Faculty Bibliography

Political-economic transitions in the Soviet Union, Indonesia, and China, but not the Philippines, were followed by HIV epidemics among drug users. Wars also may sometimes increase HIV risk. Based on similarities in some of the causal pathways through which wars and transitions can affect HIV risk, we use the term "Big Events" to include both. We first critique several prior epidemiological models of Big Events as inadequately incorporating social agency and as somewhat imprecise and over-generalizing in their sociology. We then suggest a model using the following concepts: first, event-specific HIV transmission probabilities are functions of (a) the probability that partners are infection-discordant; (b) the infection-susceptibility of the uninfected partner; (c) the infectivity of the infected--as well as (d) the behaviours engaged in. These probabilities depend on the distributions of HIV and other variables in populations. Sexual or injection events incorporate risk behaviours and are embedded in sexual and injection partnership patterns and community networks, which in turn are shaped by the content of normative regulation in communities. Wars and transitions can change socio-economic variables that can sometimes precipitate increases in the numbers of people who engage in high-risk drug and sexual networks and behaviours and in the riskiness of what they do. These variables that Big Events affect may include population displacement; economic difficulties and policies; police corruption, repressiveness, and failure to preserve order; health services; migration; social movements; gender roles; and inter-communal violence--which, in turn, affect normative regulation, youth alienation, networks and behaviours. As part of these pathways, autonomous action by neighbourhood residents, teenagers, drug users and sex workers to maintain their economic welfare, health or happiness may affect many of these variables or otherwise mediate whether HIV epidemics follow transitions. We thus posit that research on whether and how these interacting causal pathways and autonomous actions are followed by drug-related harm and/or HIV or other epidemics can help us understand how to intervene to prevent or mitigate such harms.

HIV continues to be transmitted at unacceptably high rates among African Americans, and most HIV-prevention interventions have focused on behavioral change. To theorize additional approaches to HIV prevention among African Americans, we discuss how sexual networks and drug-injection networks are as important as behavior for HIV transmission. We also describe how higher-order social structures and processes, such as residential racial segregation and racialized policing, may help shape risk networks and behaviors. We then discuss 3 themes in African American culture-survival, propriety, and struggle-that also help shape networks and behaviors. Finally, we conclude with a discussion of how these perspectives might help reduce HIV transmission among African Americans.

The concept of the "risk environment"--defined as the "space ... [where] factors exogenous to the individual interact to increase the chances of HIV transmission"--draws together the disciplines of public health and geography. Researchers have increasingly turned to geographic methods to quantify dimensions of the risk environment that are both structural and spatial (e.g., local poverty rates). The scientific power of the intersection between public health and geography, however, has yet to be fully mined. In particular, research on the risk environment has rarely applied geographic methods to create neighbourhood-based measures of syringe exchange programmes (SEPs) or of drug-related law enforcement activities, despite the fact that these interventions are widely conceptualized as structural and spatial in nature and are two of the most well-established dimensions of the risk environment. To strengthen research on the risk environment, this paper presents a way of using geographic methods to create neighbourhood-based measures of (1) access to SEP sites and (2) exposure to drug-related arrests, and then applies these methods to one setting (New York City [NYC]). NYC-based results identified substantial cross-neighbourhood variation in SEP site access and in exposure to drug-related arrest rates (even within the subset of neighbourhoods nominally experiencing the same drug-related police strategy). These geographic measures--grounded as they are in conceptualizations of SEPs and drug-related law enforcement strategies--can help develop new arenas of inquiry regarding the impact of these two dimensions of the risk environment on injectors' health, including exploring whether and how neighbourhood-level access to SEP sites and exposure to drug-related arrests shape a range of outcomes among local injectors.

