Navigating non-positivity in neighbourhood studies: an analysis of collective efficacy and violence

Lower Perceived Neighborhood Collective Efficacy Indirectly Influences the Association Between Perceived Maternal Exposure to Community Violence and Household Food Insecurity

BACKGROUND AND OBJECTIVES

Individuals of color and of low socioeconomic status are at greater risk of experiencing community violence and food insecurity, which are both influenced by neighborhood conditions. We evaluated neighborhood collective efficacy as a linkage between community violence exposure and household food insecurity.

METHODS

Mothers from the Future of Families and Child Wellbeing Study who completed phone surveys when the child was 3 (time 1, T1) and 5 years old (time 2, T2) were included (n = 2068). A covariate-adjusted structural equation model estimated direct and indirect effects of community violence exposure on household food insecurity. A covariate-adjusted multiple mediator model estimated the indirect effects of the 2 neighborhood collective efficacy subscales (informal social control; social cohesion and trust).

RESULTS

At T1, 40% of mothers reported community violence exposure; 15% experienced food insecurity at T2. Mean neighborhood collective efficacy (range 1-5) at T1 was 2.44 (SD = 0.94). Neighborhood collective efficacy indirectly influenced the association between community violence exposure and food insecurity (indirect effect = 0.022, 95% CI = 0.007 to 0.040). Only social cohesion and trust contributed independent variance to the indirect effect model (indirect effect = 0.028, 95% CI = 0.001 to 0.056).

CONCLUSIONS

Community-based efforts to reduce household food insecurity should emphasize building social cohesion and trust in communities experiencing violence.

Age and sex differences in the association between neighborhood socioeconomic environment and incident diabetes: Results from the diabetes location, environmental attributes and disparities (LEAD) network

Objective

Worse neighborhood socioeconomic environment (NSEE) may contribute to an increased risk of type 2 diabetes (T2D). We examined whether the relationship between NSEE and T2D differs by sex and age in three study populations.

Research design and methods

We conducted a harmonized analysis using data from three independent longitudinal study samples in the US: 1) the Veteran Administration Diabetes Risk (VADR) cohort, 2) the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort, and 3) a case-control study of Geisinger electronic health records in Pennsylvania. We measured NSEE with a z-score sum of six census tract indicators within strata of community type (higher density urban, lower density urban, suburban/small town, and rural). Community type-stratified models evaluated the likelihood of new diagnoses of T2D in each study sample using restricted cubic splines and quartiles of NSEE.

Results

Across study samples, worse NSEE was associated with higher risk of T2D. We observed significant effect modification by sex and age, though evidence of effect modification varied by site and community type. Largely, stronger associations between worse NSEE and diabetes risk were found among women relative to men and among those less than age 45 in the VADR cohort. Similar modification by age group results were observed in the Geisinger sample in small town/suburban communities only and similar modification by sex was observed in REGARDS in lower density urban communities.

Conclusions

The impact of NSEE on T2D risk may differ for males and females and by age group within different community types.

Traveling Together: A Road Map for Researching Neighborhood Effects on Population Health and Health Inequities

As evidence of the relationship between place and health mounts, more epidemiologists and clinical science researchers are becoming interested in incorporating place-based measures and analyses into their examination of population health and health inequities. Given the extensive literature on place and health, it can be challenging for researchers new to this area to develop neighborhood-effects research questions and apply the appropriate measures and methods. This paper provides a road map for guiding health researchers through the conceptual and methodological stages of incorporating various dimensions of place into their quantitative health research. Synthesizing across reviews, commentaries, and empirical investigations, the road map consists of 4 broad stages for considering place and health: 1) why?: articulating the motivation for assessing place and health and grounding the motivation in theory; 2) what?: identifying the relevant place-based characteristics and specifying their link to health to build a conceptual framework; 3) how?: determining how to operationalize the conceptual framework by defining, measuring, and assessing place-based characteristics and quantifying their effect on health; and 4) now what?: discussing the implications of neighborhood research findings for future research, policy, and practice. This road map supports efforts to develop conceptually and analytically rigorous neighborhood research projects.

Protection of gender health and fight against gender violence during the COVID-19 pandemic: the experience of our street clinic in a disadvantaged suburb of Rome Metropolitan City

OBJECT

In this study, we evaluated health, social inequalities and risk to gender violence of women living in a disadvantaged degraded suburb of Rome Metropolitan City, during COVID-19 pandemic.

