 11.5% (95% confidence interval 4.2% to 19.3%, P=0.002) higher rate of mass shootings. A 10% increase in state gun ownership was associated with a significant 35.1% (12.7% to 62.7%, P=0.001) higher rate of mass shootings. Partially adjusted regression analyses produced similar results, as did analyses restricted to domestic and non-domestic mass shootings. CONCLUSIONS:States with more permissive gun laws and greater gun ownership had higher rates of mass shootings, and a growing divide appears to be emerging between restrictive and permissive states.

BACKGROUND:Prescription drug monitoring program are designed to reduce harms from prescription opioids; however, little is known about what populations benefit the most from these programs. We investigated how the relation between implementation of online prescription drug monitoring programs and rates of hospitalizations related to prescription opioids and heroin overdose changed over time, and varied across county levels of poverty and unemployment, and levels of medical access to opioids. METHODS:Ecologic county-level, spatiotemporal study, including 990 counties within 16 states, in 2001-2014. We modeled overdose counts using Bayesian hierarchical Poisson models. We defined medical access to opioids as the county-level rate of hospital discharges for noncancer pain conditions. RESULTS:In 2010-2014, online prescription drug monitoring programs were associated with lower rates of prescription opioid-related hospitalizations (rate ratio 2014 = 0.74; 95% credible interval = 0.69, 0.80). The association between online prescription drug monitoring programs and heroin-related hospitalization was also negative but tended to increase in later years. Counties with lower rates of noncancer pain conditions experienced a lower decrease in prescription opioid overdose and a faster increase in heroin overdoses. No differences were observed across different county levels of poverty and unemployment. CONCLUSIONS:Areas with lower levels of noncancer pain conditions experienced the smallest decrease in prescription opioid overdose and the faster increase in heroin overdose following implementation of online prescription drug monitoring programs. Our results are consistent with the hypothesis that prescription drug monitoring programs are most effective in areas where people are likely to access opioids through medical providers.

BACKGROUND:Medical cannabis laws (MCL) have received increased attention as potential drivers of cannabis use (CU), but little work has explored how the broader policy climate, independent of MCL, may impact CU outcomes. We explored the association between state-level policy liberalism and past-year cannabis use (CU) and cannabis use disorder (CUD). METHODS:We obtained state-level prevalence of past-year CU and CUD among past year cannabis users for ages 12-17, 18-25, and 26+ from the 2004-2006 and 2010-2012 National Surveys on Drug Use and Health. States were categorized as liberal, moderate, or conservative based on state-level policy liberalism rankings in 2005 and 2011. Linear models with random state effects examined the association between policy liberalism and past-year CU and CUD, adjusting for state-level social and economic covariates and medical cannabis laws. RESULTS:In adjusted models, liberal states had higher average past-year CU than conservative states for ages 12-17 (+1.58 percentage points; p = 0.03) and 18-25 (+2.96 percentage points; p = 0.01) but not for 26+ (p = 0.19). CUD prevalence among past year users was significantly lower in liberal compared to conservative states for ages 12-17 (-2.87 percentage points; p = 0.045) and marginally lower for ages 26+ (-2.45 percentage points; p = 0.05). CONCLUSION/CONCLUSIONS:Liberal states had higher past-year CU, but lower CUD prevalence among users, compared to conservative states. Researchers and policy makers should consider how the broader policy environment, independent of MCL, may contribute to CU outcomes.