Future directions in residential segregation and health research: a multilevel approach

Understanding racial-ethnic disparities in health: sociological contributions

This article provides an overview of the contribution of sociologists to the study of racial and ethnic inequalities in health in the United States. It argues that sociologists have made four principal contributions. First, they have challenged and problematized the biological understanding of race. Second, they have emphasized the primacy of social structure and context as determinants of racial differences in disease. Third, they have contributed to our understanding of the multiple ways in which racism affects health. Finally, sociologists have enhanced our understanding of the ways in which migration history and status can affect health. Sociological insights on racial disparities in health have important implications for the development of effective approaches to improve health and reduce health inequities.

Another Mexican birthweight paradox? The role of residential enclaves and neighborhood poverty in the birthweight of Mexican-origin infants

Examining whether contextual factors influence the birth outcomes of Mexican-origin infants in the US may contribute to assessing rival explanations for the so-called Mexican health paradox. We examined whether birthweight among infants born to Mexican-origin women in the US was associated with Mexican residential enclaves and exposure to neighborhood poverty, and whether these associations were modified by nativity (i.e. mother's place of birth). We calculated metropolitan indices of neighborhood exposure to Mexican-origin population and poverty for the Mexican-origin population, and merged with individual-level, year 2000 natality data (n=490,332). We distinguished between neighborhood exposure to US-born Mexican-origin population (i.e. ethnic enclaves) and neighborhood exposure to foreign-born (i.e. Mexico-born) Mexican-origin population (i.e. immigrant enclaves). We used 2-level hierarchical linear regression models adjusting for individual, metropolitan, and regional covariates and stratified by nativity. We found that living in metropolitan areas with high residential segregation of US-born Mexican-origin residents (i.e. high prevalence of ethnic enclaves) was associated with lower birthweight for infants of US-born Mexican-origin mothers before and after covariate adjustment. When simultaneously adjusting for exposure to ethnic and immigrant enclaves, the latter became positively associated with birthweight and the negative effect of the former increased, among US-born mothers. We found no contextual birthweight associations for mothers born in Mexico in adjusted models. Our findings highlight a differential effect of context by nativity, and the potential health effects of ethnic enclaves, which are possibly a marker of downward assimilation, among US-born Mexican-origin women.

Racial discrimination and health among Asian Americans: evidence, assessment, and directions for future research

Research shows that racial discrimination is related to illness among diverse racial and ethnic populations. Studies of racial discrimination and health among Asian Americans, however, remain underdeveloped. In this paper, the authors review evidence on racial discrimination and health among Asian Americans, identify gaps in the literature, and provide suggestions for future research. They identified 62 empirical articles assessing the relation between discrimination and health among Asian Americans. The majority of articles focused on mental health problems, followed by physical and behavioral problems. Most studies find that discrimination was associated with poorer health, although the most consistent findings were for mental health problems. This review suggests that future studies should continue to investigate the following: 1) the measurement of discrimination among Asian Americans, whose experiences may be qualitatively different from those of other racial minority groups; 2) the heterogeneity among Asian Americans, including those factors that are particularly salient in this population, such as ethnic ancestry and immigration history; and 3) the health implications of discrimination at multiple ecologic levels, ranging from the individual level to the structural level.

Neighborhood effects on BMI trends: examining BMI trajectories for Black and White women

Racial disparities in obesity among women in the United States are substantial but the causes of these disparities are poorly understood. We examined changes in body mass index (BMI) trajectories for Black and White women as a function of neighborhood disadvantage and racial composition of the neighborhoods within which respondents are clustered. Using four waves of the Americans' Changing Lives (ACL) survey, we estimated multilevel models predicting BMI trajectories over a 16-year period. Even after controlling for individual-level socio-demographics, risk and protective factors, and baseline neighborhood disadvantage and racial composition, substantial racial disparities in BMI persisted at each time point, and widened over time (p < 0.05). Baseline neighborhood disadvantage is associated with BMI and marginally reduces racial disparities in BMI, but it does not predict BMI changes over time. However, without neighborhood-level variables, the BMI trajectory model is misspecified, highlighting the importance of including community factors in future research.

Quantifying Separate and Unequal: Racial-Ethnic Distributions of Neighborhood Poverty in Metropolitan America

Researchers measuring racial inequality of neighborhood environment across metropolitan areas (MAs) have traditionally employed segregation measures, yet such measures are limited for incorporating a third axis of information, including neighborhood opportunity. Using Census 2000 tract-level data for the largest U.S. MAs, we introduce the interquartile-range overlap statistic to summarize the substantial separation of entire distributions of neighborhood environments between racial groups. We find neighborhood poverty distributions for minorities overlap only 27% with those for whites. Further, the separation of racial groups into neighborhoods of differing poverty rates is strongly correlated with racial residential segregation. The overlap statistic provides a straightforward, policy-relevant metric for monitoring progress towards achieving more equal environments of neighborhood opportunity space.

A Model of Racial Residential History and Its Association with Self-Rated Health and Mortality Among Black and White Adults in the United States

We construct a dynamic racial residential history typology and examine its association with self-rated health and mortality among black and white adults. Data are from a national survey of U.S. adults, combined with census tract data from 1970-1990. Results show that racial disparities in health and mortality are explained by both neighborhood contextual and individual socioeconomic factors. Results suggest that living in an established black neighborhood or in an established interracial neighborhood may actually be protective of health, once neighborhood poverty is controlled. Examining the dynamic nature of neighborhoods contributes to an understanding of health disparities.

