Racial residential segregation and low birth weight in Michigan's metropolitan areas

Objectives. We examined the influence of racial residential segregation, independent of neighborhood economic factors, on the overall and specific etiological risks of low birth weight.Methods. We geocoded all singleton births in Michigan metropolitan areas during 2000 to census tracts. We used hierarchical generalized linear models to investigate the association between low birth weight (< 2500 g) and neighborhood-level economic and racial segregation, controlling for individual and neighborhood characteristics. We analyzed competing risks of the 2 etiologies of low birth weight: intrauterine growth restriction and preterm birth.Results. Living in a Black segregated area was associated with increased odds (odds ratio [OR] = 1.15; 95% confidence interval [CI] = 1.03, 1.29; P < .05) of low birth weight after adjusting for individual- and tract-level measures. The analysis suggested that the association between low birth weight and racial segregation was attributable primarily to increased risk of intrauterine growth restriction (OR = 1.19; 95% CI = 1.03, 1.37; P < .05).Conclusions. Odds of low birth weight are higher in racially segregated Black neighborhoods in Michigan''s metropolitan areas, independent of economic factors. The association appears to operate through intrauterine growth restriction rather than preterm birth.As the leading cause of death among non-Hispanic Black infants and second-leading cause of death among non-Hispanic White infants, complications related to short gestation and low birth weight represent a significant clinical and public health issue.^1–3 Low birth weight also leads to long-term health consequences through increased rates of childhood and adult chronic diseases.^3–6 Racial disparities in rates of low birth weight have persisted even as total infant mortality has declined and prenatal care utilization among women of color has increased.^1–3 Because differences in individual-level risk factors cannot completely explain the differences in outcomes for White and Black mothers,^3,7 researchers have begun investigating contextual influences on racial disparities in birth outcomes.^3,8Racial segregation is a contextual factor that might contribute to racial disparities in low birth weight by isolating Blacks from the resources and opportunities found more frequently in White communities.^9–13 Residents in Black segregated neighborhoods accumulate less home equity,^14,15 have decreased access to quality primary education,¹⁶ and are exposed to greater residential and economic instability than are residents of nonsegregated communities.⁹ The accumulation of disadvantages in racially isolated neighborhoods could lead to negative birth outcomes for women by limiting opportunities associated with improved health (e.g., educational opportunities or access to quality medical care) and by exposing them to increased stress from neighborhood-level factors.Evidence from a small number of studies suggests that low birth weight is associated with racial residential segregation.^17–24 With few exceptions,^17,25,26 studies link metropolitan-level segregation or the percentage of Black residents in a community to low birth weight. However, because isolation is inherently spatial, to understand how the racial isolation of an individual mother''s neighborhood affects her pregnancy outcomes, isolation is most appropriately measured by considering her neighborhood along with its immediate surroundings (e.g., bordering neighborhoods) rather than by the metropolitan area or a single neighborhood.¹⁷Some authors have argued that racial segregation simply serves as a proxy for economic segregation.^27,28 By contrast, we posit that racial segregation is a distinct form of neighborhood-level disadvantage that presents an increased risk for low birth weight beyond that caused by economic segregation. Sociologists have shown that, even in the presence of economic segregation, the circumstances of racially segregated Black neighborhoods differ from those of White neighborhoods at similar socioeconomic levels.^29–32 This means that although residents of Black middle-class neighborhoods may live in residential areas that are separate from poor Black neighborhoods, they have greater exposure than do middle-class Whites to negative contextual factors and have fewer resources in their vicinity. This also suggests that any attempt to distinguish between the effects of racial and economic segregation on low birth weight requires that economic segregation also be measured spatially, taking a mother''s neighborhood and its immediate surroundings into account.It is also important to consider that the drivers of low birth weight—preterm birth and intrauterine growth restriction—have distinct physiological mechanisms.^33–35 Assessing the degree to which racial isolation is associated with each can provide important insight into the etiological mechanisms relating racial segregation to low birth weight. Spontaneous preterm birth is commonly precipitated by an infection,^36–40 which could be associated with racial segregation if, for instance, racial segregation reduces access to quality care.²⁵ Intrauterine growth restriction, on the other hand, typically stems from a chronic deficiency in oxygen and nutrient delivery to the fetus.^41–46 Chronic stress associated with the circumstances of racially isolated neighborhoods might affect placental vasculature function, creating an oxygen–nutrient insufficiency that leads to intrauterine growth restriction.⁴⁷ We know of no research that has considered the competing risks of growth restriction and preterm birth in the relationship of neighborhood environments with low birth weight.We examined births to mothers living in Michigan metropolitan areas to ascertain whether neighborhood racial segregation was associated with low birth weight independent of economic factors. We explicitly captured the spatial nature of both racial and economic segregation through a localized segregation index. We also analyzed the degree to which racial segregation was associated with different etiologies of low birth weight.     

A Systematic Review of Neighborhood Disparities in Point-of-Sale Tobacco Marketing

We systematically reviewed evidence of disparities in tobacco marketing at tobacco retailers by sociodemographic neighborhood characteristics. We identified 43 relevant articles from 893 results of a systematic search in 10 databases updated May 28, 2014. We found 148 associations of marketing (price, placement, promotion, or product availability) with a neighborhood demographic of interest (socioeconomic disadvantage, race, ethnicity, and urbanicity).Neighborhoods with lower income have more tobacco marketing. There is more menthol marketing targeting urban neighborhoods and neighborhoods with more Black residents. Smokeless tobacco products are targeted more toward rural neighborhoods and neighborhoods with more White residents. Differences in store type partially explain these disparities.There are more inducements to start and continue smoking in lower-income neighborhoods and in neighborhoods with more Black residents. Retailer marketing may contribute to disparities in tobacco use. Clinicians should be aware of the pervasiveness of these environmental cues.Tobacco products and their marketing materials are ubiquitous in US retailers from pharmacies to corner stores.1 A similar presence is found across the globe, except in countries that ban point-of-sale (POS) tobacco marketing (e.g., Australia, Canada, Thailand2). In the United States, the POS has become the main communications channel for tobacco marketing3,4 and is reported as a source of exposure to tobacco marketing by more than 75% of US youths.5 Burgeoning evidence6,7 suggests that marketing at the POS is associated with youths’ brand preference,8 smoking initiation,9 impulse purchases,10,11 and compromised quit attempts.12,13The marketing of tobacco products is not uniform; it is clear from industry documents that the tobacco industry has calibrated its marketing to target specific demographic groups defined by race,14 ethnicity,15 income,16 mental health status,17 gender,18,19 and sexual orientation.20 Framed as an issue of social and environmental justice,14 research has documented historical racial, ethnic, and socioeconomic disparities in the presence of tobacco billboards,21–25 racial disparities in total tobacco marketing volume,24 and targeting of menthol cigarettes to communities with more Black residents.25,26 Targeted marketing of a consumer product that kills up to half27 of its users when used as directed exacerbates inequities in morbidity and mortality. Smoking is estimated to be responsible for close to half of the difference in mortality between men in the lowest and highest socioeconomic groups.28 However, evidence of marketing disparities is scattered across multiple disciplines and marketing outcomes, such as product availability, advertising quantity, presence of promotional discounts, and price. A synthesis of this literature would provide valuable information for intervention on tobacco marketing in the retail environment and inform etiological research on health disparities.To address this gap in the literature, we systematically reviewed observational studies that examined the presence and quantity of POS tobacco marketing to determine the extent to which marketing disparities exist by neighborhood demographic characteristic (i.e., socioeconomic disadvantage, race, ethnicity, and urbanicity).     

Neighborhood social disorganization and the acquisition of trichomoniasis among young adults in the United States