Pharmacies that sell over-the-counter (OTC) syringes are a major source of sterile syringes for injection drug users in cities and states where such sales are legal. In these cities and states, however, black injectors are markedly less likely to acquire syringes from pharmacies than white injectors. The present analysis documents spatial and temporal trends in OTC pharmacy access in New York City health districts over time (2001-2006) and investigates whether these trends are related to district racial/ethnic composition and to local need for OTC pharmacies. For each year of the study period, we used kernel density estimation methods to characterize spatial access to OTC pharmacies within each health district. Higher values on this measure indicate better access to these pharmacies. "Need" was operationalized using two different measures: the number of newly diagnosed injection-related AIDS cases per 10,000 residents (averaged across 1999-2001), and the number of drug-related hospital discharges per 10,000 residents (averaged across 1999-2001). District sociodemographic characteristics were assessed using 2000 US decennial census data. We used hierarchical linear models (HLM) for descriptive and inferential analyses and investigated whether the relationship between need and temporal trajectories in the Expanded Syringe Access Demonstration Program access varied by district racial/ethnic composition, controlling for district poverty rates. HLM analyses indicate that the mean spatial access to OTC pharmacies across New York City health districts was 12.71 in 2001 and increased linearly by 1.32 units annually thereafter. Temporal trajectories in spatial access to OTC pharmacies depended on both need and racial/ethnic composition. Within high-need districts, OTC pharmacy access was twice as high in 2001 and increased three times faster annually, in districts with higher proportions of non-Hispanic white residents than in districts with low proportions of these residents. In low-need districts, "whiter" districts had substantially greater baseline access to OTC pharmacies than districts with low proportions of non-Hispanic white residents. Access remained stable thereafter in low-need districts, regardless of racial/ethnic composition. Conclusions were consistent across both measures of "need" and persisted after controlling for local poverty rates. In both high- and low-need districts, spatial access to OTC pharmacies was greater in "Whiter" districts in 2001; in high-need districts, access also increased more rapidly over time in "whiter" districts. Ensuring equitable spatial access to OTC pharmacies may reduce injection-related HIV transmission overall and reduce racial/ethnic disparities in HIV incidence among injectors.

OBJECTIVES: We investigated the relationship between the depressive symptoms of older adults over time and the characteristics of the neighborhoods in which they live. METHODS: We surveyed a random sample of 1325 New York City residents aged 50 years or older in 2005 and conducted 808 follow-up interviews in 2007. We assessed the compositional characteristics of the respondents' neighborhoods at a census-tract level and determined the relationships between these characteristics and changes in respondents' depressive symptoms. RESULTS: In multivariable models that adjusted for individual-level covariates including income, a range of neighborhood characteristics predicted worsening depressive symptoms. Factor analysis suggested that these characteristics operated in 3 clusters: neighborhood socioeconomic influences, residential stability, and racial/ethnic composition, with positive neighborhood socioeconomic influences being significantly protective against worsening symptoms. Life stressors, personality trait neuroticism, African American race, and daily baseline contact with social networks were also associated with worsening symptoms. CONCLUSIONS: An older adult's neighborhood of residence is an important determinant of his or her mental health. Those making efforts to improve mental health among the elderly need to consider the role of residential context in improving or impairing mental health.

BACKGROUND: Homicide contributes substantially to the burden of death in the US and remains a key contributor to the gap in white-black life expectancy. It has been hypothesized that "broken-windows" policing is associated with lower homicide rates and that physical disorder may mediate this association. However, the empiric evidence is limited and conflicting. METHODS: We used pooled, cross-sectional time-series data for 74 New York City (NYC) Police Precincts between 1990 and 1999 to test the relation between neighborhood misdemeanor policing (an indicator of physical order) and homicide in NYC in the 1990s. We applied Bayesian hierarchical models, including a random effect of place, to account for serial correlations in homicide across adjacent neighborhoods. RESULTS: An increase of 5000 misdemeanor arrests in a precinct with 100,000 people was associated with a reduction of 3.5 homicides (95% credible interval = -5.00 to -1.00). However, increased misdemeanor arrests were associated with lower physical order (posterior median = -0.015 [-0.025 to -0.01]), and physical order was unrelated to homicide. CONCLUSIONS: Our study replicated prior findings suggesting that misdemeanor policing reduces homicide rates, but offered no support for the hypothesis that physical disorder is a mediator of the impact of such policing. Factors responsible for the dramatic decline in US homicides in the last decade remain unclear.

