DETERMINANTS OF PERCENT PREDICTED FEV(1) IN CURRENT ASTHMATIC SUBJECTS

We analyzed the determinants of the percent predicted FEV(1) of a larg e group of diagnosed asthmatic subjects in the Tucson Study of Airway Obstructive Diseases. The 261 subjects were 6 to 88 years old, and 150 (57.5 percent) were female. Although 29.1 percent of the subjects wer e current smokers and 24.1 percent were ex-smokers, we found that pack -years of smoking was not related to lung function. In addition, age o f onset of disease, duration of asthma, eosinophil count, serum IgE le vel, and allergy skin test reactivity status did not influence the %FE V(1). We did find that both severity of wheezing and age of the subjec t related significantly to %FEV(1), and an interaction term of these t wo variables replaced wheeze and age in the multiple regression equati on. Current physician-diagnosed chronic bronchitis and the reported se verity of exertional dyspnea also related to %FEV(1).