Racialized identity and health in Canada: results from a nationally representative survey

This article uses survey data to investigate health effects of racialization in Canada. The operative sample was comprised of 91,123 Canadians aged 25 and older who completed the 2003 Canadian Community Health Survey. A "racial and cultural background" survey question contributed a variable that differentiated respondents who identified with Aboriginal, Black, Chinese, Filipino, Latin American, South Asian, White, or jointly Aboriginal and White racial/cultural backgrounds. Indicators of diabetes, hypertension and self-rated health were used to assess health. The healthy immigrant effect suppressed some disparity in risk for diabetes by racial/cultural identification. In logistic regression models also containing gender, age, and immigrant status, no racial/cultural identifications corresponded with significantly better health outcomes than those reported by survey respondents identifying as White. Subsequent models indicated that residential locale did little to explain the associations between racial/cultural background and health and that socioeconomic status was only implicated in relatively poor health outcomes for respondents identifying as Aboriginal or Aboriginal/White. Sizable and statistically significant relative risks for poor health for respondents identifying as Aboriginal, Aboriginal/White, Black, Chinese, or South Asian remained unexplained by the models, suggesting that other explanations for health disparities by racialized identity in Canada - perhaps pertaining to experiences with institutional racism and/or the wear and tear of experiences of racism and discrimination in everyday life - also deserve empirical investigation in this context.

Health and healthcare perspectives of African American residents of an unincorporated community: a qualitative assessment

Residential perspectives about health in unincorporated communities are virtually unexplored. In this study, we conducted focus groups to assess individual and community health status, environmental health mediators, and systematic barriers to healthcare among African American residents of the unincorporated town, Fresno, Texas. Residents described their individual health status as excellent, but depicted the community's health status as fair. Unaffordable healthcare, limited access to healthcare, and environmental mediators were perceived to impact the Fresno community's health status. Our findings suggest a need to begin to examine health outcomes for minority residents in other unincorporated communities.

Is segregation bad for your health?

For decades, racial residential segregation has been observed to vary with health outcomes for African Americans, although only recently has interest increased in the public health literature. Utilizing a systematic review of the health and social science literature, the authors consider the segregation-health association through the lens of 4 questions of interest to epidemiologists: How is segregation best measured? Is the segregation-health association socially or biologically plausible? What evidence is there of segregation-health associations? Is segregation a modifiable risk factor? Thirty-nine identified studies test an association between segregation and health outcomes. The health effects of segregation are relatively consistent, but complex. Isolation segregation is associated with poor pregnancy outcomes and increased mortality for blacks, but several studies report health-protective effects of living in clustered black neighborhoods net of social and economic isolation. The majority of reviewed studies are cross-sectional and use coarse measures of segregation. Future work should extend recent developments in measuring and conceptualizing segregation in a multilevel framework, build upon the findings and challenges in the neighborhood-effects literature, and utilize longitudinal data sources to illuminate opportunities for public health action to reduce racial disparities in disease.

Segregation and disparities in health services use

We compared race disparities in health services use in a national sample of adults from the 2002 Medical Expenditure Panel Survey and data from the Exploring Health Disparities in Integrated Communities Project, a 2003 survey of adult residents from a low-income integrated urban community in Maryland. In the Medical Expenditure Panel Survey data, African Americans were less likely to have a health care visit compared with Whites. However, in the Exploring Health Disparities in Integrated Communities Project, the integrated community, African Americans were more likely to have a health care visit than Whites. The race disparities in the incidence rate of health care use among persons who had at least one visit were similar in both samples. Our findings suggest that disparities in health care utilization may differ across communities and that residential segregation may be a confounding factor.

Are immigrant enclaves healthy places to live? The Multi-ethnic Study of Atherosclerosis

The growing size and changing composition of the foreign-born population in the USA highlights the importance of examining the health consequences of living in neighborhoods with higher proportions of immigrants. Using data from the Multi-ethnic Study of Atherosclerosis in four US cities, we examined whether neighborhood immigrant composition was associated with health behaviors (diet, physical activity) among Hispanic and Chinese Americans (n=1902). Secondarily we tested whether neighborhoods with high proportions of immigrants exhibited better or worse neighborhood quality, and whether these dimensions of neighborhood quality were associated with healthy behaviors. Neighborhood immigrant composition was defined based on the Census 2000 tract percent of foreign-born from Latin-America, and separately, percent foreign-born from China. After adjustment for age, gender, income, education, neighborhood poverty, and acculturation, living in a tract with a higher proportion of immigrants was associated with lower consumption of high-fat foods among Hispanics and Chinese, but with being less physically active among Hispanics. Residents in neighborhoods with higher proportions of immigrants reported better healthy food availability, but also worse walkability, fewer recreational exercise resources, worse safety, lower social cohesion, and lower neighborhood-based civic engagement. Associations of neighborhood immigrant composition with diet persisted after adjustment for reported neighborhood characteristics, and associations with physical activity were attenuated. Respondent-reported neighborhood healthy food availability, walkability, availability of exercise facilities and civic participation remained associated with behaviors after adjusting for immigrant composition and other covariates. Results show that living in an immigrant enclave is not monolithically beneficial and may have different associations with different health behaviors.

Neighborhood residential segregation and mental health: a multilevel analysis on Hispanic Americans in Chicago

Compared with the relationship between neighborhood-level residential segregation and physical health of Hispanic Americans, less is known about how neighborhood residential segregation affects mental health. This study examines if, and how, neighborhood residential segregation is associated with the mental health of Puerto Rican and Mexican Americans in Chicago. Multilevel analyses reveal that neighborhood residential segregation is positively associated with depressive symptoms and anxiety in both groups. Neighborhood segregation, however, has more salient effects on the mental health of Mexican Americans. For Puerto Rican Americans, the effects of neighborhood segregation on mental health become nonsignificant after controlling for neighborhood-level income and individual-level covariates, whereas neighborhood segregation is strongly associated with the mental health of Mexican Americans even after controlling for other covariates. These findings show that living in a Mexican American-dominated community is not beneficial to mental health, in contrast to findings for physical health shown in previous studies.

Small-area racial disparity in stroke mortality: an application of bayesian spatial hierarchical modeling

BACKGROUND

In the United States, excess burden of stroke mortality has persisted among African Americans compared with whites despite declines in stroke mortality for both groups. New insights may be gleaned by examining local, small-area patterns in racial disparities in stroke.