Objectives. We examined relationships between neighborhood social disorganization and trichomoniasis among young US adults.Methods. We employed multilevel logistic regression modeling with secondary data from wave III of the National Longitudinal Study of Adolescent Health (2001–2002). The dependent variable—trichomoniasis—was measured via urine testing. The measures for neighborhood social disorganization were derived from the 2000 US Census—racial and ethnic composition, concentrated poverty, and residential instability. The sample comprised 11 370 individuals across 4912 neighborhoods.Results. Trichomoniasis was more likely in neighborhoods with higher concentrations of Black residents (adjusted odds ratio [AOR] = 1.16; 95% confidence interval [CI] = 1.03, 1.30). However, this association was mediated by neighborhood concentrated poverty. Furthermore, young adults who lived in neighborhoods with higher concentrations of poverty were significantly more likely to have trichomoniasis (AOR = 1.25; 95% CI = 1.07, 1.46). Neither immigrant concentration nor residential instability was significantly associated with trichomoniasis.Conclusions. These findings strengthen the evidence that neighborhood structural conditions are associated with individual sexually transmitted infection (STI) acquisition. Research is needed to explore the mechanisms through which these conditions influence STI. In addition, STI-prevention programs that include structural interventions targeting neighborhood disadvantage are needed.Adolescents and young adults are at increased risk for sexually transmitted infections (STIs) because of a complex interplay of biological, behavioral, and developmental factors.¹ Nearly half of all STIs diagnosed in the United States annually are among adolescents and young adults^1,2 despite national priority goals aimed at reducing infection rates.³ Trichomoniasis, a common and easily curable STI,¹ is of increasing concern because the infection facilitates HIV acquisition and transmission through mucosal inflammation of the genital tract and alterations in the innate immune response. ^4-7 The infection is caused by the protozoa, Trichomonas vaginalis, and is typically transmitted via penis-to-vagina or vulva-to-vulva contact.¹ Infected persons are often asymptomatic or experience only mild symptoms,¹ which can hinder early detection and treatment and increase the risk of STIs and HIV.In the United States, the prevalence of trichomoniasis is difficult to ascertain because routine screening currently is not recommended nor is the reporting of positive results required.^1,4 According to urine assay data from the National Longitudinal Study of Adolescent Health (Add Health), the prevalence of trichomoniasis among the young adult population in 2001–2002 was approximately 2.3%.⁷ The study also found that women were at greater risk than were men (2.8% vs 1.7%) as were non-Hispanic Black (6.9%) and Latino (2.1%) youths compared with their non-Hispanic White peers (1.2%).⁷ In other studies of adult women, individual risk factors for trichomoniasis included poverty, lower education, douching, non-Hispanic Black race/ethnicity, and greater numbers of lifetime sexual partners.^8,9 Among clinic samples of adolescent women, research found trichomoniasis to be associated with older male sexual partners, casual sexual activity, marijuana use, and delinquency.¹⁰However, to date, no studies have examined the role of the broader structural context in shaping trichomoniasis risk, despite theory and previous STI research suggesting that the neighborhood environment may play a role. According to social disorganization theory,^11–14 key indicators of neighborhood structural disadvantage (i.e., racial/ethnic composition, concentrated poverty, and residential instability) influence health outcomes by weakening social ties, reducing access to institutional resources, and limiting exposure to positive role models, conventional social norms, and collective efficacy. Findings from previous research examining other STIs support the hypothesis that neighborhood contexts influence STI prevalence. For example, with respect to racial and ethnic composition, studies have found that gonorrhea rates were higher in cities and neighborhoods with greater proportions of Black residents.^15,16 Furthermore, in an analysis of Chicago neighborhoods, the incidence rates of gonorrhea and chlamydia were higher for neighborhoods in which more than 60% of the residents were Black compared with those in which more than 60% of residents were Hispanic, which suggests that segregated Hispanic ethnic enclaves may be protective of STI compared with segregated Black communities.¹⁷ Researchers hypothesize that the residential segregation of Black communities has contributed to the pervasive Black-White disparities in STI through discrimination processes, which in turn has led to greater concentration of poverty, lower male-to-female gender ratios due to the disproportionate incarceration and mortality of Black men, and closed, racially segregated sexual networks that facilitate the transmission of infection.^18–20In addition, the role of community poverty in shaping STI risk has been examined extensively and found to be positively associated with rates of chlamydia, gonorrhea, syphilis, and HIV in cross-sectional^{15,17,21–23} and longitudinal analyses.¹⁶ Other socioeconomic factors, such as unemployment^17,24 and lower educational attainment,^16,17 have also been linked to higher rates of chlamydia and gonorrhea. Research on the effects of residential instability on STI is limited, but the single study that examined these relationships found greater residential instability was associated with fewer self-reported STIs among a national sample of adolescents.²⁴ Depending on the context, perhaps residential instability could increase STI risk by disrupting social support ties and informal social control measures or reduce STI risk by dispersing closed sexual networks that facilitate infection transmission.Although the aforementioned studies have illustrated links between neighborhood social disorganization and a variety of STIs, limitations exist. First, the majority have been ecological studies, in which the outcomes were measured as community STI rates and no adjustment was made for potential confounding relationships with individual-level data.^{15–17,21–23} Consequently, inferences can be made only about the community, and individual variation in the outcome cannot be ascertained.²⁵ Second, although 1 study examined individual STI, the measure was based on self-report,²⁴ which potentially increases bias because of underreporting as well as unrecognized or undiagnosed infection. In addition, the study only focused on STI in general, which could limit our understanding of unique relationships with specific infectious organisms. Third, data sources of previous research tend to be at local or state levels,^{15–17,21–23} which limits external validity of the findings. Therefore, the purpose of our research was to examine relationships between neighborhood social disorganization and trichomoniasis among young adults in the United States. Our research builds on previous studies in 3 significant ways: (1) we examined multiple levels of analysis, which enabled us to simultaneously examine the independent relationships between individual and neighborhood variables and individual acquisition of trichomoniasis, (2) we examined a more refined measure of STI through the use of urine screening, and (3) we examined data from a large national data set—Add Health.     

Health status, neighborhood socioeconomic context, and premature mortality in the United States: The National Institutes of Health-AARP Diet and Health Study

Objectives. We examined whether the risk of premature mortality associated with living in socioeconomically deprived neighborhoods varies according to the health status of individuals.Methods. Community-dwelling adults (n = 566 402; age = 50–71 years) in 6 US states and 2 metropolitan areas participated in the ongoing prospective National Institutes of Health–AARP Diet and Health Study, which began in 1995. We used baseline data for 565 679 participants on health behaviors, self-rated health status, and medical history, collected by mailed questionnaires. Participants were linked to 2000 census data for an index of census tract socioeconomic deprivation. The main outcome was all-cause mortality ascertained through 2006.Results. In adjusted survival analyses of persons in good-to-excellent health at baseline, risk of mortality increased with increasing levels of census tract socioeconomic deprivation. Neighborhood socioeconomic mortality disparities among persons in fair-to-poor health were not statistically significant after adjustment for demographic characteristics, educational achievement, lifestyle, and medical conditions.Conclusions. Neighborhood socioeconomic inequalities lead to large disparities in risk of premature mortality among healthy US adults but not among those in poor health.Research dating back to at least the 1920s has shown that the United States has experienced persistent and widening socioeconomic disparities in premature mortality over time.^1–5 However, it has been unclear whether socioeconomic inequalities affect the longevity of persons in good and poor health equally. Socioeconomic status (SES) and health status are interrelated,^6–8 and both are strong independent predictors of mortality.⁹ Low SES is associated with greater risk of ill health and premature death,^{1–5,8,10–13} partly attributable to disproportionately high prevalence of unhealthful lifestyle practices^10,14,15 and physical and mental health conditions.^13,16 Correspondingly, risk of premature mortality is higher in poor than in more affluent areas.^16,17 Although the association between neighborhood poverty and mortality is independent of individual-level SES,^17,18 aggregation of low-SES populations in poor areas may contribute to variations in health outcomes across neighborhoods. Conversely, economic hardships resulting from ill health may lead persons in poor physical or mental health to move to poor neighborhoods.¹⁹ This interrelatedness may create spurious associations between neighborhood poverty and mortality.Although previous studies have found that the risk of premature death associated with poor health status varies according to individuals'' SES,^20,21 no published studies have examined whether the relative risks for premature mortality associated with living in neighborhoods with higher levels of socioeconomic deprivation vary by health status of individuals. Clarifying these relationships will inform social and public health policies and programs that aim to mitigate the health consequences of neighborhood poverty.^22,23We used data from a large prospective study to examine whether the risk of premature mortality associated with neighborhood socioeconomic context differs according to health status at baseline and remains after adjustment for person-level risk factors for mortality, such as SES, lifestyle practices, and chronic medical illnesses.     

Life-Course Socioeconomic Position and Incidence of Diabetes Mellitus Among Blacks and Whites: The Alameda County Study, 1965�C1999

Objectives. We examined associations between several life-course socioeconomic position (SEP) measures (childhood SEP, education, income, occupation) and diabetes incidence from 1965 to 1999 in a sample of 5422 diabetes-free Black and White participants in the Alameda County Study.Methods. Race-specific Cox proportional hazard models estimated diabetes risk associated with each SEP measure. Demographic confounders (age, gender, marital status) and potential pathway components (physical inactivity, body composition, smoking, alcohol consumption, hypertension, depression, access to health care) were included as covariates.Results. Diabetes incidence was twice as high for Blacks as for Whites. Diabetes risk factors independently increased risk, but effect sizes were greater among Whites. Low childhood SEP elevated risk for both racial groups. Protective effects were suggested for low education and blue-collar occupation among Blacks, but these factors increased risk for Whites. Income was protective for Whites but not Blacks. Covariate adjustment had negligible effects on associations between each SEP measure and diabetes incidence for both racial groups.Conclusions. These findings suggest an important role for life-course SEP measures in determining risk of diabetes, regardless of race and after adjustment for factors that may confound or mediate these associations.Diabetes mellitus is a major cause of morbidity and mortality in the United States.^1,2 Type 2 diabetes disproportionately affects Hispanics, as well as non-Hispanic Black Americans, American Indians/Alaska Natives, and some Asian/Pacific Islander groups. In the United States, members of racial and ethnic minority groups are almost twice as likely to develop or have type 2 diabetes than are non-Hispanic Whites.^2–5 Significant racial and ethnic differences also exist in the rates of diabetes-related preventive services, quality of care, and disease outcomes.^6–10Researchers have attempted to determine why, relative to Whites, members of racial and ethnic minority groups are disproportionately affected by diabetes. For example, compared with White Americans, Black Americans are presumed to have stronger genetic^5,11 or physiological^11–13 susceptibility to diabetes, or greater frequency or intensity of known diabetes risk factors, such as obesity, physical inactivity, and hypertension.^14–17Black Americans also are more likely than are White Americans to occupy lower socioeconomic positions.¹⁸ Low socioeconomic position (SEP) across the life course is known to influence the prevalence^19–24 and incidence^3,19,25–30 of type 2 diabetes. The risk of diabetes also is greater for people who are obese,^3,17,31 physically inactive,^3,32 or have hypertension,^33,34 all of which are conditions more common among people with lower SEP.^16,35–37Several studies have focused on the extent to which socioeconomic factors, body composition (i.e., weight, height, body mass index, and waist circumference), and behaviors explain the excess risk of diabetes attributed to race.^4,12,19,30 For example, 2 separate studies, one with data from the Health and Retirement Study¹⁹ and the other with data from the Atherosclerosis Risk in Communities Study,³⁰ used race to predict diabetes incidence. Attempting to separate the direct and indirect effects of race on diabetes,³⁸ these studies assessed, via statistical adjustment, which socioeconomic measures and diabetes-related risk factors, when adjusted, could account for the excess risk among Black participants relative to White participants.^19,30 Adjustment for education lessened the effect of Black race on diabetes incidence in the Atherosclerosis Risk in Communities Study.³⁰ In the Health and Retirement Study, excess risk attributed to Black race was not explained by early-life socioeconomic disadvantage, but it was reduced after adjustment for education and later-life economic resources.¹⁹ The validity of this analytic approach has been challenged, however, because the socioeconomic measures used were assumed to have the same meaning across all racial/ethnic groups, a questionable assumption³⁸ in the United States, especially in 1965.We sought to explore the predictive effects of several life-course socioeconomic factors on the incidence of diabetes among both Black and White Americans. We examined demographic confounders (age, gender, marital status) and diabetes risk factors (obesity, large waist circumference, physical inactivity, high blood pressure, depression, access to health care) as possible mediators of the observed associations between SEP and incident diabetes (i.e., the development of new cases of diabetes over time).     