METHODS

The study included 779 women referring to primary care services of Medicina Solidale Institute for gynecological/breast examinations (209), medical and support aid for the children (383) and COVID-19 test execution (187).

RESULTS

The data show that most women (68%) were unemployed or had an irregular job. The request of support varied depending on the ethnicity: while healthcare support was requested mostly by African female community, the COVID-19 test, mandatory for public transportation and work, was a need of the east-european community. Both these communities referred to Medical Solidale primary care service for the healthcare and food/clothing support for their children. It is interesting to note that the requests from the Italian women community was elevated in terms of personal healthcare, support for the children and COVID-19 test execution. The access to the national health system (NHS) resulted a complex administrative procedure despite the original social-ethnic communities. The vast majority of women lacked awareness of their crucial role for supporting the family entity, while inadequacy was commonly reported.

CONCLUSIONS

This study confirms a critical condition for women living in disadvantaged neighborhoods, whose vulnerability is further worsened by the limited access to primary care assistance with serious consequences for health and quality of life. Prevention and treatment, especially for the most vulnerable subjects, should be a priority for the public health system.

Propensity Scores in Health Disparities Research: The Example of Cognitive Aging and the Hispanic Paradox

BACKGROUND

Individuals of Mexican ancestry in the United States experience substantial socioeconomic disadvantages compared with non-Hispanic white individuals; however, some studies show these groups have similar dementia risk. Evaluating whether migration selection factors (e.g., education) associated with risk of Alzheimer disease and related dementia (ADRD) explain this paradoxical finding presents statistical challenges. Intercorrelation of risk factors, common with social determinants, could make certain covariate patterns very likely or unlikely to occur for particular groups, which complicates their comparison. Propensity score (PS) methods could be leveraged here to diagnose nonoverlap and help balance exposure groups.

METHODS

We compare conventional and PS-based methods to examine differences in cognitive trajectories between foreign-born Mexican American, US-born Mexican American, and US-born non-Hispanic white individuals in the Health and Retirement Study (1994-2018). We examined cognition using a global measure. We estimated trajectories of cognitive decline from linear mixed models adjusted for migration selection factors also associated with ADRD risk conventionally or with inverse probability weighting. We also employed PS trimming and match weighting.

RESULTS

In the full sample, where PS overlap was poor, unadjusted analyses showed both Mexican ancestry groups had worse baseline cognitive scores but similar or slower rates of decline compared with non-Hispanic white adults; adjusted findings were similar, regardless of method. Focusing analyses on populations where PS overlap was improved (PS trimming and match weighting) did not alter conclusions.

CONCLUSIONS

Attempting to equalize groups on migration selection and ADRD risk factors did not explain paradoxical findings for Mexican ancestry groups in our study.

Complaints about excessive use of police force in women's neighborhoods and subsequent perinatal and cardiovascular health

There are substantial, unexplained racial disparities in women’s health. Some of the most pronounced involve elevated rates of preterm delivery (PTD) and cardiovascular disease (CVD) among Black women. We hypothesized that stress associated with excessive use of force by police may contribute to these disparities. In two prospective cohorts derived from electronic health records (pregnancy cohort, N = 67,976; CVD cohort, N = 6773), we linked formal complaints of excessive police force in patients’ neighborhoods with health outcomes. Exposed Black women were 1.19 times as likely to experience PTD [95% confidence interval (CI): 1.04 to 1.35] and 1.42 times as likely to develop CVD (95% CI: 1.12 to 1.79), even after adjustment for neighborhood disadvantage and homicide. The excess risks of PTD were also observed in maternal fixed-effects analyses comparing births to the same woman. These findings suggest police violence may be an unrecognized contributor to health inequity for Black women.

Categorizing community type for epidemiologic evaluation of community factors and chronic disease across the United States

Existing classifications of community type do not differentiate urban cores from surrounding non-rural areas, an important distinction for analyses of community features and their impact on health. Inappropriately classified community types can introduce serious methodologic flaws in epidemiologic studies and invalid inferences from findings. To address this, we evaluate a modification of the United States Department of Agriculture's Rural Urban Commuting Area codes at the census tract, propose a four-level categorization of community type, and compare this with existing classifications for epidemiologic analyses. Compared to existing classifications, our method resulted in clearer geographic delineations of community types within urban areas.

