Race, socioeconomic factors, and area of residence are associated with asthma prevalence

Asthma prevalence in the United States has been reported to be higher in mi nority groups such as Blacks and Hispanics. Because a disproportionate numb er of individuals from such minority groups are of low socioeconomic status (SES), ii is unclear how much of the racial/ethnic differences in asthma p revalence is related to low SES. We investigated the effect of SES on the r elationship between race/ethnicity and asthma prevalence in a cohort of fam ilies with a history of asthma or allergies from the Boston, Massachusetts area. From 499 families, a cohort of 998 parents and 307 children was ident ified. We used total yearly family income (<$50,000 vs. greater than or equ al to$50,000), highest level of education (less than or equal to high schoo l vs. greater than or equal to college), and residence in high-poverty area s vs, low-poverty areas as measures of SES. Yearly family income <$50,000, less than or equal to high school education, and residence in high poverty areas were all associated with increased ris ks for asthma in both cohorts. In the parental cohort, Blacks and Hispanics (OR = 2.1,95% Cl = 1.5, 2.8; and OR = 2.2, 95% CI = 1.5, 3.2, respectively ) were at greater risk for asthma than Whites. In the cohort of children, B lack and Hispanic children (OR = 2.9, 95% Cl = 1.0, 8.0; and OR = 5.3, 95% Cl = 1.6, 17.5, respectively) were also at increased risk for asthma. When the three measures of SES were included in the multivariable models, the ri sks associated with Blacks and Hispanics decreased in both cohorts. OR = 1. 4, 95% Cl = 0.9, 2.0; and OR = 1.6, 95% Cl = 1.0, 2.6, respectively, for th e parents; and OR = 0.8, 95% Cl = 0.2, 3.0; and 2.5, 95% Cl = 0.5, 11.7, re spectively, for the children. We conclude that a large proportion of the racial/ethnic differences in ast hma prevalence in our study is explained by factors related to income, area of residence, and level of education. (C) 1999 Wiley-Liss, Inc.