Neighborhoods and obesity in later life

Objectives. We examined the influence of neighborhood environment on the weight status of adults 55 years and older.Methods. We conducted a 2-level logistic regression analysis of data from the 2002 wave of the Health and Retirement Study. We included 8 neighborhood scales: economic advantage, economic disadvantage, air pollution, crime and segregation, street connectivity, density, immigrant concentration, and residential stability.Results. When we controlled for individual- and family-level confounders, living in a neighborhood with a high level of economic advantage was associated with a lower likelihood of being obese for both men (odds ratio [OR] = 0.86; 95% confidence interval [CI] = 0.80, 0.94) and women (OR = 0.83; 95% CI = 0.77, 0.89). Men living in areas with a high concentration of immigrants and women living in areas of high residential stability were more likely to be obese. Women living in areas of high street connectivity were less likely to be overweight or obese.Conclusions. The mechanisms by which neighborhood environment and weight status are linked in later life differ by gender, with economic and social environment aspects being important for men and built environment aspects being salient for women.Over the past few decades the prevalence of obesity has been rising for men and women across all age groups, including the elderly.¹ For example, in 2001 to 2002 in the United States, about 1 in 3 adults 60 years or older was obese.² This trend raises concerns because excess weight is associated with a number of chronic health conditions, including diabetes, high blood pressure, asthma, and arthritis.³ Moreover, obesity can have very important implications for publicly financed health care.⁴ Recent research suggests that a number of demographic, socioeconomic, and family factors⁵ influence obesity, but the role of the neighborhood context has not been fully explored.Excess weight results from an energy imbalance in which caloric intake exceeds energy expenditures, the latter closely related to physical activity. The neighborhood environment may influence energy intake (through its influence on food availability⁶) and energy expenditure (by facilitating or impeding physical activity). For example, the presence of supermarkets in the neighborhood is associated with higher fruit and vegetable intake,⁷ whereas eating at fast-food restaurants is associated with a high-fat diet and higher body mass index (BMI; weight in kilograms divided by height in meters squared).⁸ In terms of physical activity, individuals living in neighborhoods with less crime,^9–13 higher land-use mix,¹⁴ higher street connectivity,^11,14,15 higher residential density,^11,14 a greater number of destinations,^9,16 better aesthetics,^9,10,17 and sidewalks^10,12,17,18 tend to walk more often.^19,20Only a handful of studies linking neighborhood features to late-life obesity have focused on older adults.^{11,13,16,21–23} National studies are particularly lacking for the elderly. Yet evidence from national studies of adults of all ages suggests plausible connections between obesity and neighborhood factors. Using the 1990 to 1994 waves of the National Health Interview Survey, for example, Boardman et al.²⁴ found that adults residing in neighborhoods with a high concentration of poverty and in neighborhoods with a high percentage of Blacks were more likely to be obese. In another study, Robert and Reither²⁵ found that higher community socioeconomic disadvantage was related to higher BMI among women but not among men. Because these studies had very limited characterizations of the neighborhoods, the mechanism through which poor neighborhoods result in obesity remains unclear. It could be, for instance, that poor neighborhoods tend to have fewer supermarkets^26–28 and more-limited access to places for physical activity.^29,30Using a large, nationally representative survey, we examined the relationship between the economic, built, and social environments and weight status among men and women 55 years and older. We included 8 previously validated neighborhood scales reflecting neighborhood safety and segregation, concentration of immigrants, air pollution, residential stability, connectivity, density or access, and high and low neighborhood socioeconomic status.³¹ We modeled both obesity and overweight status by using multilevel modeling techniques in which we controlled for detailed individual- and family-level confounders.     

Neighborhood Characteristics and Change in Depressive Symptoms Among Older Residents of New York City

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.Depression is an important cause of morbidity in the general community.¹ The prevalence of depression is high among elderly persons, and longitudinal studies have found modest increases in depressive symptoms with age.^2–4 The incidence of depression peaks in early adult life, but there appears to be a secondary peak in incidence among people in their 50s, suggesting that the transition to older age may present specific risks for depression.⁵ Depression is associated with significant disability among older adults and may place their functional independence at risk.⁶ At least 1 longitudinal study has also suggested that older African Americans may be at increased risk of symptoms of depression compared with older White adults.⁷Although a number of individual-level factors are known to increase the risk of depression,^8–10 it has long been thought that the physical and social environments in which people live may also influence their mental health.^11–13 The environment may play a particularly important role in the mental health of older adults, who, compared with younger adults, are more likely to spend time in their neighborhood of residence, more likely to suffer from disabilities that may be exacerbated by their environments,¹⁴ and are more vulnerable to threats to their safety.^15–17A number of theories have been proposed to explain this association between neighborhood characteristics and depression. Researchers have drawn on systemic theory to propose that neighborhoods characterized by higher levels of poverty and residential instability have lower levels of social cohesion and lower levels of control over deviant social networks.^18,19 The concomitant lack of social order may contribute to low levels of trust, which would impede collaborative efforts to control crime and reduce neighborhood disorder.²⁰ High levels of crime may generate higher levels of fear and stress, as could the deteriorating building conditions and high levels of physical disorder associated with disadvantaged neighborhoods.^20,21 In contexts of social isolation and limited social organization, residents may not benefit from the social networks necessary to buffer them from the stressors they face on a daily basis.²²These theories about the influence of the neighborhood context on collective and individual sources of stress agree with the “differential vulnerability” hypothesis and with social stress theory, both of which posit that environments can influence health by increasing the likelihood of personal stress events such as unemployment or traumatic events, or by providing resources to cope with such stressors.^23–26 Studies using multilevel analytic methods that can account for both individual-level and neighborhood-level effects suggest that neighborhood-level characteristics such as affluence, disadvantage, inequality, and residential stability have a significant impact on physical health, even after accounting for individual-level factors.^27–30 However, research into their possible influence on mental health has been more limited.Cross-sectional studies using multilevel approaches have suggested that symptoms of depression are more prevalent in residents of disadvantaged neighborhoods^31–33 and that this association may be stronger in neighborhoods having less residential turnover^34,35 or higher population density.³⁶ Similar associations have been observed among older adults, for whom living in a neighborhood that is poor or has few elderly people has been associated with higher levels of depressive symptoms, after accounting for individual vulnerabilities.³⁷ The presence of stress-buffering support systems has been associated with lower levels of depression in cross-sectional research, whereas low levels of social support in neighborhoods with high social isolation were related to higher depression levels.^38,39 However, other research has failed to replicate these findings.⁴⁰ Furthermore, the cross-sectional nature of this research means that even positive studies cannot exclude the possibility that the observed relationships simply reflect a tendency for depressed individuals to become disadvantaged or to live in disadvantaged neighborhoods.Longitudinal research can better explore the causal mechanisms behind these relationships, but there have been few prospective studies in this field. A study of individuals who were screened for an HIV prevention intervention found that perceptions of neighborhood characteristics predicted change in depressive symptoms 9 months later.⁴¹ The Alameda County Study found that living in a high-poverty area was associated with worse health status and more symptoms of depression; however, this association was lost when all individual-level covariates were included in multivariable analysis.⁴² In previous research conducted by members of our own team, we identified a significant association between incident depression and neighborhoods classified as low socioeconomic status, even after adjusting for individual income, adverse life events, and educational status.⁴³ This kind of prospective research, although suggestive, has often been weakened by reliance on perceived neighborhood characteristics, limitations of the measures used, or absence of information on possible confounders.To overcome these limitations, we examined the relationship between characteristics of the neighborhood of residence of older adults and symptoms of depression using longitudinal data from the New York City Neighborhood and Mental Health in the Elderly Study (NYCNAMES). We hypothesized that neighborhood socioeconomic status may either exacerbate or ameliorate the stressors confronting participants, thereby influencing levels of depression symptoms over the study period, even after accounting for key individual-level factors. We used information from the 2000 US Census to characterize neighborhoods, and we aggregated these characteristics into dimensions that might shed light on the mechanisms underlying observed relationships.     