What to Do When Everything Happens at Once: Analytic Approaches to Estimate the Health Effects of Co-Occurring Social Policies

Social policies have great potential to improve population health and reduce health disparities. Increasingly, those doing empirical research have sought to quantify the health effects of social policies by exploiting variation in the timing of policy changes across places. Multiple social policies are often adopted simultaneously or in close succession in the same locations, creating co-occurrence that must be handled analytically for valid inferences. Although this is a substantial methodological challenge for researchers aiming to isolate social policy effects, only in a limited number of studies have researchers systematically considered analytic solutions within a causal framework or assessed whether these solutions are being adopted. We designated 7 analytic solutions to policy co-occurrence, including efforts to disentangle individual policy effects and efforts to estimate the combined effects of co-occurring policies. We used an existing systematic review of social policies and health to evaluate how often policy co-occurrence is identified as a threat to validity and how often each analytic solution is applied in practice. Of the 55 studies, only in 17 (31%) did authors report checking for any co-occurring policies, although in 36 studies (67%), at least 1 approach was used that helps address policy co-occurrence. The most common approaches were adjusting for measures of co-occurring policies; defining the outcome on subpopulations likely to be affected by the policy of interest (but not other co-occurring policies); and selecting a less-correlated measure of policy exposure. As health research increasingly focuses on policy changes, we must systematically assess policy co-occurrence and apply analytic solutions to strengthen studies on the health effects of social policies.

Expanding Collective Efficacy Theory to Reduce Violence Among African American Adolescents

Community violence is a complex phenomenon, and many theories have been put forth to explain the causes of community violence and disparities in community violence across neighborhoods. One notable theory, collective efficacy theory (CET), posits that collective efficacy (i.e., a neighborhood's social cohesion and informal social control) mediates the association between concentrated disadvantage and community violence. As CET theorizes an inverse feedback loop between collective efficacy and community violence, collective efficacy could mitigate the link between neighborhood disadvantage and community violence. The current study examines the reciprocal association between collective efficacy and community violence exposure using data from 604 low-resourced, urban African American ninth-grade students from a large Midwestern city. Data were collected at 6-month intervals over 2 years. Significant cross-sectional associations were found between each of the collective efficacy constructs (social cohesion and informal social control) and community violence exposure, although no significant longitudinal cross-lagged associations were found. There were positive cross-sectional associations between (a) collective efficacy and community violence exposure and (b) informal social control and community violence exposure; however, the association between social cohesion and community violence exposure was negative. Associations between overall collective efficacy, as well as its subscales, and community violence exposure were consistent with hypothesized directions for social cohesion, but not for collective efficacy or informal social control. Findings support the use of collective efficacy as two constructs, rather than a single construct as proposed by Sampson et al. Implications for expanding original assumptions of CET are discussed.

Proximity to freshwater blue space and type 2 diabetes onset: the importance of historical and economic context

Salutogenic effects of living near aquatic areas (blue space) remain underexplored, particularly in non-coastal and non-urban areas. We evaluated associations of residential proximity to inland freshwater blue space with new onset type 2 diabetes (T2D) in central and northeast Pennsylvania, USA, using medical records to conduct a nested case-control study. T2D cases (n=15,888) were identified from diabetes diagnoses, medication orders, and laboratory test results and frequency-matched on age, sex, and encounter year to diabetes-free controls (n=79,435). We calculated distance from individual residences to the nearest lake, river, tributary, or large stream, and residence within the 100-year floodplain. Logistic regression models adjusted for community socioeconomic deprivation and other confounding variables and stratified by community type (townships [rural/suburban], boroughs [small towns], city census tracts). Compared to individuals living ≥1.25 miles from blue space, those within 0.25 miles had 8% and 17% higher odds of T2D onset in townships and boroughs, respectively. Among city residents, T2D odds were 38-39% higher for those living 0.25 to <0.75 miles from blue space. Residing within the floodplain was associated with 16% and 14% higher T2D odds in townships and boroughs. A post-hoc analysis demonstrated patterns of lower residential property values with nearer distance to the region's predominant waterbody, suggesting unmeasured confounding by socioeconomic disadvantage. This may explain our unexpected findings of higher T2D odds with closer proximity to blue space. Our findings highlight the importance of historic and economic context and interrelated factors such as flood risk and lack of waterfront development in blue space research.

