Neighborhood socioeconomic exposures and early-life wheeze and incident asthma
Zanobetti A, Ryan P, Blossom JC, Coull BA, Brokamp C, Heike G, Johnson CC, Havstad S, Joseph CL, Song Y, Mendonca E, Miller RL, Requia W, Hoepner L, Andrews H, Jackson DJ, Wright A, Beamer P, Lothrop N, Hartert TV, Zoratti EM, Bacharier L, Seroogy C, Gern JE, Visness C, Martinez F, and Gold DR. Neighborhood socioeconomic exposures and early-life wheeze and incident asthma. American Journal of Respiratory and Critical Care Medicine 2020; 201(1).
American Journal of Respiratory and Critical Care Medicine
RATIONALE. Family poverty during childhood may exert persistent adverse effects on health and economic self-sufficiency in later life and lack of neighborhood resources may compound family-level disadvantage. We studied the relation of census tract-level neighborhood characteristics with early-life wheeze at age 1 or 2 and asthma incidence throughout childhood in the NIH Environmental influences on Child Health Outcomes (ECHO)-funded Children's Respiratory and Environmental Workgroup (CREW) U.S. asthma birth cohort consortium. CREW cohorts, many high risk on the basis of parental allergy/asthma history, have wide geographic, temporal and socioeconomic diversity.
METHODS: We examined 9 CREW birth cohorts in 11 locations with harmonized data for wheeze and parental report of doctor-diagnosed asthma. Z-scores for census tract variables, including race, median household income, unemployment, and others, were calculated relative to the US average and standard deviation of all census tracts, and linked to participants' birth record address by census tract and decade of birth. Adjusting for sex and cohort, we applied logistic regression models to estimate odds ratios of wheeze prevalence survival curves and Cox proportional hazard models to estimate hazard ratio of asthma incidence for a 1 unit z-score increase in each census tract-level exposure.
RESULTS: Analyses included 6283 children with asthma and 4969 with wheeze. Among these, 56% reported having any wheeze at age 1 or 2, while report of asthma by age 5 varied widely by cohort, with a median prevalence of 22.7% across cohorts. Higher odds ratio of early-life wheeze were found in areas with: higher % black residents (1.12%, 95% CI: 1.05, 1.18), higher % population below poverty level (1.09%, 95% CI: 1.02, 1.15), higher % population with low income (1.11%, 95% CI: 1.04, 1.19), higher % unemployed population (1.11%, 95% CI: 1.04, 1.18), and higher % population with single parent household (1.19%, 95% CI: 1.12, 1.27). We found similar neighborhood risk factors for asthma incidence. Survival curves for asthma incidence by categories of poverty level revealed asthma incidence earlier in life for children living in census tracts with over 75th percentile of families living in poverty. Early asthma incidence was also observed for children living in areas with % poverty between 25th and 75th percentile, compared to living in less poor areas.
CONCLUSIONS: We observed neighborhood racial/ethnic and socioeconomic disparities in childhood wheeze and asthma Future analyses will examine how neighborhood-level factors interact with family-level SES to influence childhood wheeze and parent-report of doctor-diagnosed asthma.