Faculty Collaboration Database

The value of the forced expiratory time in the physical diagnosis of obstructive airways disease. JAMA 1993 Aug 11;270(6):731-6

Date

08/11/1993

Pubmed ID

8336375

DOI

10.1001/jama.1993.03510060077036

Scopus ID

2-s2.0-0027197473 (requires institutional sign-in at Scopus site)   45 Citations

Abstract

OBJECTIVE: To evaluate the test characteristics of the forced expiratory time (FET) in the diagnosis of obstructive airways disease.

DESIGN: 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.

SETTING: 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.

SUBJECTS: A consecutive sample of patients who were referred to the pulmonary function laboratory from primary care internists, pulmonary physicians, and surgeons.

INTERVENTIONS: None.

MAIN OUTCOME MEASURES: 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.

RESULTS: 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.

CONCLUSIONS: 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.

Author List

Schapira RM, Schapira MM, Funahashi A, McAuliffe TL, Varkey B

Author

Timothy L. McAuliffe PhD Professor in the Psychiatry and Behavioral Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adult
Aged
Aged, 80 and over
Cross-Sectional Studies
Female
Forced Expiratory Flow Rates
Humans
Likelihood Functions
Lung Diseases, Obstructive
Male
Middle Aged
Observer Variation
Sensitivity and Specificity
Spirometry