支气管反应性的测定已广泛用于流行病学调查。作者在一个小城镇的两组成人受试看中分别用组织胺和乙酰甲胆碱吸入法进行了支气管激发试验的研究,以比较和确定在城镇内研究哪种药物更好.根据Yan等的方法,吸入组织胺和乙酰甲胆碱的量从小量开始逐渐增加到最大剂量分别为4μmol 和12μmol,并测量使FEV_1下降20%(PD_(20))时的用药剂量。在随机分组的108例受试者中比较,乙酰甲胆碱激发组 Bronchial reactivity has been widely used in epidemiological investigations. The authors studied the bronchial provocation test with histamine and methacholine inhalation, respectively, in two groups of adults in a small town to compare and determine which drug is better studied in town. According to Yan et al. , The amount of inhaled histamine and methacholine gradually increased from a small amount to the maximum dose of 4 μmol and 12 μmol, respectively, and the dose of 20% (PD_ (20)) of FEV_1 was measured. Methacholine challenge was compared in 108 randomly assigned subjects