OBJECTIVE: To characterize the influence of the residential neighborhood of older adults on the prevalence of disability. METHODS: We combined Census data on disability in older adults living in New York City with environmental information from a comprehensive geospatial database. We used factor analysis to derive dimensions of compositional and physical neighborhood characteristics and linear regression to model their association with levels of disability. Measures of neighborhood collective efficacy were added to these models to explore the impact of the social environment. RESULTS: Low neighborhood socioeconomic status, residential instability, living in areas with low proportions of foreign born and high proportions of Black residents, and negative street characteristics were associated with higher prevalence of both "physical" disability and "going outside the home" disability. High crime levels were additionally associated with physical disability, although this relationship disappeared when misdemeanor arrests were removed from the crime variable. Low levels of collective efficacy were associated with more going-outside-the-home disability, with racial/ethnic composition dropping out of this model to be replaced by an interaction term. CONCLUSION: The urban environment may have a substantial impact on whether an older adult with a given level of functional impairment is able to age actively and remain independent.

INTRODUCTION: The Centers for Disease Control and Prevention (CDC) advise repeat HIV testing for partners of HIV-infected persons; injection drug users and their sex partners; individuals with recent multiple partnerships and their sex partners; those involved in sex trade; and men who have sex with men. Additional social and behavioral variables may be useful for identifying priority populations. METHODS: We analyzed data collected during a social network study conducted in a Brooklyn, NY, neighborhood to identify social and behavioral characteristics of respondents (N = 343) involved in HIV-discordant, herpes simplex virus-2- discordant, and chlamydia-discordant partnerships. RESULTS: HIV partnership discordance was associated with injection drug use but was generally not associated with sexual behaviors including multiple partnerships and sex trade. herpes simplex virus-2 and chlamydia partnership discordance were associated with multiple partnerships, sex trade, and same sex partnership history. Additional correlates of sexually transmitted infection (STI)/HIV-discordant partnerships included older age (>or=25 years), noninjection drug use, and incarceration history. Analyses suggested that screening tools composed of CDC-recommended sexual risk and injection drug indicators plus indicators of older age, noninjection drug use, and incarceration were more effective in identifying STI/HIV priority populations than tools composed of CDC indicators alone. CONCLUSIONS: Screening tools that include social and behavioral indicators may improve STI/HIV case-finding effectiveness.

OBJECTIVES: We examined racial/ethnic disparities in HIV infection among injection drug users (IDUs) before and after implementation of large-scale syringe exchange programs in New York City. METHODS: Participants were recruited from IDUs entering the Beth Israel drug detoxification program in New York City. Participants (n = 1203) recruited from 1990 through 1994, prior to large-scale syringe exchange programs (pre-exchange), were compared with 1109 participants who began injecting in 1995 or later and were interviewed in 1995 through 2008 (post-exchange). RESULTS: There were large differences in HIV prevalence among pre-exchange vs post-exchange participants (African Americans, 57% vs 15%; Hispanics, 53% vs 5%; Whites, 27% vs 3%). Pre- and post-exchange relative disparities of HIV prevalence were similar for African Americans vs Whites (adjusted odds ratio [AOR] = 3.46, 95% confidence interval [CI] = 2.41, 4.96 and AOR = 4.02, 95% CI = 1.67, 9.69, respectively) and Hispanics vs Whites (AOR = 1.76, 95% CI = 1.49, 2.09 and AOR = 1.49, 95% CI = 1.02, 2.17). Racial/ethnic group differences in risk behavior did not explain differences in HIV prevalence. CONCLUSIONS: New interventions are needed to address continuing disparities in HIV infection among IDUs, but self-reported risk behaviors by themselves may not be adequate outcome measures for evaluating interventions to reduce racial/ethnic disparities in HIV infection.