RACE AND GENDER DIFFERENCES IN RESPIRATORY ILLNESS PREVALENCE AND THEIR RELATIONSHIP TO ENVIRONMENTAL EXPOSURES IN CHILDREN 7 TO 14 YEARS OF AGE

Race and gender differences in respiratory illness prevalence rates we re assessed in a cohort of 8,322 white children and 1,056 black childr en 7 to 14 yr of age from four U. S. cities. Boys had higher rates of wheeze, asthma, cough, phlegm, and bronchitis than girls. Black childr en had higher rates of persistent wheeze, shortness of breath with whe eze, asthma, chronic cough, and chronic phlegm than white children. We examined whether the racial disparity in respiratory illness prevalen ce could be accounted for by environmental exposures and socioeconomic factors. The proportion of families without a parent who had graduate d from high school was higher for blacks than for whites, as was the p roportion of single-parent households. Black children took up smoking less frequently; their mothers smoked fewer cigarettes. Personal and m aternal smoking predicted higher rates of persistent wheeze, chronic c ough, chronic phlegm, and chest illness. The relative odds for persist ent wheeze were 1.34 (1.07,1.69) for smoking children compared with no nsmoking children. The relative odds for persistent wheeze were 1,35 ( 1.13,1.60) for children whose mother smoked > 30 cigarettes per day ve rsus children with no maternal smoke exposure. Other predictors of res piratory illnesses included parental respiratory illness, parental edu cation, only-child status, single-parent household, air conditioner us e, and body mass index. Nevertheless, adjustment for socioeconomic fac tors, environmental exposures, and body habitus did not significantly reduce the excess respiratory illness prevalence observed among black children. The adjusted relative odds were 1.47 (1.25, 1.74) for persis tent wheeze and 1.57 (1.17, 2.10) for asthma for black children versus white children. Population differences in unmeasured environmental ex posures or in predisposition to allergy may account for residual diffe rences between black and white children in respiratory illness rates.