Xu X, Niu T, Chen C, Wang B, Jin Y, Yang J, Weiss S T
Program of Population Genetics, Harvard School of Public Health, Boston, MA 02115, USA.
Chest. 2001 Mar;119(3):691-700. doi: 10.1378/chest.119.3.691.
Data from a cross-sectional study were analyzed to examine the association of increased airway responsiveness with physician-diagnosed asthma and persistent wheeze.
Two methods for calculating the provocative dose that decreases the airflow rate by 20% (PD(20)) were used as indexes for increased airway responsiveness: (1) a 20% drop in FEV(1) calculated from baseline FEV(1) (PD(20)b), and (2) a 20% drop in FEV(1) from FEV(1) measurements after inhalation of saline solution (PD(20)s). Both PD(20)b and PD(20)s were measured through induction by varying doses of methacholine.
Anqing, Anhui Province, China.
Study subjects were 8 to 74 years of age and were classified into four groups: children (< 15 years old), young adults (15 to 29 years old), adults (30 to 44 years old), and older adults (> or 5 years old).
The differences in estimated odds ratios of airway hyperresponsiveness with asthma and wheeze, sensitivity and specificity, and coefficients of variation were compared between PD(20)b and PD(20)s. The sample for analysis consisted of 10,284 subjects from 2,663 nuclear families with complete data on wheeze, asthma, and major potential confounding factors.
The prevalence of asthma in this sample was lowest in subjects with no demonstrable PD(20) and had a reverse dose-response relationship with PD(20) across all age groups. Using the receiver operating characteristic, the sensitivity and specificity of the PD(20)s or PD(20)b were found to be almost identical. A similar trend was found for persistent wheeze, although the estimated odds ratios for persistent wheeze appeared slightly smaller than those for physician-diagnosed asthma.
This study demonstrates a dose-response relationship between increased airway responsiveness and asthma and wheeze in this Chinese population. PD(20)s or PD(20)b yielded virtually indistinguishable results, which indicated that either of the two tests could serve as an index of airway hyperresponsiveness.
分析一项横断面研究的数据，以检验气道反应性增加与医生诊断的哮喘及持续性喘息之间的关联。
采用两种计算使气流速率降低20%的激发剂量（PD(20)）的方法作为气道反应性增加的指标：（1）根据基线第一秒用力呼气容积（FEV(1)）计算FEV(1)下降20%（PD(20)b），以及（2）吸入盐水溶液后FEV(1)测量值中FEV(1)下降20%（PD(20)s）。PD(20)b和PD(20)s均通过不同剂量的乙酰甲胆碱诱导测量。
中国安徽省安庆市。
研究对象年龄在8至74岁之间，分为四组：儿童（<15岁）、青年成年人（15至29岁）、成年人（30至44岁）和老年人（>45岁）。
比较PD(20)b和PD(20)s在气道高反应性与哮喘及喘息的估计比值比、敏感性和特异性以及变异系数方面的差异。分析样本包括来自2663个核心家庭的10284名受试者，这些受试者具有关于喘息、哮喘和主要潜在混杂因素的完整数据。
在该样本中，无明显PD(20)的受试者哮喘患病率最低，且在所有年龄组中哮喘患病率与PD(20)呈反向剂量反应关系。使用受试者工作特征曲线，发现PD(20)s或PD(20)b的敏感性和特异性几乎相同。持续性喘息也发现了类似趋势，尽管持续性喘息的估计比值比似乎略小于医生诊断的哮喘。
本研究证明了在该中国人群中气道反应性增加与哮喘及喘息之间存在剂量反应关系。PD(20)s或PD(20)b产生的结果几乎无法区分，这表明两种测试中的任何一种都可作为气道高反应性的指标。