Neighborhoods and Intimate Partner Violence Against Women: The Direct and Interactive Effects of Social Ties and Collective Efficacy

This study examines the impact of several indicators of neighborhood social ties (e.g., residents' interactions with each other; residents' ability to recognize outsiders) on intimate partner violence (IPV) against women as well as whether neighborhood collective efficacy's impact on IPV is contingent upon such ties. This study used data from 4,151 women (46% Latina, 33% African American, 17% Caucasian, on average 32 years old) in 80 neighborhoods from the Project on Human Development in Chicago Neighborhoods. We estimated a series of random effects hierarchical Bernoulli models to assess the main and interactive effects of neighborhood social ties and collective efficacy on minor and severe forms of IPV against women. Results indicate that certain neighborhood social ties are associated with higher rates of minor forms of IPV against women (but not severe forms of IPV), and collective efficacy does not appear to influence IPV against women, regardless of the level of individual or neighborhood social ties. Unlike street crime, collective efficacy does not significantly reduce IPV against women, even in neighborhoods with strong social ties that may facilitate awareness of the violence. In fact, perpetrators of minor IPV may enjoy some protective benefit in communities with social ties that make neighbors hesitant to intervene in what some might perceive as "private matters."

Exposure to Community Homicide During Pregnancy and Adverse Birth Outcomes: A Within-Community Matched Design

BACKGROUND

Community violence is an understudied aspect of social context that may affect risk of preterm birth and small-for-gestational age (SGA).

METHODS

We matched California mothers with live singleton births who were exposed to a homicide in their Census tract of residence in 2007-2011 to unexposed mothers within the same tract. We estimated risk differences with a weighted linear probability model, with weights corresponding to the matched data structure. We estimated the average treatment effect on the treated of homicide exposure on the risk of preterm birth and SGA during the preconception period and first and second trimester.

RESULTS

We found a small increase in risk of SGA associated with homicide exposure in the first trimester (0.14% [95% confidence interval (CI) = -0.01%, 0.30%]), but not for exposure during the preconception period (-0.01% [95% CI = -0.17%, 0.15%]) or the second trimester (-0.06% [95% CI = -0.23%, 0.11%]). Risk of preterm birth was not affected by homicide exposure. When women were exposed to homicides during all three exposure windows, there was a larger increase in risk of SGA (1.09% [95% CI = 0.15%, 2.03%]) but not preterm birth (0.14% [95% CI = -0.74%, 1.01%]). Exposure to three or more homicides was also associated with greater risk of SGA (0.78% [95% CI = 0.15%, 1.40%]). Negative controls indicated that residual confounding by temporal patterning was unlikely.

CONCLUSIONS

Homicide exposure during early pregnancy is associated with a small increased risk of SGA.

Societal determinants of violent death: The extent to which social, economic, and structural characteristics explain differences in violence across Australia, Canada, and the United States

In this ecological study, we attempt to quantify the extent to which differences in homicide and suicide death rates between three countries, and among states/provinces within those countries, may be explained by differences in their social, economic, and structural characteristics. We examine the relationship between state/province level measures of societal risk factors and state/province level rates of violent death (homicide and suicide) across Australia, Canada, and the United States. Census and mortality data from each of these three countries were used. Rates of societal level characteristics were assessed and included residential instability, self-employment, income inequality, gender economic inequity, economic stress, alcohol outlet density, and employment opportunities). Residential instability, self-employment, and income inequality were associated with rates of both homicide and suicide and gender economic inequity was associated with rates of suicide only. This study opens lines of inquiry around what contributes to the overall burden of violence-related injuries in societies and provides preliminary findings on potential societal characteristics that are associated with differences in injury and violence rates across populations.

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This study opens lines of inquiry around what contributes to the overall burden of violence-related injuries in societies.

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Differences in homicide and suicide death between and within countries may be explained by social, economic, and structural characteristics.

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Residential instability, self-employment, and income inequality were associated with rates of both homicide and suicide.

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Gender economic inequity was associated with rates of suicide only.

