Predictors of asthma and persistent wheeze in a national sample of children in the United States. Association with social class, perinatal events, and race.

This study analyzes data from the Second National Health and Nutritional Examination Survey to determine whether black children are more likely to have asthma or wheeze, even after adjusting for environmental and socioeconomic exposures. For children 6 months to 11 yr of age, the unadjusted prevalence for asthma was 3.0% among white children and 7.2% among blacks; prevalence of frequent wheeze was 6.2% among whites and 9.3% among blacks. In a logistic regression model including race, age, and sex, the relative odds (RO) of asthma for black children as compared to white children were 2.5 (95% confidence interval [Cl], 1.9 to 3.4). Other predictors of asthma in a stepwise logistic regression included age, sex (boys versus girls, RO = 1.4), younger maternal age (2 standard deviation [SD] drop in age, RO = 1.4), residence in the central city (RO = 1.6), and family income (RO for the lowest versus highest tertile, RO = 1.7). After adjusting for these risk factors, age and sex, black children still had a 1.7 RO (95% Cl, 1.2 to 2.1) of having asthma. Frequent wheeze was associated with race (black versus white, RO = 1.6), sex (boys versus girls, RO = 1.3), birth weight (2 SD deficit in birth weight, RO = 1.4), and triceps skinfold thickness (increase in odds of asthma for 2 SD increase in skinfold, RO = 1.6). The significant effect of maternal age and birth weight after adjusting for other confounding variables suggests that the in utero environment may be an important determinant of asthma.(ABSTRACT TRUNCATED AT 250 WORDS)