The association between perceived discrimination and obesity in a population-based multiracial and multiethnic adult sample

Objectives. We examined whether perceived chronic discrimination was related to excess body fat accumulation in a random, multiethnic, population-based sample of US adults.Methods. We used multivariate multinomial logistic regression and logistic regression analyses to examine the relationship between interpersonal experiences of perceived chronic discrimination and body mass index and high-risk waist circumference.Results. Consistent with other studies, our analyses showed that perceived unfair treatment was associated with increased abdominal obesity. Compared with Irish, Jewish, Polish, and Italian Whites who did not experience perceived chronic discrimination, Irish, Jewish, Polish, and Italian Whites who perceived chronic discrimination were 2 to 6 times more likely to have a high-risk waist circumference. No significant relationship between perceived discrimination and the obesity measures was found among the other Whites, Blacks, or Hispanics.Conclusions. These findings are not completely unsupported. White ethnic groups including Polish, Italians, Jews, and Irish have historically been discriminated against in the United States, and other recent research suggests that they experience higher levels of perceived discrimination than do other Whites and that these experiences adversely affect their health.It is estimated that 2 of every 3 adults in the United States are overweight or obese.^1,2 Obesity is a major risk factor for chronic health conditions, such as type 2 diabetes, coronary heart disease, hypertension, stroke, some forms of cancer, and osteoarthritis.³ Although it is widely accepted that high-fat diets and physical inactivity are preventable risk factors,⁴ obesity continues to increase.^1,2,5There is a growing interest in the relationship between psychosocial risk factors and excess body fat accumulation.^6–16 In particular, some evidence suggests that psychosocial stressors may play a role in disease progression in general and in excess body fat in particular.^7,8,17 The key factors underlying physiological reactions to psychosocial stress have not been completely elucidated, but McEwen and Seeman¹⁷ and others^7,18,19 posit that the continued adaptation of the physiological system to external challenges alters the normal physiological stress reaction pathways and that these changes are related to adverse health outcomes.^8,17,18,20 For example, in examining the association between psychosocial stress and excess body fat accumulation, Björntorp and others have suggested that psychosocial stress is linked to obesity, especially in the abdominal area.^7,8Perceived discrimination, as a psychosocial stressor, is now receiving increased attention in the empirical health literature.^21–24 Such studies suggest perceived discrimination is inversely related to poor mental and physical health outcomes and risk factors, including hypertension,^24,25 depressive symptoms,^26–28 smoking,^29–31 alcohol drinking,^32,33 low birthweight,^34,35 and cardiovascular outcomes.^36–38Internalized racism, the acceptance of negative stereotypes by the stigmatized group,³⁹ has also been recognized as a race-related psychosocial risk factor.⁴⁰ Recent studies have also suggested that race-related beliefs and experiences including perceived discrimination might be potentially related to excess body fat accumulation. Three of these studies^9,13,41 showed that internalized racism was associated with an increased likelihood of overweight or abdominal obesity among Black Caribbean women in Dominica⁴¹ and Barbados¹³ and adolescent girls in Barbados.⁹ These researchers posit that individuals with relatively high levels of internalized racism have adopted a defeatist mindset, which is believed to be related to the physiological pathway associated with excess body fat accumulation. However, Vines et al.¹⁶ found that perceived racism was associated with lower waist-to-hip ratios among Black women in the United States. Although the assessment of race-related risk factors varied across these studies, the findings suggest that the salience of race-related beliefs and experiences may be related to excess body fat accumulation.Collectively, the results of these studies are limited. First, because they examined the relationship between race-related beliefs and experiences and excess body fat only among women, we do not know if this relationship is generalizable to men.^13,16,41 Second, these studies only examined this relationship among Blacks, even though perceived unfair treatment because of race/ethnicity has been shown to be adversely related to the health of multiple racial/ethnic population groups in the United States^42–49 and internationally.^27,50–55 Third, none of the studies have examined the relationship between excess body fat accumulation and perceived nonracial/nonethnic experiences of interpersonal discrimination. Some evidence suggests that the generic perception of unfair treatment or bias is adversely related to health, regardless of whether it is attributed to race, ethnicity, or some other reason.^45,55,56 Fourth, none of these studies included other measures of stress. We do not know if the association between race-related risk factors and obesity is independent of other traditional indicators of stress.Using a multiethnic, population-based sample of adults, we examined the association of perceived discrimination and obesity independent of other known risk factors for obesity, including stressful major life events. Additionally, because reports of perceived racial/ethnic discrimination and non-racial/ethnic discrimination vary by racial/ethnic groups^24,45,46,57 and because Whites tend to have less excess body fat than do Blacks and Hispanics,^1,3 we examined the relationships between perceived discrimination and excess body fat accumulation among Hispanics, non-Hispanic Whites, and non-Hispanic Blacks.     

A nationwide analysis of US racial/ethnic disparities in smoking behaviors, smoking cessation, and cessation-related factors

Objectives. We used nationally representative data to examine racial/ethnic disparities in smoking behaviors, smoking cessation, and factors associated with cessation among US adults.Methods. We analyzed data on adults aged 20 to 64 years from the 2003 Tobacco Use Supplement to the Current Population Survey, and we examined associations by fitting adjusted logistic regression models to the data.Results. Compared with non-Hispanic Whites, smaller proportions of African Americans, Asian Americans/Pacific Islanders, and Hispanics/Latinos had ever smoked. Significantly fewer African Americans reported long-term quitting. Racial/ethnic minorities were more likely to be light and intermittent smokers and less likely to smoke within 30 minutes of waking. Adjusted models revealed that racial/ethnic minorities were not less likely to receive advice from health professionals to quit smoking, but they were less likely to use nicotine replacement therapy.Conclusions. Specific needs and ideal program focuses for cessation may vary across racial/ethnic groups, such that approaches tailored by race/ethnicity might be optimal. Traditional conceptualizations of cigarette addiction and the quitting process may need to be revised for racial/ethnic minority smokers.Racial/ethnic minorities in the United States experience a disproportionate burden of smoking-related diseases, including cancer and heart disease, despite having larger proportions of light and intermittent smokers and generally lower adult smoking prevalence rates than non-Hispanic Whites.^1–3 Racial/ethnic minorities are also less likely to quit smoking successfully than are non-Hispanic Whites.^4–8 For example, rates of successful smoking cessation among African American smokers are lower than they are among non-Hispanic Whites, despite reports citing lower cigarette consumption.^2,5,7,9 Similarly, Hispanics/Latinos do not experience higher rates of successful quitting than non-Hispanic Whites, despite being more likely to be light and intermittent smokers.^2,9 There is currently no evidence indicating that Asian Americans quit at higher rates than non-Hispanic Whites in the United States.¹⁰ The examination of racial/ethnic disparities in smoking behaviors, successful quitting, and factors associated with quitting can provide valuable information for focusing strategies for groups currently experiencing lower rates of successful smoking cessation, and can lead to decreases in smoking-related disease rates across all racial/ethnic populations.Previous research on population-level data has found several factors to be associated with successful smoking cessation. For example, banning smoking in one''s home can greatly increase the chances of successfully quitting smoking. The presence of a complete ban on smoking in one''s home is associated with being quit for at least 90 days¹¹ and with being a former smoker.¹² However, an analysis of national data found that smaller percentages of non-Hispanic Whites (64.0%) and African Americans (64.4%) have a complete home smoking ban than do Hispanics/Latinos (78.0%) and Asian Americans/Pacific Islanders (79.2%).¹³ Being advised to quit smoking by health care professionals, especially physicians, has also been associated with increased rates of smoking cessation.^14–17 Despite progress in smokers being advised to quit by health care practitioners in the past 5 years, African American and Hispanic/Latino smokers remain less likely than non-Hispanic Whites to be advised to quit.^16,18 Finally, although evidence of the effectiveness of nicotine replacement therapy (NRT) at the population level has been challenged recently,^19,20 there is evidence that NRT can aid successful cessation.^17,21–23 There is substantial evidence that racial/ethnic minorities are less likely to be prescribed NRT^14,15,18 and to use NRT to quit smoking.^23–25The Tobacco Use Supplements to the Current Population Surveys (TUS-CPS) have provided invaluable data for the examination of various smoking-related issues at the national level.^11,13 In 2003, the TUS-CPS included a special supplement that focused heavily on smoking cessation. This supplement was the first TUS-CPS with this focus (and is the only one to date), and it provides arguably the richest representative national-level data on smoking cessation in the United States. This special supplement thus presented a unique opportunity to examine in detail the disparities between racial/ethnic groups in smoking cessation and important related factors.For our study, we hypothesized the following: (1) African Americans would experience less success in quitting smoking than would non-Hispanic Whites, (2) Asian Americans/Pacific Islanders and Hispanics/Latinos would be more likely to have a complete home smoking ban than would non-Hispanic Whites, (3) African Americans and Hispanics/Latinos would be less likely than would non-Hispanic Whites to report being advised by a health professional to quit smoking, and (4) racial/ethnic minorities would be less likely to use NRT than would non-Hispanic Whites.To examine these hypotheses, we conducted a secondary data analysis of the 2003 TUS-CPS to assess smoking cessation rates and examine how factors associated with successful smoking cessation differed across racial/ethnic groups among adults in the United States. Findings from this report may provide insight into optimal design of targeted smoking cessation interventions for members of specific racial/ethnic groups.     

