Higgins B G, Britton J R, Chinn S, Lai K K, Burney P G, Tattersfield A E
Respiratory Medicine Unit, City Hospital, Nottingham, UK.
Thorax. 1993 Sep;48(9):899-905. doi: 10.1136/thx.48.9.899.
Bronchial reactivity measurements are widely used in epidemiological studies to provide an objective marker of asthma. There are, however, several potential advantages of measuring peak expiratory flow (PEF) variability instead, particularly in large studies. PEF variability and bronchial reactivity were compared in a population sample to assess the relationships of the two measurements to factors known to be associated with airways disease, and to compare their response rates.
Subjects aged 18-65 were randomly selected from the electoral register of an administrative area in eastern England and randomised to attend either for a bronchial challenge test measuring the provocative dose of methacholine producing a 20% fall in FEV1 (PD20), or to measure PEF at two hourly intervals during waking hours for one week. Skin tests with common allergens were performed and a smoking history obtained. PEF variability was expressed as the amplitude % mean (highest - lowest x 100/mean).
A total of 273 subjects (69%) collected a PEF meter but a completed record sheet was returned by only 247 (62%); this was still significantly more than the 202 subjects (54%) who attended for and successfully completed a challenge test. Amplitude % mean was higher in women than in men (9.7% v 8.5%). In multiple regression analysis amplitude % mean increased significantly with age, mean skin weal diameter, and with current smoking. The odds of having a PD20 below 24.5 mumol increased with mean skin weal diameter and were greater in current smokers. Neither age nor sex had a significant effect on bronchial reactivity but there were significant interactions between age and the effects of both smoking and atopy.
The higher response rate associated with the use of PEF variability measurement, and the association with factors implicated in the pathogenesis of airways disease, suggest that PEF variability would be a useful measurement to employ in epidemiological studies.
支气管反应性测量在流行病学研究中被广泛应用，以提供哮喘的客观指标。然而，测量呼气峰值流速（PEF）变异性具有几个潜在优势，特别是在大型研究中。在一个人群样本中比较了PEF变异性和支气管反应性，以评估这两种测量与已知与气道疾病相关因素的关系，并比较它们的反应率。
从英格兰东部一个行政区的选民登记册中随机选取18 - 65岁的受试者，随机分为两组，一组进行支气管激发试验，测量使第一秒用力呼气容积（FEV1）下降20%的乙酰甲胆碱激发剂量（PD20），另一组在清醒时间每两小时测量一次PEF，持续一周。进行常见变应原的皮肤试验并获取吸烟史。PEF变异性以平均幅度百分比表示（最高值 - 最低值×100/平均值）。
共有273名受试者（69%）领取了PEF测量仪，但只有247名（62%）返回了完整的记录表格；这仍显著多于参加并成功完成激发试验的202名受试者（54%）。平均幅度百分比女性高于男性（9.7%对8.5%）。在多元回归分析中，平均幅度百分比随年龄、平均皮肤风团直径和当前吸烟情况显著增加。PD20低于24.5 μmol的几率随平均皮肤风团直径增加，且当前吸烟者更高。年龄和性别对支气管反应性均无显著影响，但年龄与吸烟和特应性效应之间存在显著交互作用。
与使用PEF变异性测量相关的较高反应率，以及与气道疾病发病机制相关因素的关联，表明PEF变异性在流行病学研究中是一种有用的测量方法。
