Over the last two decades the impact of neighborhood contexts on the health of their residents has become a major emerging frontier of research in population health and health disparities. Aspects of residential contexts may combine additively or interactively with individual- and household-level variables to significantly increase our ability to explain variation in health outcomes and/or their risk factors, hence offering new avenues for health - promoting interventions. Equally or more important, residential contexts may be key to understanding and reducing persistent social disparities in health by socioeconomic position, and especially race / ethnicity. American society remains quite residentially segregated by race / ethnicity as well as socioeconomic position, and the differential exposures and opportunities associated with such segregation constitute one of the major underexplored areas for understanding and reducing socioeconomic and especially racial/ethnic health disparities.
Research on the health impacts of residential contexts has largely proceeded by linking data from epidemiologic studies of individuals and families with the existing archival data on the areas in which they live, largely derived from Census data at the tract level. Such studies have documented significant associations between contextual variables and individual health outcomes, but the causal nature and specificity of these associations remain limited. We need studies specifically designed from the ground up - in terms of sampling, measurement, and analytic framework - to understand the impact of residential contexts on the health of individuals and households. The Chicago Community Adult Health Study (CCAHS) principally funded by NICHD was designed to characterize not only individuals and households but also neighborhoods, and to analyze the relation between individual / household and neighborhood - level variables.
CCAHS is the only study of a large U.S. city to offer comprehensive assessments of all neighborhoods in a city, which allows researchers to implement spatial analytic models. CCAHS began as a collaborative project with investigators from the Project on Human Development in Chicago Neighborhoods (PHDCN), and it contained modified versions of a community survey that was first administered in the same neighborhoods by PHDCN in 1995 and systematic social observations (SSOs) of blocks within neighborhoods similar to ones that PHDCN conducted in 1995 on a larger number of blocks but in a sub-sample of only 80 neighborhoods. Thus, at the neighborhood-level CCAHS is already a panel data set, containing unique and extensive neighborhood measures that are available in few other studies.
The CCAHS was originally funded as one component of the Michigan Interdisciplinary Center on Social Inequalities, Mind & Body, one of five Mind and Body Centers funded via a special Congressional appropriation to NIH. The original center grant funded the initial collection of survey and observational contextual data for CCAHS between 2001 and 2003 with a response rate of 72%, one of the highest attained in a large urban area over the past decade.
The first wave of the CCAHS consisted of several interrelated components that were conducted simultaneously: (1) a face-to-face survey of adult health for a stratified, multistage, probability sample of 3105 adults, aged 18 and over and living in 343 neighborhood clusters (NCs) within the city of Chicago, including (a) questions that replicate and extend the PHDCN community survey in which individuals described aspects of the social environment of their neighborhoods, as well as (b) direct physical measurements of their blood pressure and heart rate and of height, weight, and waist and hip circumference; (2) systematic social observations (SSOs) of virtually all (1664 of 1672) blocks in which potential survey respondents resided, including a lost- letter drop as an unobtrusive measure of neighborhood social capital/ sense of responsibility to help others; and (3) a biomedical supplement which collected blood and/or saliva samples on a subset of 661 survey respondents in 80 "focal" NCs. The adult health survey and the community survey were conducted jointly via almost two-hour interviews.
The persistence of sizable racial differences in hyper- tension may be due, perhaps entirely, to the different residential contexts in which African Americans are constrained to live. (Morenoff, Jeffrey D., James S. House, Ben B. Hansen, David R. Williams, George A. Kaplan, & Haslyn E. R. Hunte. 2007. "Understanding Social Disparities in Hypertension Prevalence, Awareness, Treatment, & Control: The Role of Neighborhood Context." Social Science &Medicine, 65(9): 1853-1866.)
