Neighborhood socioeconomic status predictors of physical activity through young to middle adulthood: The CARDIA study
Research highlights
► Individuals living in deprived neighborhoods in the USA more often have poor health, suggesting neighborhood conditions may influence health.► However, such relationships could arise because certain individual attributes influence both health-related behavior and also residential location.► Our longitudinal analysis addresses whether individual characteristics are related to both selection of neighborhoods and individual health behaviors.► We find that among U.S. black survey respondents, physical activity declined with increased neighborhood deprivation.► Findings suggest that neighborhood deprivation may influence health by limiting physical activity of residents.
Introduction
Neighborhood socioeconomic status (SES) such as census-tract level poverty or composite measures are consistently associated with numerous health outcomes, including mortality (Subramanian, Chen, Rehkopf, Waterman, & Krieger, 2005), general health (Do, 2009), and cardiovascular disease (Diez Roux, Merkin, et al., 2001). Theorized mechanisms by which neighborhood SES influences health (Diez Roux, 2007, Sampson et al., 2002) include mediation by health behaviors through inequitable access to physical activity (PA) opportunities, healthy foods, or health care (structural perspective) or through establishment of social norms (contagion perspective) (Ross, 2000), or direct, cumulative biological effects of chronic stress (Cox et al., 2007, Merkin et al., 2009). While there is an international literature on this topic (e.g., (Boyle et al., 2002, Curtis et al., 2009)), we focus on the U.S., given our study population and the nature of the research question in a U.S. context.
Existing research largely focuses on the influence of neighborhood exposures on broader health outcomes (e.g., neighborhood poverty as a predictor of mortality), rather than on health behaviors (e.g., neighborhood poverty as a predictor of physical activity [PA]). Physical inactivity and obesity are key outcomes related to neighborhood SES (Do et al., 2007, Lee et al., 2007, Wen and Zhang, 2009) and in countries like the U.S. exhibit dramatic racial and socioeconomic disparities (Gordon-Larsen et al., 1999, Ogden et al., 2006) which may result in part from differences in structural (e.g., built environment) (Gordon-Larsen et al., 2006, Moore et al., 2008), contagion, or stress-related factors. While neighborhood SES and physical fitness at a single time point has been examined using the U.S.-based Coronary Artery Risk Development in Young Adults (CARDIA) Study (Shishehbor, Gordon-Larsen, Kiefe, & Litaker, 2008), PA is a modifiable behavior that is amenable to intervention, whereas fitness is influenced by physiological factors.
Additionally, a major limitation of existing research examining neighborhood influences on health and related behaviors is potential bias resulting from self-selection into neighborhoods (Boone-Heinonen et al., 2011, Diez Roux, 2004, Oakes, 2004, van Lenthe et al., 2007). Briefly, factors such as financial resources and household structure (e.g., marital status, children) influence not only where people are able (through affordability or other constraints) or prefer to live (Clark and Ledwith, 2007, Geist and McManus, 2008, Lund, 2006), but also health behaviors (Bell and Lee, 2005, Yannakoulia et al., 2008) and outcomes (Gordon-Larsen et al., 2003, Sobal et al., 2003). Without accounting for factors which influence residential mobility or location decisions, neighborhood SES-health associations could be biased and incorrectly interpreted as neighborhood influence on health. Yet, studies investigating neighborhood influences on PA – which generally stem from the built environment literature (Papas et al., 2007), as opposed to demographic and geographic studies (e.g., (Curtis et al., 2009)) – generally control for individual SES but not other observed characteristics related to residential selection such as marriage and children.
Furthermore, key drivers of residential self-selection may be difficult or impossible to measure. For example, unmeasured characteristics of individuals who are more likely to select a neighborhood with high quality schools (in the U.S., generally in high SES areas) may also influence adoption of physically active lifestyles. Therefore, unmeasured characteristics may bias traditional, covariate-adjusted estimates of how neighborhood SES influences healthy behaviors. In contrast, with longitudinal data, unmeasured characteristics that are stable over time (time-invariant) can be addressed with within-person estimators (e.g., first difference and fixed effects models), which condition on the individual, thereby exploiting variation observed within person, over time (Boone-Heinonen et al., 2011, Do and Finch, 2008, Eid et al., 2008). While within-person estimators do not address dynamic feedback processes in which health may influence subsequent residential selection (Boyle et al., 2002, Curtis et al., 2009), they are uniquely suited to control for unmeasured confounders.
