Schapira R M, Schapira M M, Funahashi A, McAuliffe T L, Varkey B
Section of Pulmonary and Critical Care Medicine, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI 53295-1000.
JAMA. 1993 Aug 11;270(6):731-6.
To evaluate the test characteristics of the forced expiratory time (FET) in the diagnosis of obstructive airways disease.
A cross-sectional diagnostic test study. The FET of 400 subjects was measured by a physician examiner and was compared with the criterion standard of spirometry. In a second sample of 100 subjects, the FET was measured by pairs of physician examiners to evaluate interexaminer agreement.
A pulmonary function test laboratory at a tertiary care hospital that receives referrals for preoperative evaluations, acute and chronic pulmonary disease, and occupational lung disease.
A consecutive sample of patients who were referred to the pulmonary function laboratory from primary care internists, pulmonary physicians, and surgeons.
None.
The sensitivity and specificity of the FET in the diagnosis of obstructive airways disease at cutoff values ranging from 2 to 14 seconds. A receiver operating characteristic curve was used to evaluate the diagnostic performance of the FET. Likelihood ratio lines were determined using a logistic regression model adjusting for the subjects age. Interexaminer agreement was evaluated with a kappa statistic.
Using the FET maneuver with a cutoff value of 6 seconds will correctly diagnose the greatest number of subjects with obstructive airways disease. The FET maneuver is more discriminating for subjects 60 years or older compared with younger subjects. The positive likelihood ratio for a subject aged 60 years or older with an FET of 4 to 6 seconds is 0.42 (95% confidence interval [CI], 0.24 to 0.73); of 6 to 8 seconds, 2.19 (95% CI, 1.02 to 4.80); and of greater than 8 seconds, 4.08 (95% CI, 2.54 to 6.79). The kappa statistic for interexaminer agreement is 0.70.
The FET demonstrates moderately good performance as a diagnostic test for obstructive airways disease. The value of the test will depend on the pretest probability of disease and the clinical circumstances in which it is used.
评估用力呼气时间（FET）在诊断阻塞性气道疾病中的检测特性。
一项横断面诊断试验研究。由一名医生检查者测量400名受试者的FET，并与肺活量测定的标准进行比较。在100名受试者的第二个样本中，由成对的医生检查者测量FET，以评估检查者间的一致性。
一家三级护理医院的肺功能测试实验室，接收术前评估、急慢性肺病及职业性肺病的转诊患者。
从初级保健内科医生、肺科医生和外科医生转诊至肺功能实验室的连续样本患者。
无。
FET在诊断阻塞性气道疾病时，截断值范围为2至14秒时的敏感性和特异性。使用受试者工作特征曲线评估FET的诊断性能。使用逻辑回归模型确定似然比线，并对受试者年龄进行校正。用kappa统计量评估检查者间的一致性。
使用截断值为6秒的FET操作可正确诊断出最多数量的阻塞性气道疾病患者。与年轻受试者相比，FET操作对60岁及以上受试者的鉴别能力更强。60岁及以上受试者FET为4至6秒时的阳性似然比为0.42（95%置信区间[CI]，0.24至0.73）；6至8秒时为2.19（95%CI，1.02至4.80）；大于8秒时为4.08（95%CI，2.54至6.79）。检查者间一致性的kappa统计量为0.70。
FET作为阻塞性气道疾病的诊断试验表现出中等良好的性能。该试验的价值将取决于疾病的预检概率及其使用的临床情况。