Neighborhood Context and Infant Birthweight Among Recent Immigrant Mothers: A Multilevel Analysis

Objectives. We compared the influence of the residential environment and maternal country of origin on birthweight and low birthweight of infants born to recent immigrants to urban Ontario.Methods. We linked delivery records (1993–2000) to an immigration database (1993–1995) and small-area census data (1996). The data were analyzed with cross-classified random-effects models and standard multilevel methods. Higher-level predictors included 4 independent measures of neighborhood context constructed by factor analysis and maternal world regions of origin.Results. Births (N = 22 189) were distributed across 1396 census tracts and 155 countries of origin. The associations between neighborhood indices and birthweight disappeared after we controlled for the maternal country of origin in a cross-classified multilevel model. Significant associations between world regions and birthweight and low birthweight persisted after we controlled for neighborhood context and individual characteristics.Conclusions. The residential environment has little, if any, influence on birthweight among recent immigrants to Ontario. Country of origin appears to be a much more important factor in low birthweight among children of recent immigrants than current neighborhood. Findings of neighborhood influences among recent immigrants should be interpreted with caution.Socioeconomic disparities in birth outcomes are well documented,^1–3 even in countries with universal access to health care,^4,5 such as Canada. An increasing body of literature, including several multilevel studies, suggests that context affects birth outcomes, particularly neighborhood influences in predominantly urban areas.^6–16 Little is known, however, about neighborhood influences among immigrants.^15,17–19There are theoretical and practical reasons to explore this issue. It has been suggested that exposure to neighborhoods may take some time to affect human health.²⁰ Even if neighborhood influences are detected among the offspring of recent immigrant women exposed to neighborhoods during their entire pregnancy, a life-course perspective suggests that early life experiences and premigration exposures may still affect birth outcomes of migrants in the new country.^19,21 The maternal country of origin thus constitutes another relevant context to be considered when analyzing differences in birthweight among recent immigrants, because substantial differences in birthweight have been reported by geographical region and nativity status.^22–24 It is important to clarify the role of the pre- and postmigration exposures, because the proportion of live births to immigrant women has been showing an upward trend during recent decades in several industrialized countries.^24–27We compared the influence of the residential environment at the time of delivery with that of the maternal country of origin on birthweight and the proportion of low birthweights among infants born to women who recently immigrated to Canada and settled in Ontario census metropolitan areas from 1993 to 1995. We hypothesized that the maternal country of origin would have a greater effect on birthweight than would the residential environment in which immigrants currently resided in urban Ontario.     

The California Endowment's Healthy Eating, Active Communities Program: A Midpoint Review

Objectives. We conducted a midpoint review of The California Endowment''s Healthy Eating, Active Communities (HEAC) program, which works in 6 low-income California communities to prevent childhood obesity by changing children''s environments. The HEAC program conducts interventions in 5 key childhood environments: schools, after-school programs, neighborhoods, health care, and marketing and advertising.Methods. We measured changes in foods and beverages sold at schools and in neighborhoods in HEAC sites; changes in school and after-school physical activity programming and equipment; individual-level changes in children''s attitudes and behaviors related to food and physical activity; and HEAC-related awareness and engagement on the part of community members, stakeholders, and policymakers.Results. Children''s environments changed to promote healthier lifestyles across a wide range of domains in all 5 key childhood environments for all 6 HEAC communities. Children in HEAC communities are also engaging in more healthy behaviors than they were before the program''s implementation.Conclusions. HEAC sites successfully changed children''s food and physical activity environments, making a healthy lifestyle a more viable option for low-income children and their families.Childhood obesity is at epidemic levels in the United States. More than 1 in 7 children and adolescents aged 6 to 17 years are considered obese.¹ Additionally, disparities in obesity rates exist among ethnic groups. Black, Hispanic, and Native American children and adolescents have higher rates of diabetes and obesity than do White children and adolescents.¹ Poor diet and inadequate physical activity have been linked to obesity and preventable chronic illnesses.^2,3 Overweight and obese children may develop a number of risk factors for chronic disease and are increasingly diagnosed with diseases that have historically had their onset in adulthood, such as type 2 diabetes, hypertension, and high cholesterol.⁴Most strategies to prevent or reduce childhood obesity have focused on individual behavior modification and pharmacological treatment, with limited success.⁵ Current research suggests that childhood dietary habits and physical activity levels are influenced by a variety of environmental factors,⁶ such as increasing portion sizes,^7–10 increasing availability of fast food and soft drinks,^11–20 availability of soda and unhealthy food on school campuses,^21–29 curtailment or elimination of physical education and recess in schools,³⁰ insufficient or inadequate parks and recreational facilities,³¹ public policy favoring personal transportation over mass transit,^32–39 limited access to healthy foods and ready availability of unhealthy foods,^37,40–44 and disproportionate advertising of low-nutrient-dense foods and sedentary activities to children and their families.^25,45–49Many of these factors are exacerbated in low-income communities, where healthy and affordable food options and safe opportunities for physical activity are noticeably absent.^40,42 These factors are contributing to high levels of diseases related to nutrition and physical activity among Black and Latino populations.^34,40,42,50A better understanding of the underlying factors that lead to obesity has led to the emergence of a new type of initiative that seeks to reduce childhood obesity by making environmental improvements that promote healthy eating and physical activity, rather than focusing on changing individual eating and activity patterns. Although this type of environmental intervention is relatively new, early results are encouraging.^51–53 It has been demonstrated that better access to healthy foods and opportunities for physical activity results in healthier diets and increased physical activity: people in the presence of supermarkets eat more fruits and vegetables,^40,42,54 and when a venue for physical activity is available, people are more likely to be physically active.^34,55To help prevent obesity and type 2 diabetes among children and adolescents, the Healthy Eating, Active Communities (HEAC) program was established to promote public health environmental change in 6 California communities. We conducted a midpoint review of HEAC''s progress to assess how well these communities were translating models for change into on-the-ground practices resulting in real improvements in the food and physical activity opportunities available to low-income children and families.     

Racial/Ethnic and Socioeconomic Differences in Short-Term Breast Cancer Survival Among Women in an Integrated Health System

Objectives. We examined the combined influence of race/ethnicity and neighborhood socioeconomic status (SES) on short-term survival among women with uniform access to health care and treatment.Methods. Using electronic medical records data from Kaiser Permanente Northern California linked to data from the California Cancer Registry, we included 6262 women newly diagnosed with invasive breast cancer. We analyzed survival using multivariable Cox proportional hazards regression with follow-up through 2010.Results. After consideration of tumor stage, subtype, comorbidity, and type of treatment received, non-Hispanic White women living in low-SES neighborhoods (hazard ratio [HR] = 1.28; 95% confidence interval [CI] = 1.07, 1.52) and African Americans regardless of neighborhood SES (high SES: HR = 1.44; 95% CI = 1.01, 2.07; low SES: HR = 1.88; 95% CI = 1.42, 2.50) had worse overall survival than did non-Hispanic White women living in high-SES neighborhoods. Results were similar for breast cancer–specific survival, except that African Americans and non-Hispanic Whites living in high-SES neighborhoods had similar survival.Conclusions. Strategies to address the underlying factors that may influence treatment intensity and adherence, such as comorbidities and logistical barriers, should be targeted at low-SES non-Hispanic White and all African American patients.Breast cancer is the most common cancer among women in the United States, and it is the second leading cause of cancer death.1 Despite significant improvements in breast cancer survival from 1992 to 2009,1,2 racial/ethnic and socioeconomic survival disparities have persisted.3,4 African American women have consistently been found to have worse survival after breast cancer,3,5–11 Hispanic women have worse or similar survival,3,9,11,12 and Asian women as an aggregated group have better or similar survival3,9,11,12 than do non-Hispanic White women. Underlying factors thought to contribute to these racial/ethnic disparities include differences in stage at diagnosis,8,12,13 distributions of breast cancer subtypes,14–16 comorbidities,12,13,17 access to and utilization of quality care,13,18 and treatment.12,13Numerous studies also have found poorer survival after breast cancer diagnosis among women residing in neighborhoods of lower socioeconomic status (SES).6,9,19,20 Research has shown that inadequate use of cancer screening services, and consequent late stage diagnosis and decreased survival, contribute to the SES disparities.21,22 Similar to racial/ethnic disparities, SES disparities have been attributed to inadequate treatment and follow-up care and comorbidities.18 Previous population-based studies have continued to observe racial/ethnic survival disparities after adjusting for neighborhood SES, but these studies have not considered the combined influence of neighborhood SES and race/ethnicity.3,9,11,12,23 These disparities may remain because information on individual-level SES, health insurance coverage, comorbidities, quality of care, and detailed treatment regimens have typically not been available.3,8,9,11,13 Even among studies using national Surveillance Epidemiology and End Results–Medicare linked data, in which more detailed information on treatment and comorbidities are available among some patients aged 65 years and older, survival disparities have remained.12,23,24 However, not all data on medical conditions and health care services are captured in Medicare claims, including data on Medicare beneficiaries enrolled in HMOs (health maintenance organizations).25,26Using electronic medical records data from Kaiser Permanente Northern California (KPNC) linked to data from the population-based California Cancer Registry (CCR), we recently reported that chemotherapy use followed practice guidelines but varied by race/ethnicity and neighborhood SES in this integrated health system.27 Therefore, to overcome the limitations of previous studies and address simultaneously the multiple social28 and clinical factors affecting survival after breast cancer diagnosis, we used the linked KPNC–CCR database to determine whether racial/ethnic and socioeconomic differences in short-term overall and breast cancer–specific survival persist in women in a membership-based health system. Our study is the first, to our knowledge, to consider the combined influence of neighborhood SES and race/ethnicity and numerous prognostic factors, including breast cancer subtypes and comorbidities, thought to underlie these long-standing survival disparities among women with uniform access to health care and treatment.     

