Neighborhood Socioeconomic Status in Relation to Cancer Mortality in the Black Women's Health Study, 1995–2011

Abstract

Neighborhood socioeconomic status has been associated with a range of cancer health outcomes, but longitudinal data in African Americans, who tend to live in more deprived neighborhoods, is lacking. We assessed the relation of neighborhood socioeconomic status (SES) to cancer mortality in a prospective cohort of African American women. Participants enrolled in the Black Women's Health Study in 1995 by completing mailed questionnaires. Exposure information and incident diagnoses are updated through biennial questionnaires. Neighborhood SES was measured by a factor score based on census block group data for 6 indicators of income and education – median household income, median housing value, percent of households receiving interest/dividend/rental income, percent of adults who are college graduates, percent of white-collar workers, and percent of households not headed by a single female. Deaths through 2011 and cause of death were identified through linkage to the National Death Index. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) with control for age, education, marital status, cigarette smoking, physical activity, time spent watching TV, and dietary pattern. Based on 819 cancer deaths that occurred from 1995–2011, neighborhood SES was inversely associated with cancer mortality. The age-adjusted HR for lowest quartile of neighborhood SES relative to highest quartile was 1.63, 95% CI 1.33–2.00; control for covariates reduced the HR to 1.29, 95% CI 1.05–1.60. In analyses restricted to participants with 16 or more years of education, the multivariable HR for lowest relative to highest quartile of neighborhood SES was 1.38 (95% CI 1.01–1.90). Our results suggest that neighborhood SES is associated with an individual's risk of cancer mortality and that the association is mediated in part by diet, physical activity, and sedentary behavior. The finding that this association was present even among college graduates is of particular relevance to African Americans, who are more likely to live in disadvantaged neighborhoods regardless of their individual income or educational attainment.