METHODS

The study population includes all non-Hispanic African Americans and non-Hispanic whites aged 35 to 64 in the southeastern United States during 1999 to 2002. We assessed county-level numbers of stroke deaths and population estimates in a Bayesian spatial hierarchical modeling framework allowing for inclusion of potential covariates (poverty and rurality), and generating county-specific model-based estimates of both absolute and relative racial disparity. The resulting estimates of race-specific stroke death rates, relative racial disparity, and absolute racial disparity were expressed in maps.

RESULTS

After adjustment for age, poverty, and rurality, county-level estimates of relative racial disparity ranged from 2.3 to 3.3 and estimates of absolute racial disparity ranged from 19 to 45 excess deaths per 100,000. For both racial groups, stroke death rates were higher in rural areas and with increasing poverty. High relative racial disparity was concentrated primarily in the eastern portion of the region and large absolute racial disparity was concentrated primarily in the western portion.

CONCLUSIONS

The results highlight the pervasiveness and magnitude of substantial local racial disparities in stroke mortality in the southeast.

Racial disparities in the development of breast cancer metastases among older women: a multilevel study

BACKGROUND

Distant metastases are the most common and lethal type of breast cancer relapse. The authors examined whether older African American breast cancer survivors were more likely to develop metastases compared with older white women. They also examined the extent to which 6 pathways explained racial disparities in the development of metastases.

METHODS

The authors used 1992-1999 Surveillance, Epidemiology, and End Results (SEER) data with 1991-1999 Medicare data. They used Medicare's International Classification of Diseases, Ninth Revision, Clinical Modification codes to identify metastases of respiratory and digestive systems, brain, bone, or other unspecified sites. The 6 pathways consisted of patient characteristics, tumor characteristics, type of treatment received, access to medical care, surveillance mammography use, and area-level characteristics (poverty rate and percentage African American) and were obtained from the SEER or Medicare data.

RESULTS

Of the 35,937 women, 10.5% developed metastases. In univariate analysis, African American women were 1.61 times (95% confidence interval [CI], 1.54-1.83) more likely to develop metastasis than white women. In multivariate analysis, tumor grade, stage at diagnosis, and census-tract percentage African American explained why African American women were more likely to develop metastases than white women (hazard ratio, 0.84; 95% CI, 0.68-1.03).

CONCLUSIONS

Interventions to reduce late-stage breast cancer among African Americans also may reduce racial disparities in subsequent increased risk of developing metastasis. African Americans diagnosed with high-grade breast cancer could be targeted to reduce their risk of metastasis. Future studies should identify specific reasons why the racial distribution in census tracts was associated with racial disparities in the risk of breast cancer metastases.

Perceived everyday racism, residential segregation, and HIV testing among patients at a sexually transmitted disease clinic

OBJECTIVES

More than one quarter of HIV-infected people are undiagnosed and therefore unaware of their HIV-positive status. Blacks are disproportionately infected. Although perceived racism influences their attitudes toward HIV prevention, how racism influences their behaviors is unknown. We sought to determine whether perceiving everyday racism and racial segregation influence Black HIV testing behavior.

METHODS

This was a clinic-based, multilevel study in a North Carolina city. Eligibility was limited to Blacks (N = 373) seeking sexually transmitted disease diagnosis or screening. We collected survey data, block group characteristics, and lab-confirmed HIV testing behavior. We estimated associations using logistic regression with generalized estimating equations.

RESULTS

More than 90% of the sample perceived racism, which was associated with higher odds of HIV testing (odds ratio = 1.64; 95% confidence interval = 1.07, 2.52), after control for residential segregation, and other covariates. Neither patient satisfaction nor mechanisms for coping with stress explained the association.

CONCLUSIONS

Perceiving everyday racism is not inherently detrimental. Perceived racism may improve odds of early detection of HIV infection in this high-risk population. How segregation influences HIV testing behavior warrants further research.

Discrimination and racial disparities in health: evidence and needed research

This paper provides a review and critique of empirical research on perceived discrimination and health. The patterns of racial disparities in health suggest that there are multiple ways by which racism can affect health. Perceived discrimination is one such pathway and the paper reviews the published research on discrimination and health that appeared in PubMed between 2005 and 2007. This recent research continues to document an inverse association between discrimination and health. This pattern is now evident in a wider range of contexts and for a broader array of outcomes. Advancing our understanding of the relationship between perceived discrimination and health will require more attention to situating discrimination within the context of other health-relevant aspects of racism, measuring it comprehensively and accurately, assessing its stressful dimensions, and identifying the mechanisms that link discrimination to health.

Discrimination and racial disparities in health: evidence and needed research

This paper provides a review and critique of empirical research on perceived discrimination and health. The patterns of racial disparities in health suggest that there are multiple ways by which racism can affect health. Perceived discrimination is one such pathway and the paper reviews the published research on discrimination and health that appeared in PubMed between 2005 and 2007. This recent research continues to document an inverse association between discrimination and health. This pattern is now evident in a wider range of contexts and for a broader array of outcomes. Advancing our understanding of the relationship between perceived discrimination and health will require more attention to situating discrimination within the context of other health-relevant aspects of racism, measuring it comprehensively and accurately, assessing its stressful dimensions, and identifying the mechanisms that link discrimination to health.

The effect of racial residential segregation on black infant mortality

Economic differences and proximal risk factors do not fully explain the persistent high infant mortality rates of African Americans (blacks). The authors hypothesized that racial residential segregation plays an independent role in high black infant mortality rates. Segregation restricts social and economic advantage and imposes negative environmental exposures that black women and infants experience. The study sample was obtained from the 2000-2002 US Linked Birth/Infant Death records and included 677,777 black infants residing in 64 cities with 250,000 or more residents. Outcomes were rates of all-cause infant mortality, postneonatal mortality, and external causes of death. Segregation was measured by using the isolation index (dichotomized at 0.60) from the 2000 US Census Housing Patterns. Propensity score matching methods were used. After matching on propensity scores, no independent effect of segregation on black infant mortality rates was found. Results show little statistical evidence that segregation plays an independent role in black infant mortality. However, a key finding is that it is difficult to disentangle contextual effects from the characteristics of individuals.