Association of Perceived Neighborhood Safety on Body Mass Index

Objectives. We sought to determine whether there is an association between perceived neighborhood safety and body mass index (BMI), accounting for endogeneity.Methods. A random sample of 2255 adults from the Los Angeles Family and Neighborhood Survey 2000–2001 was analyzed using instrumental variables. The main outcome was BMI using self-reported height and weight, and the main independent variable was residents’ report of their neighborhood safety.Results. In adjusted analyses, individuals who perceived their neighborhoods as unsafe had a BMI that was 2.81 kg/m² (95% confidence interval [CI] = 0.11, 5.52) higher than did those who perceived their neighborhoods as safe.Conclusions. Our results suggest that clinical and public health interventions aimed at reducing rates of obesity may be enhanced by strategies to modify the physical and social environment that incorporate residents’ perceptions of their communities.Obesity is a major public health problem^1–5 that contributes to poor quality of life; increased incidence of diabetes, cardiovascular disease, and other chronic conditions; and higher mortality rates.⁵ During the last decade, population-based strategies to reduce obesity have emphasized modification of physical and social environments, which may be particularly important in disadvantaged communities. Low neighborhood socioeconomic status (SES),⁶ a higher proportion of Black and Latino residents,^7–10 barriers in the built environment (e.g., fewer places to walk),^11,12 lack of access to supermarkets or fresh fruits and vegetables,^6,13,14 and a higher density of fast food restaurants¹⁵ are all characteristics of residential environments associated with obesity. Research also suggests that low levels of collective efficacy (a perception of mutual trust and willingness to help each other)¹⁶ are associated with adolescent obesity. However, the mechanisms through which neighborhood social, economic, and physical characteristics lead to weight gain and obesity are not well characterized.Perceived neighborhood safety is a mechanism through which neighborhood characteristics may influence obesity. Residence in a neighborhood perceived as unsafe may contribute to obesity in a number of ways, including increased secretion of stress hormones,^17–19 lower rates of walking or other outdoor physical activity,^20–28 and higher rates of stress-related eating.^29–32 Perceived safety may reflect the physical, social, and resource characteristics of neighborhoods. For example, residents may perceive a neighborhood to be unsafe if supermarkets and retailers that sell fresh fruits and vegetables are unwilling to locate in their neighborhoods, or if fast food restaurants and stores that sell low-cost, calorie-dense foods tend to locate in their neighborhoods.^33–35 Yet, the limited literature on relations between perceived safety and body weight is mixed. One study found that mothers with young children, residing in large cities, and perceiving their neighborhoods as unsafe were more likely to be obese,³⁶ and another study found no association between perceived safety and obesity.³⁷ Similarly, in the larger body of literature on neighborhood safety and physical activity, some studies found an association of perceived neighborhood safety with physical activity levels,^20–26 although other analyses showed no such relationship,^38–42 suggesting a more complex etiology.We hypothesized that 1 reason for the inconsistent findings in these previous analyses—all of which were cross-sectional—is endogeneity bias, that is, the possibility that the findings from these studies may have been influenced by either reverse causality^36,43 or unmeasured neighborhood or individual characteristics influencing both perceived neighborhood safety and obesity. For example, reverse causality may occur if larger individuals, believing nobody would attack them because of their size, feel safer, or if larger individuals, being less agile and less physically fit and believing they cannot protect themselves, feel less safe. To address the possibility of endogeneity from reverse causality or unmeasured neighborhood or individual characteristics, we studied the association between perceived neighborhood safety and obesity in a population-based, geographically sampled cohort of residents in Los Angeles County, California. We used 2-stage least squares regression, a special case of an instrumental variables analysis that is a method developed to produce statistically consistent estimates when the covariate of interest is potentially endogenous. To our knowledge, no studies to date have used instrumental variables analysis to assess the relationship between neighborhood safety and obesity.     

The Long-Term Health Consequences of Relationship Violence in Adulthood: An Examination of Low-Income Women From Boston, Chicago, and San Antonio

Objectives. We examined the long-term health consequences of relationship violence in adulthood.Methods. Using data from the Welfare, Children, and Families project (1999 and 2001), a probability sample of 2402 low-income women with children living in disadvantaged neighborhoods in Boston, Massachusetts; Chicago, Illinois; and San Antonio, Texas, we predicted changes in the frequency of intoxication, psychological distress, and self-rated health over 2 years with baseline measures of relationship violence and a host of relevant background variables.Results. Our analyses showed that psychological aggression predicted increases in psychological distress, whereas minor physical assault and sexual coercion predicted increases in the frequency of intoxication. There was no evidence to suggest that relationship violence in adulthood predicted changes in self-rated health.Conclusions. Experiences with relationship violence beyond the formative and developmental years of childhood and adolescence can have far-reaching effects on the health status of disadvantaged urban women.Over the past 2 decades, numerous studies have examined the long-term health consequences of relationship violence during childhood. This body of research suggests that physical and sexual abuse in early life can be devastating to health in adulthood, contributing to poor mental^1–6 and physical health^3–5,7 and to higher rates of substance abuse.^5,6,8,9 These patterns are remarkably consistent across studies and notably persistent through the life course. In a recent study of more than 21 000 older adults, Draper et al.³ reported that physical and sexual abuse before 15 years of age is associated with poor mental and physical health well into late life.Although previous research has made significant contributions to our understanding of the lasting effects of abuse in early life, few studies have considered the long-term health consequences of relationship violence in adulthood. Our review of the literature revealed 5 longitudinal studies of relationship violence and health in adulthood. Not surprisingly, research suggests that women who experience relationship violence in adulthood are vulnerable to poor health trajectories, including increases in depressive symptoms,^10–12 functional impairment,^10,12 and alcohol consumption.^13,14Relationship violence is an important issue in all segments of society; however, studies consistently show that women of low socioeconomic status exhibit higher rates of intimate partner victimization than do their more affluent counterparts.^15–17 For example, Tolman and Raphael¹⁷ reported that between 34% and 65% of women receiving welfare report having experienced some form of relationship violence in their lifetime, and between 8% and 33% experience some form of relationship violence each year, levels that surpass those for women overall.¹⁸ Research also shows that residence in disadvantaged neighborhoods^19,20 and the presence of children in the household^21,22 may elevate the odds of relationship violence. Given their high violence-risk profile, attention must be directed to the patterns and health consequences of intimate partner victimization in the lives of disadvantaged urban women with children.^23–25Building on previous research, we used data collected from a large probability sample of low-income women with children living in low-income neighborhoods in Boston, Massachusetts, Chicago, Illinois, and San Antonio, Texas, to predict changes in the frequency of intoxication, psychological distress, and self-rated health over 2 years with measures of relationship violence in early life and adulthood and a host of relevant background variables. In accordance with previous research, we expected that intimate partner victimization in adulthood would predict increases in psychological distress and the frequency of intoxication and decreases in self-rated health over the study period.     

Walking and Cycling to Health: A Comparative Analysis of City, State, and International Data

Objectives. We sought to determine the magnitude, direction, and statistical significance of the relationship between active travel and rates of physical activity, obesity, and diabetes.Methods. We examined aggregate cross-sectional health and travel data for 14 countries, all 50 US states, and 47 of the 50 largest US cities through graphical, correlation, and bivariate regression analysis on the country, state, and city levels.Results. At all 3 geographic levels, we found statistically significant negative relationships between active travel and self-reported obesity. At the state and city levels, we found statistically significant positive relationships between active travel and physical activity and statistically significant negative relationships between active travel and diabetes.Conclusions. Together with many other studies, our analysis provides evidence of the population-level health benefits of active travel. Policies on transport, land-use, and urban development should be designed to encourage walking and cycling for daily travel.Many nations throughout the world have experienced large increases in obesity rates over the past 30 years.^1,2 The World Health Organization estimates that more than 300 million adults are obese,³ putting them at increased risk for diseases such as diabetes, hypertension, cardiovascular disease, gout, gallstones, fatty liver, and some cancers.^4,5 Several studies have linked the increase in obesity rates to physical inactivity^6–8 and to widespread availability of inexpensive, calorie-dense foods and beverages.^1,9The importance of physical activity for public health is well established. A US Surgeon General''s report in 1996, Physical Activity and Health,¹⁰ summarized evidence from cross-sectional studies; prospective, longitudinal studies; and clinical investigations. The report concluded that physical inactivity contributes to increased risk of many chronic diseases and health conditions. Furthermore, the research suggested that even 30 minutes per day of moderate-intensity physical activity, if performed regularly, provides significant health benefits. Subsequent reports have supported these conclusions.^11–13The role of physical activity in prevention of weight gain is well documented.¹⁴ Strong evidence from cross-sectional studies has established an inverse relationship between physical activity and body mass index.^15,16 In addition, longitudinal studies have shown that exercisers gain less weight than do their sedentary counterparts.^6,8 Thus, the obesity epidemic may be explained partly by declining levels of physical activity.^1,17,18A growing body of evidence suggests that differences in the built environment for physical activity (e.g., infrastructure for walking and cycling, availability of public transit, street connectivity, housing density, and mixed land use) influence the likelihood that people will use active transport for their daily travel.^19,20 People who live in areas that are more conducive to walking and cycling are more likely to engage in these forms of active transport.^21–25 Walking and cycling can provide valuable daily physical activity.^26–30 Such activities increase rates of caloric expenditure,³¹ and they generally fall into the moderate-intensity range that provides health benefits.^32–35 Thus, travel behavior could have a major influence on health and longevity.^29,30,36,37Over the past decade, researchers have begun to identify linkages between active travel and public health.^38–40 Cross-sectional studies indicate that walking and cycling for transport are linked to better health. The degree of reliance on walking and cycling for daily travel differs greatly among countries.^39,41 European countries with high rates of walking and cycling have less obesity than do Australia and countries in North America that are highly car dependent.²⁶ In addition, walking and cycling for transport are directly related to improved health in older adults.⁴² The Coronary Artery Risk Development in Young Adults Study found that active commuting was positively associated with aerobic fitness among men and women and inversely associated with body mass index, obesity, triglyceride levels, resting blood pressure, and fasting insulin among men.^26,39,41,43Further evidence of the link between active commuting and health comes from prospective, longitudinal studies.⁴⁴ Matthews et al. examined more than 67 000 Chinese women in the Shanghai women''s health study and followed them for an average of 5.7 years.³⁷ Women who walked (P < .07) and cycled (P < .05) for transport had lower rates of all-cause mortality than did those who did not engage in such behaviors. Similarly, Andersen et al. observed that cycling to work decreased mortality rates by 40% among Danish men and women.³⁶ A recent analysis of a multifaceted cycling demonstration project in Odense, Denmark, reported a 20% increase in cycling levels from 1996 to 2002 and a 5-month increase in life expectancy for males.⁴⁵We analyzed recent evidence from a variety of data sources that supports the crucial relationship between active travel, physical activity, obesity, and diabetes. We used city- and state-level data from the United States and national aggregate data for 14 countries to determine the magnitude, direction, and statistical significance of each relationship.     