This study examines the role that residential neighbor- hoods may play in racial/ ethnic & socioeconomic dis- parities in systolic(SBP) & diastolic(DBP) blood pressure, hypertension, & awareness, treatment, & control of hypertension. Between 2001 & 2003 we collected data, including direct assessments of SBP & DBP, on a probability sample of 3105 participants aged 18+ living in 343 Chicago neighborhoods. We found that blacks & people with lower levels of education have significantly higher levels of SBP & higher rates of hypertension than their respective comparison groups (i.e., whites & people with 16+ years of education), but that these disparities diminish & become statistically insignificant after adjusting for neighborhood context. Levels of SBP & DBP & the rate of hypertension were lower in more affluent/ gentrified neighborhoods (i.e., places with a high level of residential turnover & with greater shares of people in their 20s & 30s and/ or have 16+ years of education & are in professional/ managerial occupations), net of controls for a wide range individual- & neighborhood-level controls. Among people with hypertension, blacks were more likely than whites to be aware of their condition, but this difference was also explained by neighborhood factors: people living in more disadvantaged neighborhoods & neighborhoods with greater proportions of blacks were more likely to be aware of their hypertension. Among those being treated for hypertension, blacks were less likely than whites to have their condition under control, & controls for neighborhood context failed to explain this disparity. In sum, residential neighborhoods potentially play a large role in accounting for social disparities in high blood pressure & hypertension prevalence & awareness, but not in treatment for & control of hypertension.
People with impairments in neuromuscular and movement-related functions are more likely to be disabled, in terms of their mobility outdoors, when they live in neighborhoods with poor street and sidewalk quality (as measured by the SSO). (Clarke, Philippa, Jennifer A. Ailshire, Michael Bader, Jeffrey D. Morenoff, and James S. House. 2008. "Mobility Disability and the Urban Built Environment." American Journal of Epidemiology, 168:506-513.)
Research on the effects of the built environment in the pathway from impairment to disability has been largely absent. Using data from the Chicago Community Adult Health Study (2001-2003), we examined the effect of built environment characteristics on mobility disability among adults age 45+ (N=1195) according to their level of lower extremity physical impairment. Built environment characteristics were assessed using systematic social observation to independently rate street and sidewalk quality in the block surrounding each respondentís residence in the City of Chicago. Using multinomial logistic regression we found that street conditions had no effect on outdoor mobility among adults with only mild or no physical impairment. However, among adults with more severe impairment in neuromuscular and movement related functions, the difference in the odd ratios for reporting severe mobility disability was over four times greater when at least one street was in fair or poor condition (characterized by cracks, potholes or broken curbs). When all streets were in good condition the odds of reporting mobility disability was attenuated in those with lower extremity impairment. If street quality could be improved, even somewhat, for those adults at greatest risk for disability in outdoor mobility, the disablement process could be slowed or even reversed.
Dysregulation of the hypothalamic-pituitary-adrenal axis is hypothesized to be an important pathway linking socioeconomic position and chronic disease. This paper tests the association between education and the diurnal rhythm of salivary cortisol. Up to eight measures of cortisol (mean of 5.38 per respondent) over 2 days were obtained from 311 respondents, aged 18-70, drawn from the 2001-2002 Chicago Community Adult Health Study. Multi-level models with linear splines were used to estimate waking level, rates of cortisol decline, and area-under-the-curve over the day, by categories of education. Lower education (0-11 years) was associated with lower waking levels of cortisol, but not the rate of decline of cortisol, resulting in a higher area-under-the-curve for more educated respondents throughout the day. This study found evidence of lower cortisol exposure among individuals with less education and thus does not support the hypothesis that less education is associated with chronic over-exposure to cortisol. (Dowd, Jennifer B., Nalini Ranjit, D. Phuong Do, Elizabeth A. Young, James S. House, and George A.Kaplan. 2010. "Education and Levels of Salivary Cortisol over the Day." Annals of Behavioral Medicine, epub Sept 2,2010)
We are in the process of requesting funding from the National Institutes of Health(NIH) to conduct a second set of interviews in this continuing research project. If funding is obtained, we anticipate contacting participants in 2013-2014.
We have submitted our data to the ICPSR for restricted use by researchers around the world. ICPSR ensures: 1) long-term data availability; 2) worldwide dissemination of data in the major statistical package formats and online analysis; and 3) user support pertaining to downloading and using data;.and 4) It also provides restricted access data service for studies such as CCAHS and a secure data enclave. In addition, ICPSR creates a database of citations based on analyses of the data.