Risk and protective factors for comorbid internalizing and externalizing problems among economically disadvantaged African American youth

Comorbidity of internalizing and externalizing problems and its risk and protective factors have not been well incorporated into developmental research, especially among racial minority youth from high-poverty neighborhoods. The present study identified a latent comorbid factor as well as specific factors underlying internalizing and externalizing problems among 592 African American adolescents living in economically disadvantaged neighborhoods (291 male; M age = 15.9 years, SD = 1.43 years). Stressful life events and racial discrimination were associated with higher comorbid problems, whereas stressful life events and exposure to violence were associated with higher specific externalizing problems. Collective efficacy was associated with both lower specific externalizing problems and lower comorbid problems. Moreover, high collective efficacy buffered the risk effects of stressful life events and racial discrimination on comorbid problems. Our results demonstrated the advantages of latent variable modeling to understanding comorbidity by articulating impacts of risk factors on comorbid and specific components underlying internalizing and externalizing problems. They also highlighted the protective effect of collective efficacy in mitigating risks for these problems. These findings broadly call for more studies on comorbidities in developmental psychopathology among youth from diverse sociocultural backgrounds.

Optimizing matching and analysis combinations for estimating causal effects

Matching methods are common in studies across many disciplines. However, there is limited evidence on how to optimally combine matching with subsequent analysis approaches to minimize bias and maximize efficiency for the quantity of interest. We conducted simulations to compare the performance of a wide variety of matching methods and analysis approaches in terms of bias, variance, and mean squared error (MSE). We then compared these approaches in an applied example of an employment training program. The results indicate that combining full matching with double robust analysis performed best in both the simulations and the applied example, particularly when combined with machine learning estimation methods. To reduce bias, current guidelines advise researchers to select the technique with the best post-matching covariate balance, but this work finds that such an approach does not always minimize mean squared error (MSE). These findings have important implications for future research utilizing matching. To minimize MSE, investigators should consider additional diagnostics, and use of simulations tailored to the study of interest to identify the optimal matching and analysis combination.

Neighborhood Context and Binge Drinking by Race and Ethnicity in New York City

BACKGROUND

Neighborhood context is associated with binge drinking and has significant health, societal, and economic costs. Both binge drinking and neighborhood context vary by race and ethnicity. We examined the relations between neighborhood characteristics--neighborhood norms that are accepting of drunkenness, collective efficacy, and physical disorder--and binge drinking, with a focus on examining race and ethnic-specific relationships.

METHODS

Respondent data were collected through 2005 random digit-dial-telephone survey for a representative sample of New York City residents; neighborhood data were based on the 2005 New York City Housing and Vacancy Survey. Participants were 1,415 past-year drinkers; Whites (n = 877), Blacks (n = 292), and Hispanics (n = 246). Generalized estimating equations were used to estimate population average models.

RESULTS

For the overall sample, neighborhood norms that were more accepting of drunkenness were associated with greater binge drinking (odds ratio [OR] = 1.22; 95% confidence interval [CI] = 1.09, 1.37); collective efficacy and physical disorder were not significant. However, when examining this by race/ethnicity, greater collective efficacy (OR = 0.75; 95% CI = 0.62, 0.91) and greater physical disorder (OR = 0.76; 95% CI = 0.62, 0.93) were associated with less binge drinking for Whites only. Neighborhood norms that were more accepting of drunkenness were associated with binge drinking among Whites (OR = 1.20; 95% CI = 1.05, 1.38) and, while not significant (perhaps due to power), the associations were similar for Hispanics (OR = 1.18; 95% CI = 0.83, 1.68) and slightly lower for Blacks (OR = 1.11; 95% CI = 0.67, 1.84).

CONCLUSIONS

Overall, results suggest that neighborhood characteristics and binge drinking are shaped, in part, by factors that vary across race/ethnicity. Thus, disaggregating data by race/ethnicity is important in understanding binge drinking behaviors.