Health Among Caregivers of Children With Health Problems: Findings From a Canadian Population-Based Study

Objectives. We used population-based data to evaluate whether caring for a child with health problems had implications for caregiver health after we controlled for relevant covariates.Methods. We used data on 9401 children and their caregivers from a population-based Canadian study. We performed analyses to compare 3633 healthy children with 2485 children with health problems. Caregiver health outcomes included chronic conditions, activity limitations, self-reported general health, depressive symptoms, social support, family functioning, and marital satisfaction. Covariates included family (single-parent status, number of children, income adequacy), caregiver (gender, age, education, smoking status, biological relationship to child), and child (age, gender) characteristics.Results. Logistic regression showed that caregivers of children with health problems had more than twice the odds of reporting chronic conditions, activity limitations, and elevated depressive symptoms, and had greater odds of reporting poorer general health than did caregivers of healthy children.Conclusions. Caregivers of children with health problems had substantially greater odds of health problems than did caregivers of healthy children. The findings are consistent with the movement toward family-centered services recognizing the link between caregivers'' health and health of the children for whom they care.Caring for a child with health problems can entail greater than average time demands,^1,2 medical costs,^3,4 employment constraints,^5,6 and childcare challenges.^6–8 These demands may affect the health of caregivers, a notion supported by a variety of small-scale observational studies that have shown increased levels of stress, distress, emotional problems, and depression among caregivers of children with health problems.^1,2,5,9–12Whether these problems are caused by the additional demands of caring for children with health problems or by confounding variables is difficult to answer definitively. The literature reports the identification of a variety of factors purported to be associated with caregiver health, including contextual factors such as socioeconomic status^13–17; child factors such as level of disability,^{1,11,13,18–21} presence of behavior problems,^22–25 and overall child adjustment²⁶; and caregiver-related characteristics such as coping strategies^11,22,27 and support from friends and family.^15,17,28,29 In general, this work has been based on small clinic-based samples^9,30 or specific child populations (e.g., cerebral palsy,^5,25 attention-deficit/hyperactivity disorder^31,32), and typically has been hampered by limited generalizability and a lack of careful, multivariate analysis. Furthermore, most studies have focused on caregivers'' psychological health,^1,2,5,9–12 although physical health effects may also exist among caregivers.^5,19,25,33One of the few studies to involve large-scale, population-based data compared the health of 468 caregivers of children with cerebral palsy to the health of a population-based sample of Canadian parents.⁵ The study showed that caregivers of children with cerebral palsy had poorer health on a variety of physical and psychological health measures. Furthermore, the data were consistent with a stress process model,^5,25 which proposes that additional stresses associated with caring for a child with cerebral palsy directly contribute to poorer caregiver health. However, these findings were based on a specific subpopulation of caregivers and univariate comparisons that could not control for potentially important confounders such as variation in caregiver education, income, and other demographic factors.We used population-based data to test the hypothesis that the health of caregivers of children with health problems would be significantly poorer than that of caregivers of healthy children, even after we controlled for relevant covariates. Our approach of using large-scale, population-based data representing a broad spectrum of childhood health problems³⁴ makes 4 key contributions to the current literature. First, our use of population-based data rather than small-scale, clinic-based studies yielded results that are potentially generalizable to a wide group of caregivers caring for children with health problems. Second, our examination of children with and without health problems allowed us to examine caregiver health effects across a wide variety of caregiving situations. Third, consideration of physical health outcomes (in addition to more regularly studied psychological outcomes) increased our knowledge of the breadth of caregiver health issues. Finally, controlling for relevant covariates allowed us to rule out a number of alternative explanations for caregiver health effects.     

Policy Support, Norms, and Secondhand Smoke Exposure Before and After Implementation of a Comprehensive Smoke-Free Law in Mexico City

Objectives. We assessed attitudes and beliefs about smoke-free laws, compliance, and secondhand smoke exposure before and after implementation of a comprehensive smoke-free law in Mexico City.Methods. Trends and odds of change in attitudes and beliefs were analyzed across 3 representative surveys of Mexico City inhabitants: before implementation of the policy (n = 800), 4 months after implementation (n = 961), and 8 months after implementation (n = 761).Results. Results indicated high and increasing support for 100% smoke-free policies, although support did not increase for smoke-free bars. Agreement that such policies improved health and reinforced rights was high before policy implementation and increased thereafter. Social unacceptability of smoking increased substantially, although 25% of nonsmokers and 50% of smokers agreed with smokers'' rights to smoke in public places at the final survey wave. Secondhand smoke exposure declined generally as well as in venues covered by the law, although compliance was incomplete, especially in bars.Conclusions. Comprehensive smoke-free legislation in Mexico City has been relatively successful, with changes in perceptions and behavior consistent with those revealed by studies conducted in high-income countries. Normative changes may prime populations for additional tobacco control interventions.Smoke-free policies can reduce involuntary exposure to toxic secondhand tobacco smoke (SHS), reduce tobacco consumption and promote quitting,^1,2 and shift social norms against smoking.^3–5 These policies are fundamental to the World Health Organization''s Framework Convention on Tobacco Control, an international treaty that promotes best-practices tobacco control policies across the world.⁶Evidence of successful implementation of smoke-free policies generally comes from high-income countries. Low- and middle-income countries increasingly bear the burden of tobacco use,⁷ however, and these countries may face particular challenges in implementing smoke-free policies, including greater social acceptability of tobacco use, shorter histories of programs and policies to combat tobacco-related dangers, and greater tolerance of law breaking.^8–10 There is a need for research that will help identify effective strategies for promoting and implementing smoke-free policies in low- and middle-income countries.Studies in high-income countries generally indicate that popular support for laws that ban smoking in public places and workplaces is strong and increases after such laws are passed.^11–15 Weaker laws that allow smoking in some workplaces can leave policy support unchanged.¹⁶ Policy-associated increases in support have been shown across populations that include smokers^{11,13,14,17,18} and bar owners and staff.^19,20 Beliefs about rights to work in smoke-free environments¹¹ and the health benefits of these environments²¹ have also been shown to increase with policy implementation. Support for banning smoking in all workplaces appears high in Latin American countries,²² but responses to smoke-free policies are less well known. In Uruguay, the first country in the Americas to prohibit smoking in all workplaces, including restaurants and bars,²³ support before the law was unknown. However, the level of support was high among both the general population²² and smokers²⁴ after the law''s implementation.Compliance with smoke-free laws in high-income countries has been good, particularly when laws apply across all workplaces, including restaurants and bars, and involve media campaigns. Self-reported declines in exposure in regulated venues^11,17,25 are consistent with findings from observational studies,^11,26 biomarkers of exposure,^11,25,27 and air quality assessments.^11,12Approximately 26% of Mexican adults residing in urban areas smoke.⁸ Most Mexicans recognize the harms of SHS and support smoke-free policies.^9,24,28,29 According to an opinion poll conducted before the August 2007 passage of a smoke-free law in Mexico City, about 80% of both Mexico City inhabitants and Mexicans in general supported prohibiting smoking in enclosed public places and workplaces.²⁸ In 2006, 60% of smokers reported that their workplace had a smoking ban, with Mexico City smokers reporting the lowest percentage of workplace bans at 37%.²⁴Mexico City''s smoke-free workplace law^30–32 initially allowed for designated smoking areas that were ventilated and physically separate.^22,33 Concerns about the inequity of this law for small business owners who could not afford to build designated smoking areas led the hospitality industry to support a comprehensive smoke-free law^31,32 that prohibited smoking inside all enclosed public places and workplaces, including public transport, restaurants, and bars. This law entered into force on April 3, 2008.Media coverage of the law was similar to that in high-income countries, pitting arguments about the government''s obligation to protect citizens from SHS dangers against arguments about discrimination toward smokers and the “slippery slope” of regulating behavior^4,32,34 (J. F. Thrasher et al., unpublished data, 2010). Most print media coverage was either positive or neutral, with much less coverage pitched against tobacco control policies.³⁴In the month before and after the law came into effect, the Mexico City Ministry of Health and nongovernmental organizations disseminated print materials and aired radio spots describing the dangers of SHS and the benefits of the law.³⁰ Community health promoters informed businesses about the law. From September through December 2008, a television, radio, print, and billboard campaign emphasized the law''s benefits.³⁵ We assessed, among Mexico City inhabitants, the prevalence of and increases in support, beliefs, norms, and compliance around the smoke-free law, as well as decreases in SHS exposure.     