However, few neighborhood health studies have the longitudinal exposure and outcome data necessary to estimate within-person effects. The vast majority of neighborhood health research in the U.S. and elsewhere is cross-sectional, and the few existing longitudinal studies examine general health measures (Do & Finch, 2008) rather than behaviors that might mediate general health, such as PA. In addition, they do not always take advantage of the potentialities of a repeated measures design for addressing unmeasured confounders. Controlling for measured confounders related to residential self-selection and within-person estimation can provide insights into possible causal processes linking neighborhoods and health and into the sensitivity of studies to omission of these unmeasured confounders.
Therefore, we capitalized on longitudinal neighborhood and behavior data from four CARDIA study examinations to investigate how the estimated association between neighborhood SES and PA is influenced by controlling for the confounding effects of (a) measured characteristics related to residential selection in a large body of mobility research (e.g., individual SES, marriage, and children), and (b) unmeasured characteristics which are constant over time.
Section snippets
Study population and data sources
The CARDIA Study is a population-based prospective epidemiologic study of the determinants and evolution of cardiovascular risk factors among black and white young adults. At baseline (1985–6), 5115 eligible subjects, aged 18–30 years, were enrolled with balance according to race (black, white), gender, education (≤ and >high school) and age (18–24 and 25–30 years) from four U.S. communities: Birmingham, Alabama; Chicago, Illinois; Minneapolis, Minnesota; and Oakland, California. Specific
Results
Compared to blacks, whites exhibited substantially higher PA and individual- and neighborhood-level education and income, were more likely to be married, and, except at Year 15, less likely to have children (Table 1, Table 2). Electronic Appendix 1, Table A1.3, available with the online version of the paper, reports neighborhood characteristics within each race-specific neighborhood deprivation quartile.
Among blacks, neighborhood deprivation was related to incrementally lower PA, reaching 27%
Discussion
In one of the first studies to examine the longitudinal relationship between neighborhood SES and PA, we found that in U.S. adults, high neighborhood deprivation was incrementally associated with lower PA in blacks – reaching 16% lower PA for the most vs. least deprived neighborhoods in fully adjusted models – while associations were less consistent in whites. Furthermore, by comparing various strategies to adjust for confounders related to residential selection, we found that adjustment for
Conclusion
After accounting for several potential sources of residential self-selection bias, we found strong estimated longitudinal effects of neighborhood deprivation on lower PA in U.S. blacks but not whites, although racial stratification makes race comparisons problematic. Typical adjustment variables (e.g., individual SES) were the most influential confounders, but time-invariant unmeasured characteristics also appear to contribute bias. Our examination of PA is a first step toward understanding
Acknowledgments
Funding for this study comes from the National Institutes of Health: (R01 HL104580, R01-CA109831, R01-CA121152). Additional funding has come from NIH (R01-AA12162 & DK056350), the UNC-CH Center for Environmental Health and Susceptibility (CEHS) (NIH P30-ES10126), the UNC-CH Clinic Nutrition Research Center (NIH DK56350), and the Carolina Population Center; and from contracts with the University of Alabama at Birmingham, Coordinating Center, N01-HC-95095; University of Alabama at Birmingham,
References (62)
- et al.
The significance of parks to physical activity and public health: a conceptual model
American Journal of Preventive Medicine
(2005) - et al.
Environment and physical activity dynamics: the role of residential self-selection
Psychology of sport and exercise
(2011) - et al.
Does migration exaggerate the relationship between deprivation and limiting long-term illness? A Scottish analysis
Social Science & Medicine
(2002) - et al.