Invited commentary: residential segregation and health--the complexity of modeling separate social contexts

When researching racial disparities in health, residential segregation cannot be ignored. Because of segregation, contextual differences by race are so pronounced that ignoring them may lead to mis-estimating the effect of individual-level factors. However, given the stark racial separation of social contexts, researching how residential segregation and neighborhood inequality contribute to racial health disparities remains methodologically challenging. Estimating the contribution of neighborhood effects to health disparities would require overlap in the racial distributions of neighborhood environment, for example, in the distributions of neighborhood poverty. Because of segregation, though, the extent of such overlap is extremely restricted. Previous analyses of the 2000 US Census found, on average, only a 24% overlap between the distribution of neighborhood poverty for black children and that for white children in metropolitan areas. Propensity score methods may be 1 useful tool for addressing limited overlap or exchangeability. However, as shown by their application to the segregation and health relation, their use should be informed by a sound conceptualization of the scale of the social exposure of interest, the hypothesized pathways between the exposure and the health outcome, and possible unmeasured confounders.

Discrimination and racial disparities in health: evidence and needed research

This paper provides a review and critique of empirical research on perceived discrimination and health. The patterns of racial disparities in health suggest that there are multiple ways by which racism can affect health. Perceived discrimination is one such pathway and the paper reviews the published research on discrimination and health that appeared in PubMed between 2005 and 2007. This recent research continues to document an inverse association between discrimination and health. This pattern is now evident in a wider range of contexts and for a broader array of outcomes. Advancing our understanding of the relationship between perceived discrimination and health will require more attention to situating discrimination within the context of other health-relevant aspects of racism, measuring it comprehensively and accurately, assessing its stressful dimensions, and identifying the mechanisms that link discrimination to health.

Beyond the Census Tract: Patterns and Determinants of Racial Segregation at Multiple Geographic Scales

The census tract-based residential segregation literature rests on problematic assumptions about geographic scale and proximity. We pursue a new tract-free approach that combines explicitly spatial concepts and methods to examine racial segregation across egocentric local environments of varying size. Using 2000 census data for the 100 largest U.S. metropolitan areas, we compute a spatially modified version of the information theory index H to describe patterns of black-white, Hispanic-white, Asian-white, and multi-group segregation at different scales. The metropolitan structural characteristics that best distinguish micro-segregation from macro-segregation for each group combination are identified, and their effects are decomposed into portions due to racial variation occurring over short and long distances. A comparison of our results to those from tract-based analyses confirms the value of the new approach.

Place matters: variation in the black/white very preterm birth rate across U.S. metropolitan areas, 2002-2004

OBJECTIVE

We reported on the distribution of very preterm (VPT) birth rates by race across metropolitan statistical areas (MSAs).

METHODS

Rates of singleton VPT birth for non-Hispanic white, non-Hispanic black, and Hispanic women were calculated with National Center for Health Statistics 2002-2004 natality files for infants in 168 MSAs. Subanalysis included stratification by parity, age, smoking, maternal education, metropolitan size, region, proportion of MSA that was black, proportion of black population living below the poverty line, and indices of residential segregation.

RESULTS

The mean metropolitan-level VPT birth rate was 12.3, 34.8, and 15.7 per 1,000 live births for white, black, and Hispanic women, respectively. There was virtually no overlap in the white and black distributions. The variation in mean risk across cities was three times greater for black women compared with white women. The threefold disparity in mean rate, and two- to threefold increased variation as indicated by standard deviation, was maintained in all subanalyses.

CONCLUSION

Compared with white women, black women have three times the mean VPT birth risk, as well as three times the variance in city-level rates. The racial disparity in VPT birth rates was composed of characteristics that were constant across MSAs, as well as factors that varied by MSA. The increased sensitivity to place for black women was unexplained by measured maternal and metropolitan factors. Understanding determinants of differences in both the mean risk and the variation of risk among black and white women may contribute to reducing the disparity in risk between races.

Challenges for multilevel health disparities research in a transdisciplinary environment

Numerous factors play a part in health disparities. Although health disparities are manifested at the level of the individual, other contexts should be considered when investigating the associations of disparities with clinical outcomes. These contexts include families, neighborhoods, social organizations, and healthcare facilities. This paper reports on health disparities research as a multilevel research domain from the perspective of a large national initiative. The Centers for Population Health and Health Disparities (CPHHD) program was established by the NIH to examine the highly dimensional, complex nature of disparities and their effects on health. Because of its inherently transdisciplinary nature, the CPHHD program provides a unique environment in which to perform multilevel health disparities research. During the course of the program, the CPHHD centers have experienced challenges specific to this type of research. The challenges were categorized along three axes: sources of subjects and data, data characteristics, and multilevel analysis and interpretation. The CPHHDs collectively offer a unique example of how these challenges are met; just as importantly, they reveal a broad range of issues that health disparities researchers should consider as they pursue transdisciplinary investigations in this domain, particularly in the context of a large team science initiative.

Occupational segregation as a determinant of US worker health

BACKGROUND

Racial segregation provides a potential mechanism to link occupations with adverse health outcomes.

METHODS

An African-American segregation index (I(AA)) was calculated for US worker groups from the nationally representative pooled 1986-1994 National Health Interview Survey (n = 451,897). Ranking and logistic regression analyses were utilized to document associations between I(AA) and poor worker health.

RESULTS

There were consistent positive associations between employment in segregated occupations and poor worker health, regardless of covariate adjustment or stratification (e.g., age, gender, income, education, or geographic region). This association between segregation and poor health was stronger for White as compared to African-American workers.

CONCLUSIONS

Occupational segregation negatively affects all workers. Potential mechanisms need to be identified through which occupational segregation may adversely impact worker health.

Race, racism, and racial disparities in adverse birth outcomes

While the biologic authenticity of race remains a contentious issue, the social significance of race is indisputable. The chronic stress of racism and the social inequality it engenders may be underlying social determinants of persistent racial disparities in health, including infant mortality, preterm delivery, and low birth weight. This article describes the problem of racial disparities in adverse birth outcomes; outlines the multidimensional nature of racism and the pathways by which it may adversely affect health; and discusses the implications for clinical practice.

