Moore Vicky C, Jaakkola Maritta S, Burge Cedd B S G, Robertson Alastair S, Pantin Charles F A, Dev Vellore Arun, Burge P Sherwood
Occupational Lung Disease Unit, Heart of England NHS Trust, Birmingham Heartlands Hospital, Birmingham, UK.
Institute of Occupational and Environmental Medicine, University of Birmingham, Birmingham, UK.
Chest. 2009 Feb;135(2):307-314. doi: 10.1378/chest.08-0778. Epub 2008 Sep 23.
Evidence-based guidelines recommend serial measurements of peak expiratory flow (PEF) on days at and away from work as the first step in the objective confirmation of occupational asthma. The aim of this study was to improve the diagnostic value of computer-based PEF analysis by using the program Oasys-2 to calculate a score from the area between the curves (ABC) of PEF on days at and away from work.
Mean 2-hourly PEFs were plotted separately for workdays and rest days for 109 workers with occupational asthma and 117 control asthmatics. A score based on the ABC was computed from records containing >or= 4 day shifts, >or= 4 rest days, and >or= 6 readings per day. Patients were randomly classified into two data sets (analysis and test sets). Receiver operator characteristic (ROC) curve analysis determined a cutoff point from set 1 that best identified those with occupational asthma, which was then tested in set 2.
Logistic regression analysis showed that all ABC PEF scores were significant predictors of occupational asthma, with the best being ABC per hour from waking (odds ratio, 11.9 per 10 L/h/min; 95% confidence interval, 10.8 to 13.1). ROC curve analysis showed that a difference of 15 L/min/h provided a high specificity without compromising sensitivity in diagnosing occupational asthma. Analysis of data set 2 confirmed a specificity of 100% and sensitivity of 72%.
The ABC PEF score is sensitive and specific for the diagnosis of occupational asthma and can be calculated from a shorter PEF surveillance than is needed for the current Oasys-2 work effect index.
循证指南推荐，在工作日和非工作日对呼气峰值流速（PEF）进行系列测量，作为职业性哮喘客观诊断的第一步。本研究的目的是通过使用Oasys - 2程序计算工作日和非工作日PEF曲线间面积（ABC）的得分，提高基于计算机的PEF分析的诊断价值。
分别绘制了109例职业性哮喘工人和117例对照哮喘患者工作日和休息日每2小时的平均PEF值。从包含≥4个工作日班次、≥4个休息日以及每天≥6次读数的记录中计算基于ABC的得分。患者被随机分为两个数据集（分析集和测试集）。通过受试者工作特征（ROC）曲线分析，从数据集1中确定能最佳识别职业性哮喘患者的临界值，然后在数据集2中进行测试。
逻辑回归分析表明，所有ABC PEF得分都是职业性哮喘的显著预测指标，其中最佳指标是从醒来开始每小时的ABC（优势比为每10L/h/min 11.9；95%置信区间为10.8至13.1）。ROC曲线分析表明，15L/min/h的差值在诊断职业性哮喘时具有高特异性且不影响敏感性。对数据集2的分析证实特异性为100%，敏感性为72%。
ABC PEF得分对职业性哮喘的诊断具有敏感性和特异性，并且与当前Oasys - 2工作效应指数所需的PEF监测相比，可根据更短的PEF监测来计算。