Neighborhood-level social processes and substantiated cases of child maltreatment

Child maltreatment is a preventable public health problem. Research has demonstrated that neighborhood structural factors (e.g. poverty, crime) can influence the proportion of a neighborhood's children who are victims of maltreatment. A newer strategy is the identification of potentially modifiable social processes at the neighborhood level that can also influence maltreatment. Toward this end, this study examines neighborhood-level data (maltreatment cases substantiated by Illinois' child protection agency, 1995-2005, social processes measured by the Project on Human Development in Chicago Neighborhoods, U.S. Census data, proportions of neighborhoods on public assistance, and crime data) that were linked across clusters of contiguous, relatively homogenous Chicago, IL census tracts with respect to racial/ethnic and socioeconomic composition. Our analysis-an ecological-level, repeated cross-sectional design utilizing random-intercept logit models-with a sensitivity analysis using spatial models to control for spatial autocorrelation-revealed consistent associations between neighborhood social processes and maltreatment. Neighborhoods higher in collective efficacy, intergenerational closure, and social networks, and lower in disorder had lower proportions of neglect, physical abuse, and sexual abuse substantiated cases, controlling for differences in structural factors. Higher collective efficacy and social network size also predicted a lower proportion of substance-exposed infants. This research indicates that strategies to mobilize neighborhood-level protective factors may decrease child maltreatment more effectively than individual and family-focused efforts alone.

Brains in the city: Neurobiological effects of urbanization

With a majority of humans now living in cities, strategic research is necessary to elucidate the impact of this evolutionarily unfamiliar habitat on neural functions and well-being. In this review, both rodent and human models are considered in the evaluation of the changing physical and social landscapes associated with urban dwellings. Animal models assessing increased exposure to artificial physical elements characteristic of urban settings, as well as exposure to unnatural sources of light for extended durations, are reviewed. In both cases, increased biomarkers of mental illnesses such as major depression have been observed. Additionally, applied human research emphasizing the emotional impact of environmental threats associated with urban habitats is considered. Subjects evaluated in an inner-city hospital reveal the impact of combined specific genetic vulnerabilities and heightened stress responses in the expression of posttraumatic stress disorder. Finally, algorithm-based models of cities have been developed utilizing population-level analyses to identify risk factors for psychiatric illness. Although complex, the use of multiple research approaches, as described herein, results in an enhanced understanding of urbanization and its far-reaching effects--confirming the importance of continued research directed toward the identification of putative risk factors associated with psychiatric illness in urban settings.

The impact of neighbourhood violence and social cohesion on smoking behaviours among a cohort of smokers in Mexico

BACKGROUND

Recent increases in violent crime may impact a variety of health outcomes in Mexico. We examined relationships between neighbourhood-level violence and smoking behaviours in a cohort of Mexican smokers from 2011 to 2012, and whether neighbourhood-level social cohesion modified these relationships.

METHODS

Data were analysed from adult smokers and recent ex-smokers who participated in waves 5 and 6 of the International Tobacco Control Mexico survey. Self-reported neighbourhood violence and social cohesion were asked of wave 6 survey participants (n=2129 current and former smokers, n=150 neighbourhoods). Neighbourhood-level averages for violence and social cohesion (ranges 4-14 and 10-25, respectively) were assigned to individuals. We used generalised estimating equations to determine associations between neighbourhood indicators and individual-level smoking intensity, quit behaviours and relapse.

RESULTS

Higher neighbourhood violence was associated with higher smoking intensity (risk ratio (RR)=1.17, 95% CI 1.02 to 1.33), and fewer quit attempts (RR=0.72, 95% CI 0.61 to 0.85). Neighbourhood violence was not associated with successful quitting or relapse. Higher neighbourhood social cohesion was associated with more quit attempts and more successful quitting. Neighbourhood social cohesion modified the association between neighbourhood violence and smoking intensity: in neighbourhoods with higher social cohesion, as violence increased, smoking intensity decreased and in neighbourhoods with lower social cohesion, as violence increased, so did smoking intensity.

CONCLUSIONS

In the context of recent increased violence in Mexico, smokers living in neighbourhoods with more violence may smoke more cigarettes per day and make fewer quit attempts than their counterparts in less violent neighbourhoods. Neighbourhood social cohesion may buffer the impact of violence on smoking intensity.

Alcohol, drug and other prior crimes and risk of arrest in handgun purchasers: protocol for a controlled observational study

BACKGROUND AND OBJECTIVE

Alcohol abuse is common in the USA and is a well-established risk factor for violence. Other drug use and criminal activity are risk factors as well and frequently occur together with alcohol abuse. Firearm ownership is also common; there are >50 million firearm owners in the USA. This study assesses the relationships between alcohol and drug abuse and future violence among firearm owners, which no prior research has done.