Do bonding, bridging, and linking social capital affect preventable hospitalizations?

OBJECTIVE

To examine the relationship between social capital and preventable hospitalizations (PHs).

DATA SOURCES

Administrative and secondary data for Florida (hospital discharge, U.S. Census, voting, nonprofits, faith-based congregations, uninsured, safety net and primary care providers, and hospital beds).

STUDY DESIGN

Cross-sectional, zip code-level multivariate analyses to examine the associations among social capital, primary care resources, and adult PHs and pediatric asthma hospitalizations.

DATA EXTRACTION

Data were merged at the zip code-level (n=837).

PRINCIPAL FINDINGS

Few of the social capital measures were independently associated with PHs: longer mean commute times (reduced bonding social capital) were related to higher adult rates; more racial and ethnic diversity (increased bridging social capital) was related to lower nonelderly adult rates but higher pediatric rates; more faith-based organizations (linking social capital) were associated with higher nonelderly adult rates. Having a safety net clinic within 20 miles was associated with lower adult rates, while general internists were associated with higher rates. More pediatricians per capita were related to higher pediatric rates.

CONCLUSIONS

The importance of social capital for health care access is unclear. Some bonding and bridging ties were related to PHs, but differentially across age groups; more work is needed to operationalize linking ties.

Racial segregation and disparities in cancer stage for seniors

BACKGROUND

Disparities in cancer survival may be related to differences in stage. Segregation may be associated with disparities in stage, particularly for cancers for which screening promotes survival.

OBJECTIVES

The objective of the study was to examine whether segregation modifies racial/ethnic disparities in stage.

DESIGN

The design of the study was analysis of Surveillance, Epidemiology, and End Results Medicare data for seniors with breast, colorectal, lung, and prostate cancer (n = 410,870).

MEASUREMENTS AND MAIN RESULTS

The outcome was early- versus late-stage diagnosis. Area of residence was categorized into 4 groups: low segregation/high income (potentially the most advantaged), high segregation/high income, low segregation/low income, and high segregation/low income (possibly the most disadvantaged). Blacks were less likely than whites to be diagnosed with early-stage breast, colorectal, or prostate cancer, regardless of area. For colorectal cancer, the black/white disparity was largest in low-segregation/low-income areas (black/white odds ratio [OR] of early stage 0.51) and smallest in the most segregated areas (ORs 0.71 and 0.74, P < .005). Differences in disparities in stage by area category were not apparent for breast, prostate, or lung cancer. Whereas there were few Hispanic-white differences in early-stage diagnosis, the Hispanic/white disparity in early-stage diagnosis of breast cancer was largest in low-segregation/low-income areas (Hispanic/white OR of early stage 0.54) and smallest in high-segregation/low-income areas (OR 0.96, P < .05 compared to low-segregation/low-income areas).

CONCLUSIONS

Disparities in stages for cancers with an established screening test were smaller in more segregated areas.

Association of regional racial/cultural context and socioeconomic status with arthritis in the population: a multilevel analysis

OBJECTIVE

To examine the extent to which differences in individual- and regional-level socioeconomic status and racial/cultural origin account for geographic variations in the prevalence of self-reported arthritis, and to determine whether regional characteristics modify the effect of individual characteristics associated with reporting arthritis.

METHODS

Analyses were based on the 2000-2001 Canadian Community Health Survey (>15 years, n = 127,513). Arthritis was self-reported as a long-term condition diagnosed by a health professional. A 2-level logistic regression model was used to identify predictors of reporting arthritis. Individual-level variables included age, sex, income, education, immigration status, racial/cultural origin, smoking, physical activity, and body mass index. Regional-level variables included the proportion of low-income families, low education, unemployment, recent immigrants, Aboriginals, and Asians.

RESULTS

At the individual level, age, sex, low income, low education, Aboriginal origin, current smoking, and overweight/obesity were positively associated with reporting arthritis; recent immigration and Asian origin were negatively associated with reporting arthritis. At the regional level, percentages of low-income families and the Aboriginal population were independently associated with reporting arthritis. Regional income and racial/cultural origin moderated the effects of individual income and racial/cultural origin; low-income individuals residing in regions with a higher proportion of low-income families reported arthritis more than low-income individuals living in better-income regions.

CONCLUSION

Both individual and regional factors were found to contribute to variations in the prevalence of arthritis, although significant unexplained variation remained. Further research is required to better understand the mechanisms that underlie these regional effects and to identify other contributing factors to the remaining variation.

Implementing safe routes to school: application for the socioecological model and issues to consider

The newly established national Safe Routes to School (SRTS) program has the potential to positively influence individuals, communities, and the environment regardless of race, ethnicity, or socioeconomic status. Many communities are applying their interest in physical activity promotion toward creating policies and programs to encourage active travel, though many barriers exist. SRTS legislation provides funds to address some of the barriers and improve the ability of students to safely walk and bicycle to school. SRTS requires that 70% to 90% of the funds be used for infrastructure projects (i.e., engineering treatments, such as sidewalk construction), and 10% to 30% for noninfrastructure activities, such as education, encouragement, and enforcement. The socioecological model (SEM) is widely used in public health and includes five levels of influence on behavior, from individual to public policy. Application of the SEM to SRTS provides a framework for a comprehensive approach to improve active travel to school.

A participatory action research pilot study of urban health disparities using rapid assessment response and evaluation

Healthy People 2010 made it a priority to eliminate health disparities. We used a rapid assessment response and evaluation (RARE) to launch a program of participatory action research focused on health disparities in an urban, disadvantaged Black community serviced by a major south Florida health center. We formed partnerships with community members, identified local health disparities, and guided interventions targeting health disparities. We describe the RARE structure used to triangulate data sources and guide intervention plans as well as findings and conclusions drawn from scientific literature and epidemiological, historic, planning, clinical, and ethnographic data. Disenfranchisement and socioeconomic deprivation emerged as the principal determinants of local health disparities and the most appropriate targets for intervention.