Reinforcement of smoking and drinking: tobacco marketing strategies linked with alcohol in the United States

Objectives. We investigated tobacco companies’ knowledge about concurrent use of tobacco and alcohol, their marketing strategies linking cigarettes with alcohol, and the benefits tobacco companies sought from these marketing activities.Methods. We performed systematic searches on previously secret tobacco industry documents, and we summarized the themes and contexts of relevant search results.Results. Tobacco company research confirmed the association between tobacco use and alcohol use. Tobacco companies explored promotional strategies linking cigarettes and alcohol, such as jointly sponsoring special events with alcohol companies to lower the cost of sponsorships, increase consumer appeal, reinforce brand identity, and generate increased cigarette sales. They also pursued promotions that tied cigarette sales to alcohol purchases, and cigarette promotional events frequently featured alcohol discounts or encouraged alcohol use.Conclusions. Tobacco companies’ numerous marketing strategies linking cigarettes with alcohol may have reinforced the use of both substances. Because using tobacco and alcohol together makes it harder to quit smoking, policies prohibiting tobacco sales and promotion in establishments where alcohol is served and sold might mitigate this effect. Smoking cessation programs should address the effect that alcohol consumption has on tobacco use.Smoking remains the leading preventable cause of premature mortality in the United States, accounting for more than 440 000 deaths annually.¹ Alcohol consumption is the third-leading cause of mortality in the nation.² Each year, approximately 79 000 deaths are attributable to excessive alcohol use.³ The concurrent use of cigarettes and alcohol further increases risks for certain cancers, such as cancer of the mouth, throat, and esophagus.^4,5 In addition, the use of both tobacco and alcohol makes it more difficult to quit either substance.⁶Smoking and drinking are strongly associated behaviors.^7–13 Smokers are more likely to drink alcohol,¹¹ drink more frequently,^8,11 consume a higher quantity of alcohol,^8,11,14 and demonstrate binge drinking (5 or more drinks per episode) than are nonsmokers.^9,11,12 Alcohol drinkers, especially binge drinkers, are also more likely to smoke^7,8,10 and are more likely to smoke half a pack of cigarettes or more per day.¹⁰The association between tobacco use and alcohol use becomes stronger with the heavier use of either substance.^8,15,16 Alcohol consumption increases the desire to smoke,^17,18 and nicotine consumption increases alcohol consumption.¹⁹ Experimental studies have demonstrated that nicotine and alcohol enhance each other''s rewarding effects.^16,18 Alcohol increases the positive subjective effects of smoking,^8,15,16,20 and smoking while using alcohol is more reinforcing than is smoking without concurrent alcohol use.⁸ Smokers smoke more cigarettes while drinking alcohol,^8,15,18 especially during binge-drinking episodes.^8,15 This behavior has also been observed among nondaily smokers^8,15 and light smokers.¹⁷The concurrent use of alcohol and tobacco is common among young adults,^8,10,12,21 including nondaily smokers,^19,22–24 nondependent smokers,⁸ and novice smokers.¹³ Young adult smokers have reported that alcohol increases their enjoyment of and desire for cigarettes^8,25 and that tobacco enhances the effect of alcohol: it “brings on the buzz” or “gave you a double buzz.”^13,23,26 Young adult nondaily smokers described the pairing of alcohol and cigarettes as resembling “milk and cookies” or “peanut butter with jelly.”²⁴ Young adults have also been the focus of aggressive tobacco promotional efforts in places where alcohol is consumed, such as bars and nightclubs.^27,28Consumer products often fall into cohesive groups (sometimes referred to as “Diderot unities”) that may reinforce certain patterns of consumption,²⁹ and these groupings may be influenced by marketing activities. In the case of tobacco and alcohol, these product links may have been further enhanced by cooperation between tobacco and alcohol companies (e.g., cosponsorship) or corporate ownership of both tobacco and alcohol companies (e.g., Philip Morris''s past ownership of Miller Brewing Company).We used tobacco industry documents to explore tobacco companies’ knowledge regarding linked tobacco and alcohol use and the companies’ marketing strategies that linked cigarettes with alcohol. We were interested in 3 basic issues: (1) what tobacco companies knew about the association between drinking and smoking, especially about smokers’ drinking behaviors, (2) how tobacco and alcohol companies developed cross promotions featuring cigarettes and alcohol, and (3) how tobacco companies linked cigarettes with alcohol in their marketing activities and the benefits they expected to gain from those activities.     

Racial Residential Segregation and Rates of Gonorrhea in the United States, 2003–2007

Objectives. In the United States, Black persons are disproportionately affected by sexually transmitted infections (STIs), including gonorrhea. Individual behaviors do not fully explain these racial disparities. We explored the association of racial residential segregation with gonorrhea rates among Black persons and hypothesized that specific dimensions of segregation would be associated with gonorrhea rates.Methods. We used 2003 to 2007 national STI surveillance data and 2000 US Census Bureau data to examine associations of 5 dimensions of racial residential segregation and a composite measure of hypersegregation with gonorrhea rates among Black persons in 257 metropolitan statistical areas, overall and by sex and age. We calculated adjusted rate ratios with generalized estimating equations.Results. Isolation and unevenness were significantly associated with gonorrhea rates. Centralization was marginally associated with gonorrhea. Isolation was more strongly associated with gonorrhea among the younger age groups. Concentration, clustering, and hypersegregation were not associated with gonorrhea.Conclusions. Certain dimensions of segregation are important in understanding STI risk among US Black persons. Interventions to reduce sexual risk may need to account for racial residential segregation to maximize effectiveness and reduce existent racial disparities.Sexually transmitted infections (STIs) remain an important public health problem in the United States, with approximately 19 million new infections per year.1 Black persons, especially adolescents, bear a disproportionate burden of most STIs, including gonorrhea.2–6 In 2008, rates of gonorrhea were highest among Black individuals, aged 15 to 19 and 20 to 24 years, compared with any other racial/ethnic and age groups.7,8 Among 15- to 19-year-old adolescents, rates of gonorrhea were nearly 21 times higher for Black (2201.9 per 100 000) than for White adolescents (107.0 per 100 000).7 Untreated gonorrhea can have serious and long-term sequelae, including the facilitation of HIV transmission, infertility, and adverse outcomes for infants born to infected mothers.8Exposure to and infection with STIs are conditioned by many factors, including individual behaviors, relationship patterns, and characteristics of the social environment. Substantial attention has been paid to differences in individual risk behaviors, such as condom use and number of sexual partners, but they do not fully explain racial disparities in STI risk.4 Therefore, focusing solely on these proximate factors to reduce risk and disparities may have only limited effect.4,9 A growing body of research has examined the contribution of contextual factors, such as neighborhood attributes, to sexual risk. Specifically, numerous studies have examined whether living in a neighborhood with lower socioeconomic status is associated with sexual risk behaviors, such as younger age at first sexual intercourse and unprotected sexual intercourse.10–20 The findings have been equivocal, with some showing an association and others not. Therefore, a better understanding of the possible effects of other contextual factors on sexual risk is necessary.Racial residential segregation—the extent to which 2 or more racial groups live separate from one another in a metropolitan area—is a characteristic of the social environment that many Black individuals continue to experience.21 Nearly two thirds of Black persons live in highly segregated areas.9 The available evidence suggests that Black individuals living in more segregated areas, compared with less segregated areas, are at higher risk for certain poor health outcomes, such as low birth weight, mental health conditions, and mortality.9,22–28 No published studies to date have examined the association of racial residential segregation with sexual risk, but recent commentary has identified racial residential segregation as a possible cause of disparities in sexual risk.5,9,22,29–31Racial residential segregation, which describes the racial composition of neighborhoods and the spatial distribution of these neighborhoods in larger metropolitan areas, may be more conceptually relevant to understanding racial disparities than are individual and neighborhood characteristics because it captures the unequal structure for Black and White people across the entire housing market. It has been conceptualized in 5 distinct dimensions—exposure, concentration, centralization, clustering, and unevenness. Metropolitan areas are defined by

1. low exposure (or isolated) if minority members do not often share neighborhoods with other groups,
2. concentrated if minorities occupy relatively little physical space per capita,
3. centralized if minorities are more likely to live in neighborhoods around an urban core relative to other groups,
4. clustered if minorities live in neighborhoods that are crowded together to form a large enclave, and
5. uneven if minorities are overrepresented in some neighborhoods and underrepresented in other neighborhoods.32

Racial residential segregation is hypothesized to lead to differential exposure to STIs through a variety of mechanisms. First, segregation might lead to increased rates of STIs among Black persons by affecting the sexual network (e.g., partner availability and density of individuals).5,31 Second, segregation may create or foster environments (e.g., restricted economic and employment opportunities, disordered neighborhoods) that are conducive to sexual risk behaviors and increased STI risk.9,24,29,31 Each dimension of segregation may have varying degrees of salience in describing distinct mechanisms that affect sexual risk and STI transmission.22,24,31 According to a conceptual model proposed by Acevedo-Garcia,22 exposure, concentration, and, to a lesser extent, centralization are relevant to understanding infectious disease risk because of their effect on transmission patterns and social networks.We used 5 years of national sexually transmitted disease (STD) surveillance data to study the associations of racial residential segregation with gonorrhea rates among Black people in the United States at the metropolitan statistical area (MSA) level. According to Acevedo-Garcia’s model, we hypothesized that certain dimensions of segregation, such as exposure and concentration, would be more positively associated with gonorrhea rates compared with other dimensions of segregation. Additionally, we hypothesized that the associations would be modified by sex and age because of differences across sex and age groups in patterns of social influence.