DESIGN AND STUDY POPULATION

This records-based retrospective cohort study will involve all persons who legally purchased handguns in California in 2001-approximately 116 000 individuals-with follow-up through the end of 2013.

METHODS

The principal exposures include prior convictions for alcohol-related and drug-related offenses. The primary outcome measure is an arrest following handgun purchase for a violent Crime Index offense: homicide, rape, robbery or aggravated assault. Subjects will be considered at risk for outcome events for only as long as their residence in California can be established independently of outcome events. Covariates include individual characteristics (eg, age, sex, criminal history, firearm purchase history) and community characteristics (eg, demographics, socioeconomic measures, firearm ownership and alcohol outlet density). We will employ survival analytic methods, expressing effects as HRs.

DISCUSSION

The results of this large-scale study are likely to be generalisable and to have important implications for violence prevention policies and programmes.

Framing air pollution epidemiology in terms of population interventions, with applications to multipollutant modeling

Air pollution epidemiology continues moving toward the study of mixtures and multipollutant modeling. Simultaneously, there is a movement in epidemiology to estimate policy-relevant health effects that can be understood in reference to specific interventions. Scaling regression coefficients from a regression model by an interquartile range (IQR) is one common approach to presenting multipollutant health effect estimates. We are unaware of guidance on how to interpret these effect estimates as an intervention. To illustrate the issues of interpretability of IQR-scaled air pollution health effects, we analyzed how daily concentration changes in 2 air pollutants (nitrogen dioxide and particulate matter with aerodynamic diameter ≤ 2.5 μm) related to one another within 2 seasons (summer and winter), within 3 cities with distinct air pollution profiles (Burbank, California; Houston, Texas; and Pittsburgh, Pennsylvania). In each city season, we examined how realistically IQR scaling in multipollutant lag-1 time-series studies reflects a hypothetical intervention that is possible given the observed data. We proposed 2 causal conditions to explicitly link IQR-scaled effects to a clearly defined hypothetical intervention. Condition 1 specified that the index pollutant had to experience a daily concentration change of greater than 1 IQR, reflecting the notion that the IQR is an appropriate measure of variability between consecutive days. Condition 2 specified that the copollutant had to remain relatively constant. We found that in some city seasons, there were very few instances in which these conditions were satisfied (eg, 1 day in Pittsburgh during summer). We discuss the practical implications of IQR scaling and suggest alternative approaches to presenting multipollutant effects that are supported by empirical data.

MILITARY FAMILIES: MEASUREMENT OF COMMUNITY RESOURCE ADEQUACY

Understanding features of community strength both on and off the military installation will help identify and address the needs of military families. This study introduced a measure to identify adequacy of community resources for military families. Using confirmatory factor analysis with data from 717 service users (M age = 37.3 yr., SD = 10.6) representing four large U.S. Army installations, two domains of community resource adequacy were identified: resources on the installation and resources off the installation. This measure could be used in health research with military families and in improving resources available to this population.

Addressing population health and health inequalities: the role of fundamental causes

OBJECTIVES

As a case study of the impact of universal versus targeted interventions on population health and health inequalities, we used simulations to examine (1) whether universal or targeted manipulations of collective efficacy better reduced population-level rates and racial/ethnic inequalities in violent victimization; and (2) whether experiments reduced disparities without addressing fundamental causes.

METHODS

We applied agent-based simulation techniques to the specific example of an intervention on neighborhood collective efficacy to reduce population-level rates and racial/ethnic inequalities in violent victimization. The agent population consisted of 4000 individuals aged 18 years and older with sociodemographic characteristics assigned to match distributions of the adult population in New York City according to the 2000 U.S. Census.

RESULTS

Universal experiments reduced rates of victimization more than targeted experiments. However, neither experiment reduced inequalities. To reduce inequalities, it was necessary to eliminate racial/ethnic residential segregation.

CONCLUSIONS

These simulations support the use of universal intervention but suggest that it is not possible to address inequalities in health without first addressing fundamental causes.