Neighborhood economic disadvantage, violent crime, group density, and pregnancy outcomes in a diverse, urban population

Prior research has established associations between pregnancy outcomes and specific neighborhood characteristics, including economic disadvantage, violent crime, and racial/ethnic segregation. Recently, associations have also been found between various health outcomes and group density, the degree to which an individual is a racial or ethnic majority in his or her local community. The objective of this study was to determine the extent to which census tract economic disadvantage, violent crime rate, and group density are associated with pregnancy outcomes among White, Black, and Hispanic infants in a large metropolitan setting. This cross-sectional study utilized 1990 census data, 1991 crime data, and 1991 birth certificate information for singleton live births in Chicago, Illinois. Results show substantial racial segregation in Chicago, with 35% of census tracts having more than 90% Black residents and 45% of census tracts having fewer than 10% Black residents. After stratifying by maternal race/ethnicity, we used multilevel analyses to model pregnancy outcomes as a function of individual and census tract characteristics. Among all racial/ethnic groups, violent crime rate accounted for most of the negative association between tract economic disadvantage and birth weight. Group density was also associated with birth weight but this association was stronger among Whites and Hispanics than among Blacks. Further analysis revealed that group density was more strongly associated with preterm birth while violent crime rate was more strongly associated with small for gestational age. These results suggest that group density and violent crime may impact birth weight via different mechanisms.

Early-life conditions and mechanisms of population health vulnerabilities

The social status of groups is key to determining health vulnerability at the population level. The impact of material and psychological stresses imposed by social inequities and marginalization is felt most intensely during perinatal/early childhood and puberty/adolescent periods, when developmental genes are expressed and interact with social-physical environments. The influence of chronic psychosocial stresses on gene expression via neuroendocrine regulatory dysfunction is crucial to understanding the biological bases of adult health vulnerability. Studying childhood biology vulnerabilities to neighborhood environments will aid the crafting of multifaceted, multilevel public policy interventions providing immediate benefits and compounded long-term population health yields.

Overcoming confounding of race with socio-economic status and segregation to explore race disparities in smoking

AIMS

We examined the nature of racial disparities in smoking status within a sample that accounts for two major confounding factors in health disparities research--racial segregation and socio-economic status. Also, we sought to determine the generalizability of our sample.

DESIGN AND SETTING

Cross-sectional study based on data from the Exploring Health Disparities in Integrated Communities Study in south-west Baltimore, MD (EHDIC-SWB) and a subsample of respondents in the 2002 National Health Interview Survey (NHIS) that was matched to EHIDC-SWB. The final matched data set sample size was 2948 adults (1474 EHDIC-SWB; 1474 matched NHIS).

MEASUREMENTS

Our outcome variables were life-time and current smoking status and number of cigarettes smoked daily. Independent variables include race, age gender, educational attainment and income.

FINDINGS

In the adjusted models, whites had greater odds than blacks of current smoking and reported smoking more cigarettes in the EHDIC-SWB sample, but there were no race differences in current smoking status or in the number of cigarettes smoked per day in the NHIS. The prevalence rates for both life-time and current smoking were substantially greater in the EHDIC-SWB sample, but in comparisons of blacks and whites across samples we found that the magnitude of the difference between the samples was greatest for whites.

CONCLUSIONS

Unadjusted national estimates of race disparities as reported in national reports may be biased because of differential risk exposure among people of different race groups. Race differences in social and environmental contexts account partially for racial differences in smoking patterns.

Associations between residential segregation and smoking during pregnancy among urban African-American women

Approximately 10% of African-American women smoke during pregnancy compared to 16% of White women. While relatively low, the prevalence of smoking during pregnancy among African-American women exceeds the Healthy People 2010 goal of 1%. In the current study, we address gaps in extant research by focusing on associations between racial/ethnic residential segregation and smoking during pregnancy among urban African-American women. We linked measures of segregation to birth certificates and data from the 2000 census in a sample of US-born African-American women (n = 403,842) living in 216 large US Metropolitan Statistical Areas (MSAs). Logistic regression models with standard errors adjusted for multiple individual observations within MSAs were used to examine associations between segregation and smoking during pregnancy and to control for important socio-demographic confounders. In all models, a u-shaped relationship was observed. Both low segregation and high segregation were associated with higher odds of smoking during pregnancy when compared to moderate segregation. We speculate that low segregation reflects a contagion process, whereby salutary minority group norms are weakened by exposure to the more harmful behavioral norms of the majority population. High segregation may reflect structural attributes associated with smoking such as less stringent tobacco control policies, exposure to urban stressors, targeted marketing of tobacco products, or limited access to treatment for tobacco dependence. A better understanding of both deleterious and protective contextual influences on smoking during pregnancy could help to inform interventions designed to meet Healthy People 2010 target goals.

Exceptions to the rule: Healthy deprived areas and unhealthy wealthy areas

In general, inhabitants of low socio-economic areas are unhealthier than inhabitants of high socio-economic areas, but some areas are an exception to this rule. These exceptions imply that other factors besides the socio-economic level of an area contribute to the health of the inhabitants of an area, e.g. environmental factors. In our study we concentrate on areas within the Netherlands that are healthier or unhealthier than could be expected based on their socio-economic level. This study first identifies these areas and secondly determines which area characteristics distinguish these areas from those areas where the level of health is in agreement with their socio-economic level. We used nation-wide data on neighbourhood differences in population composition (gender, age, marital status and ethnicity), urbanisation and two health indicators: mortality and hospitalisation rates. In the Netherlands, many areas are healthier or unhealthier than could be expected based on their income level alone. Areas with higher mortality rates than expected are mainly urban areas with high percentages of elderly people and persons living alone. Similar but opposite associations are observed for areas with lower mortality rates than expected, which are further characterised by a low percentage of non-western immigrants. Areas with lower hospitalisation rates than expected are mainly rural areas with few non-western immigrants. From these results, we conclude that urbanisation and residential segregation based on age, ethnicity and marital status might be important contributors to geographical health inequalities.