Locality deprivation and type 2 diabetes incidence: a local test of relative inequalities
Social Science & Medicine
(2007) - et al.
Socio-geographic mobility and health status: a longitudinal analysis using the national population health survey of Canada
Social Science & Medicine
(2009) Estimating neighborhood health effects: the challenges of causal inference in a complex world
Social Science & Medicine
(2004)Neighborhoods and health: where are we and where do we go from here?
Revue d’épidémiologie et de Santé Publique
(2007)The dynamics of income and neighborhood context for population health: do long-term measures of socioeconomic status explain more of the black/white health disparity than single-point-in-time measures?
Social Science & Medicine
(2009)- et al.
Neighborhood context and ethnicity differences in body mass index: a multilevel analysis using the NHANES III survey (1988–1994)
Economic Human and Biology
(2007) - et al.
Fat city: questioning the relationship between urban sprawl and obesity
Journal of Urban Economics
(2008)
Sensitive periods and first difference models: integrating etiologic thinking into econometric techniques: a commentary on Clarkwest’s “Neo-materialist theory and the temporal relationship between income inequality and longevity change”
Social Science & Medicine
Adolescent physical activity and inactivity vary by ethnicity: the national longitudinal study of adolescent health
Journal of Pediatr
Interactions, neighborhood selection and housing demand
Journal of Urban Economics
Neighbourhood inequalities in health and health-related behaviour: results of selective migration?
Health & Place
Availability of recreational resources in minority and low socioeconomic status areas
American Journal of Preventive Medicine
The (mis)estimation of neighborhood effects: causal inference for a practicable social epidemiology
Social Scienc & Medicine
Walking, exercising, and smoking: does neighborhood matter?
Social Science & Medicine
Association of neighborhood socioeconomic status with physical fitness in healthy young adults: the coronary artery risk Development in young adults (CARDIA) study
American Heart Journal
Marital status changes and body weight changes: a US longitudinal analysis
Social Science & Medicine
Eating patterns may mediate the association between marital status, body mass index, and blood cholesterol levels in apparently healthy men and women from the ATTICA study
Social Science & Medicine
Association of insulin resistance with distance to wealthy areas: the multi-ethnic study of atherosclerosis
American Journal of Epidemiology
Emerging adulthood and patterns of physical activity among young Australian women
International Journal of Behavior & Medicine
A longitudinal study of physical activity and heart rate recovery: CARDIA, 1987–1993
Medical Science Sports & Exercise
Individual and neighborhood socioeconomic status characteristics and prevalence of metabolic syndrome: the atherosclerosis risk in communities (ARIC) study
Psychosomatic Medicine
How much does income matter in neighborhood choice?
Population Research and Policy Review
Commentary: estimating and understanding area health effects
International Journal of Epidemiology
Availability of recreational resources and physical activity in adults
American Journal of Public Health
Area characteristics and individual-level socioeconomic position indicators in three population-based epidemiologic studies
Annuals of Epidemiology
Neighborhood of residence and incidence of coronary heart disease
The New England Journal of Medicine
The link between neighborhood poverty and health: context or composition?
American Journal of Epidemiology
The built environment, neighborhood crime and constrained physical activity: an exploration of inconsistent findings
Preventive Medicine
Cited by (86)
Lower Rates of Ceramic Femoral Head Use in Non-White Patients in the United States, a National Registry Study
2022, Journal of ArthroplastyGender differences, inequalities and biases in the management of Acute Coronary Syndrome
2022, Journal of Healthcare Quality ResearchCitation Excerpt :Over the last few years there has been more research analysing the characteristics of the places where people live, neighbourhoods and their impact on behavioural, psychosocial and biological factors associated with ACS. Positive associations have been found between a neighborhood's socio-economic status and the incidence of heart disease, as well as with physical exercise, obesity and other risk factors.43 The socio-economic status negatively affects ACS risk, and this concerns more women than men.44,45
Neighborhood Socioeconomic Deprivation in Young Adulthood and Future Respiratory Health: The CARDIA Lung Study
2022, American Journal of Medicine