Skewed sex ratios and criminal victimization in India

Although substantial research has explored the causes of India's excessively masculine population sex ratio, few studies have examined the consequences of this surplus of males. We merge individual-level data from the 2004-2005 India Human Development Survey with data from the 2001 India population census to examine the association between the district-level male-to-female sex ratio at ages 15 to 39 and self-reports of victimization by theft, breaking and entering, and assault. Multilevel logistic regression analyses reveal positive and statistically significant albeit substantively modest effects of the district-level sex ratio on all three victimization risks. We also find that higher male-to-female sex ratios are associated with the perception that young unmarried women in the local community are frequently harassed. Household-level indicators of family structure, socioeconomic status, and caste, as well as areal indicators of women's empowerment and collective efficacy, also emerge as significant predictors of self-reported criminal victimization and the perceived harassment of young women. The implications of these findings for India's growing sex ratio imbalance are discussed.

Examination of spatial polygamy among young gay, bisexual, and other men who have sex with men in New York City: the P18 cohort study

The few previous studies examining the influence of the neighborhood context on health and health behavior among young gay, bisexual, and other men who have sex with men (YMSM) have predominantly focused on residential neighborhoods. No studies have examined multiple neighborhood contexts among YMSM or the relationships between sociodemographic characteristics, psychosocial factors, social support network characteristics, health behaviors, and neighborhood concordance. In this study, we assessed spatial polygamy by determining the amount of concordance between residential, social, and sex neighborhoods (defined as boroughs) in addition to examining individual-level characteristics that may be associated with neighborhood concordance. These data come from the baseline assessment of Project 18, a cohort of racially and ethnically diverse YMSM residing in the New York City metropolitan area. Participants (N = 598) provided information on their residential, social, and sex boroughs as well as information on their sociodemographic characteristics, psychosocial factors, social support network characteristics, and health behaviors (e.g., substance use and condomless sex). Descriptive analyses were conducted to examine the distribution of boroughs reported across all three contexts, i.e., residential, social, and sex boroughs. Next, concordance between: (1) residential and social boroughs; (2) residential and sex boroughs; (3) social and sex boroughs; and (4) residential, social, and sex boroughs was assessed. Finally, bivariable analyses were conducted to examine the relationships between sociodemographic characteristics, psychosocial factors, social support network characteristics, and health behaviors in relation to borough concordance. Approximately two-thirds of participants reported concordance between residential/socializing, residential/sex, and sex/socializing boroughs, whereas 25% reported concordance between all three residential/socializing/sex boroughs. Borough concordance varied by some individual-level characteristics. For example, White YMSM and YMSM reporting lower perceived socioeconomic status were significantly more likely to report residential/socializing/sex borough concordance (p < 0.001). With regard to psychosocial factors, YMSM who reported experiencing gay-related stigma in public forums were more likely to report discordant socializing/sex and residential/socializing/sex boroughs (p < 0.001). Greater frequency of communication with network members (≥weekly) was associated with less residential/social borough concordance (p < 0.05). YMSM who reported residential/socializing/sex borough concordance were more likely to report recent (last 30 days) alcohol use, recent marijuana use, and recently engaging in condomless oral sex (all p < 0.05). These findings suggest that spatial polygamy, or an individual moving across and experiencing multiple neighborhood contexts, is prevalent among urban YMSM and that spatial polygamy varies by multiple individual-level characteristics. Future research among YMSM populations should consider multiple neighborhood contexts in order to provide a more nuanced understanding of how and which neighborhood contexts influence the health and well-being of YMSM. This further examination of spatial polygamy (and individual-level characteristics associated with it) may increase understanding of the most appropriate locations for targeted disease prevention and health promotion interventions (e.g., HIV prevention interventions).

Change and stability in ethnic diversity across urban communities: Explicating the influence of social cohesion on perceptions of disorder

A growing body of research shows that perceived community disorder is not solely driven by crime, but is influenced by the community’s social cohesion and ethnic composition. Drawing on two waves of survey data from 2509 and 2651 individuals in Wave 1 and Wave 2 respectively, living in 71 communities in Brisbane Australia, we examine changes in ethnic composition over two time periods and how these changes influence perceived neighbourhood disorder. We also test whether or not social cohesion mediates these associations. Our findings indicate that high proportions of Indigenous residents and high levels of reported crime averaged across time are associated with greater perceived disorder. Whereas increases in household income over time are associated with lower perceived disorder. We also find that social cohesion is strongly associated with perceived disorder over time, but does not mediate the relationship between the racial and ethnic composition of the community and disorder. Yet when a community’s social cohesion is considered, the effect of increasing household income becomes non-significant.