Advancing the science of health disparities research

Research to eliminate health disparities in the United States is best approached from the perspective of population health. The objectives of this paper are to: (a) describe how ongoing research at the eight national Centers for Population Health and Health Disparities (CPHHD) is using a population health perspective and a community-based approach to advance the field of health disparities research; and (b) to discuss potential implications of such research for health policies that target some of the determinants of population health.

Ghettoizing outdoor advertising: disadvantage and ad panel density in black neighborhoods

This study investigated correlates of outdoor advertising panel density in predominantly African American neighborhoods in New York City. Research shows that black neighborhoods have more outdoor advertising space than white neighborhoods, and these spaces disproportionately market alcohol and tobacco advertisements. Thus, understanding the factors associated with outdoor advertising panel density has important implications for public health. We linked 2000 census data with property data at the census block group level to investigate two neighborhood-level determinants of ad density: income level and physical decay. Results showed that block groups were exposed to an average of four ad spaces per 1,000 residents and that vacant lot square footage was a significant positive predictor of ad density. An inverse relationship between median household income and ad density did not reach significance, suggesting that relative affluence did not protect black neighborhoods from being targeted for outdoor advertisements.

Race, race-based discrimination, and health outcomes among African Americans

Persistent and vexing health disadvantages accrue to African Americans despite decades of work to erase the effects of race discrimination in this country. Participating in these efforts, psychologists and other social scientists have hypothesized that African Americans' continuing experiences with racism and discrimination may lie at the root of the many well-documented race-based physical health disparities that affect this population. With newly emerging methodologies in both measurement of contextual factors and functional neuroscience, an opportunity now exists to cleave together a comprehensive understanding of the ways in which discrimination has harmful effects on health. In this article, we review emerging work that locates the cause of race-based health disparities in the external effects of the contextual social space on the internal world of brain functioning and physiologic response. These approaches reflect the growing interdisciplinary nature of psychology in general, and the field of race relations in particular.

The significance of neighbourhood context to child and adolescent health and well-being: a systematic review of multilevel studies

Growing up in a poor neighbourhood has negative effects on children and adolescents. In the literature it has been concluded that the risk of low birth weight, childhood injury and abuse, and teenage pregnancy or criminality double in poor areas. However, the validity of such studies has been questioned, as they have been associated with ecological or individualistic fallacies. Studies using multilevel technique might thus contribute important knowledge in this field. The present review clarifies the importance of neighbourhood contextual factors in child and adolescent health outcomes, through considering only studies using multilevel technique. Keyword searching of the Medline, ERIC, PsycInfo, Sociological Abstracts, and Social Citation Index databases was performed. Original studies using multilevel technique to examine the effect of neighbourhood characteristics on child and adolescent health outcomes, and focusing on populations in high-income countries were included. Neighbourhood socioeconomic status and social climate were shown to have small to moderate effects on child health outcomes, i.e. birth weight, injuries, behavioural problems, and child maltreatment. On average, 10% of variation in health outcomes was explained by neighbourhood determinants, after controlling for important individual and family variables. This review demonstrates that interventions in underprivileged neighbourhoods can reduce health risks to children, especially in families that lack resources. An analysis of methodological fallacies indicates that observed effects and effect sizes can be underestimated, and that interventions may well have greater impact than this review was able to establish.

When home is where the stress is: expanding the dimensions of housing that influence asthma morbidity

The influence of physical housing quality on childhood asthma expression, especially the effect of exposure to moulds, allergens, and pollutants, is well documented. However, attempts to explain increasing rates and severity of childhood asthma solely through physical environmental factors have been unsuccessful, and additional exposures may be involved. Increasing evidence has linked psychological stress and negative affective states to asthma expression. At the same time, recent scholarship in the social sciences has focused on understanding how social environments, such as housing, "get under the skin" to influence health, and suggests that psychological factors play a key role. While there is relevant overlapping research in social science, psychology, economics, and health policy in this area, findings from these disciplines have not yet been conceptually integrated into ongoing asthma research. We propose to expand the dimensions of housing considered in future asthma research to include both physical and psychological aspects which may directly and indirectly influence onset and severity of disease expression. This synthesis of overlapping research from a number of disciplines argues for the systematic measure of psychological dimensions of housing and consideration of the interplay between housing stress and physical housing characteristics in relation to childhood asthma.

Residential segregation and injection drug use prevalence among Black adults in US metropolitan areas

OBJECTIVES

We analyzed the relations of two 1990 dimensions of racial residential segregation (isolation and concentration) with 1998 injection drug use prevalence among Black adult residents of 93 large US metropolitan statistical areas (MSAs).

METHODS

We estimated injection drug use prevalence among Black adults in each MSA by analyzing 3 databases documenting injection drug users' encounters with the health care system. Multiple linear regression methods were used to investigate the relationship of isolation and concentration to the natural logarithm of Black adult injection drug use prevalence, controlling for possible confounders.

RESULTS

The median injection drug use prevalence was 1983 per 100000 Black adults (interquartile range: 1422 to 2759 per 100000). The median isolation index was 0.48 (range: 0.05 to 0.84): in half the MSAs studied, the average Black resident inhabited a census tract where 48% or more of the residents were Black. The multiple regression model indicates that an increase of 0.50 in the isolation index was associated with a 23% increase in injection drug use prevalence among Black adults. Concentration was unrelated to the outcome.

CONCLUSIONS

Residential isolation is positively related to Black injection drug use prevalence in MSAs. Research into the pathways linking isolation to injection drug use is needed.

The riskscape and the color line: examining the role of segregation in environmental health disparities

Environmental health researchers, sociologists, policy-makers, and activists concerned about environmental justice argue that communities of color who are segregated in neighborhoods with high levels of poverty and material deprivation are also disproportionately exposed to physical environments that adversely affect their health and well-being. Examining these issues through the lens of racial residential segregation can offer new insights into the junctures of the political economy of social inequality with discrimination, environmental degradation, and health. More importantly, this line of inquiry may highlight whether observed pollution--health outcome relationships are modified by segregation and whether segregation patterns impact diverse communities differently. This paper examines theoretical and methodological questions related to racial residential segregation and environmental health disparities. We begin with an overview of race-based segregation in the United States and propose a framework for understanding its implications for environmental health disparities. We then discuss applications of segregation measures for assessing disparities in ambient air pollution burdens across racial groups and go on to discuss the applicability of these methods for other environmental exposures and health outcomes. We conclude with a discussion of the research and policy implications of understanding how racial residential segregation impacts environmental health disparities.

