Studnicka M, Frischer T, Neumann M
Pulmologisches Zentrum der Stadt Wien, I. Interne Abteilung, Universitätskinderklinik Wien, Austria.
Pediatr Pulmonol. 1998 Apr;25(4):238-43. doi: 10.1002/(sici)1099-0496(199804)25:4<238::aid-ppul4>3.0.co;2-g.
Lung function (LF) tests are part of many investigations in childhood lung disease. However, individual reproducibility of LF will confound between-subject differences. At the same time, increased LF variability has been linked to respiratory disease. In a sample of 598 children, two LF tests, separated by a 5-min interval, were recorded, and reliability (Rel) of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and maximal expiratory flow at 50% of FVC (MEF50) was determined. Rel was also assessed in children trained and untrained in the performance of LF. To investigate determinants of reproducibility for FEV1, the absolute difference between two repeated tests was calculated. Whenever this difference was > 120 ml, a child was considered to demonstrate excessive variability (poor reproducibility) in FEV1. For volume parameters coefficients of reliability (Crel) were found to be better than for MEF50 (FEV1: 0.96; FVC: 0.94, MEF50: 0.91). In untrained children Crel for FEV1 was only 0.91, but it was increased in subsequent visits (0.98, 0.97, and 0.97 at the second, third, and fourth tests, respectively). Excessive variability in FEV1 was observed in 10% of children and was related to the presence of wheeze [odds ratio (OR) 6.31; 95% confidence interval (CI) 1.78-22.4), shortness of breath (OR 3.14; 95% CI 1.00-9.93), a diagnosis of asthma (OR 6.25; 95% CI 1.76-22.1), and bronchial hyperresponsiveness (OR 4.30; 95% CI 2.07-8.94). We conclude that increased variability of LF is likely to be present in young children not accustomed to the testing procedure and in children with respiratory symptoms. Therefore, before guidelines for LF testing are applied, children should be trained to perform the tests and we should be cautious in the interpretation of test results in children who present with symptoms.
肺功能（LF）测试是儿童肺部疾病诸多检查的一部分。然而，LF的个体可重复性会混淆个体间的差异。同时，LF变异性增加与呼吸系统疾病有关。在598名儿童的样本中，记录了间隔5分钟的两次LF测试，并测定了1秒用力呼气量（FEV1）、用力肺活量（FVC）和FVC的50%时的最大呼气流量（MEF50）的可靠性（Rel）。还对接受过和未接受过LF测试训练的儿童的Rel进行了评估。为了研究FEV1重复性的决定因素，计算了两次重复测试之间的绝对差异。每当这个差异>120毫升时，儿童就被认为在FEV1方面表现出过度变异性（重复性差）。发现容积参数的可靠性系数（Crel）优于MEF50（FEV1：0.96；FVC：0.94，MEF50：0.91）。在未接受训练的儿童中，FEV1的Crel仅为0.91，但在随后的几次检查中有所增加（第二次、第三次和第四次测试时分别为0.98、0.97和0.97）。10%的儿童观察到FEV1存在过度变异性，这与喘息的存在[比值比（OR）6.31；95%置信区间（CI）1.78 - 22.4]、呼吸急促（OR 3.14；95% CI 1.00 - 9.93）、哮喘诊断（OR 6.25；95% CI 1.76 - 22.1）以及支气管高反应性（OR 4.30；95% CI 2.07 - 8.94）有关。我们得出结论，不习惯测试程序的幼儿和有呼吸道症状的儿童可能存在LF变异性增加的情况。因此，在应用LF测试指南之前，应训练儿童进行测试，并且我们在解释有症状儿童的测试结果时应谨慎。