Facility and county effects on racial differences in nursing home quality indicators

This study's goal was to examine the effects of nursing home (NH) and county racial mix on quality of care in NHs. We examined quality indicator (QI) outcomes for residents in 408 urban New York NHs in July through September, 1995. The QI outcomes studied were restraint and antipsychotic drug use (for low and high-risk residents), and at study commencement, these QIs were being used by the Centers for Medicare and Medicaid Services to monitor the quality of care in USA Medicare and/or Medicaid-certified NHs. A hierarchical modeling approach was used to properly reflect the nesting of both residents within NHs and NHs within counties. Separate regression models were fit to the two strata of interest (Urban Non-Hispanic Whites and Urban African Americans) to test, for each race group, the effect on quality of residing in NHs and counties with higher proportions of African Americans (than state medians). Descriptive analyses found that, compared to Whites, the unadjusted restraint rate was lower for African Americans while the antipsychotic drug rate was higher. For both race groups, multi-level analyses showed residence in for-profit NHs was associated with higher likelihoods of being restrained, and of receiving antipsychotic drugs. Also, for both race groups, residence in NHs with higher proportions of African-Americans was associated with lower likelihoods of being restrained and with higher, statistically nonsignificant, likelihoods of receiving antipsychotic drugs. Higher NH nurse staffing ratios were associated with higher likelihoods of being restrained and with lower likelihoods of antipsychotic drug use (statistically significant for low-risk African-Americans). Findings support the notion that differential care is provided in USA NHs caring for higher proportions of African-American residents and thereby suggest intervention at the organizational level is warranted to improve QI outcomes for both race groups.

Racial disparities in low birthweight and the contribution of residential segregation: a multilevel analysis

This study investigates the geography of racial disparities in low birthweight in New York City by focusing on racial residential segregation and its effect on the risk of low birthweight among African-American infants and mothers. This cross-sectional multilevel analysis uses birth records at the individual level (n=96,882) and racial isolation indices at the census tract or neighborhood level (n=2095) to measure their independent and cross-level effects on low birthweight. This study found that residential segregation and neighborhood poverty operate at different scales to increase the risk of low birthweight. At the neighborhood scale residential segregation is positively and significantly associated with low birthweight, after controlling for individual-level risk factors and neighborhood poverty. Residential segregation explains neighborhood variation in low birthweight means and race effects across census tracts, which cannot be accounted for by neighborhood poverty alone. At the individual scale-increasing levels of residential segregation does not significantly reduce or exacerbate individual-level risk factors for low birthweight; whereas increasing levels of neighborhood poverty significantly eliminates the race effect and reduces the protective effect of being foreign-born on low birthweight, after controlling for other individual-level risk factors and residential segregation. These findings are contradictory to previous health research that shows protective mechanisms associated with ethnic density in local areas. It is likely that structural factors underlying residential segregation, i.e., racial isolation, impose additional stressors on African-American women that may offset or disguise positive attributes associated with ethnic density. However, as poverty is concentrated within these neighborhoods, differences between races in low birthweight cease to exist. This study demonstrates that residential segregation and neighborhood poverty are important determinants of racial disparity in low birthweight in New York City.

Birth outcomes among urban African-American women: a multilevel analysis of the role of racial residential segregation

Residential segregation is a common aspect of the urban experiences of African-Americans in the United States (US), yet few studies have considered how segregation might influence perinatal health. Here, we develop a conceptual model of relationships between segregation and birth outcomes and test the implications of the model in a sample of 434,376 singleton births to African-American women living in 225 US Metropolitan Statistical Areas (MSAs). Data from the National Center for Health Statistics 2002 birth files were linked to data from the 2000 US Census and two distinct measures of segregation: an index of isolation (the probability that an African-American resident will encounter another African-American resident in any random neighborhood encounter) and an index of clustering (the extent to which African-Americans live in contiguous neighborhoods). Using multilevel regression models, controlling for individual- and MSA-level socioeconomic status and other covariates, we found higher isolation was associated with lower birthweight, higher rates of prematurity and higher rates of fetal growth restriction. In contrast, higher clustering was associated with more optimal outcomes. We propose that isolation reflects factors associated with segregation that are deleterious to health including poor neighborhood quality, persistent discrimination and the intra-group diffusion of harmful health behaviors. Associations with clustering may reflect factors associated with segregation that are health-promoting such as African-American political power empowerment, social support and cohesion. Declines in isolation could represent positive steps toward improving birth outcomes among African-American infants while aspects of racial contiguity appear to be mitigating or indeed beneficial. Segregation is a complex multidimensional construct with both deleterious and protective influences on birth outcomes, depending on the dimensions under consideration. Further research to understand racial/ethnic and economic health disparities could benefit from a focus on the contributory role of neighborhood attributes associated with the dimensions segregation and other social geographies.

Area variation in mortality in Tasmania (Australia): the contributions of socioeconomic disadvantage, social capital and geographic remoteness

This study investigated the association between socioeconomic disadvantage, social capital, geographic remoteness and mortality in the Australian state of Tasmania. The analysis is based on death rates among persons aged 25-74 years in 41 statistical local areas (SLA) for the period 1998-2000. Multilevel binomial regression indicated that death rates were significantly higher in disadvantaged areas. There was little support for an association between social capital and mortality, thereby contesting the often held notion that social capital is universally important for explaining variations in population health. Similarly, we found little evidence of a link between geographic remoteness and mortality, which contrasts with that found in other Australian states; this probably reflects the small size of Tasmania, and limited variation in the degree of remoteness amongst its SLA.