Chest ACCP Career Connection
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Guest Access | Sign In via User Name/Password
This Article
Right arrow Full Text (PDF) Free
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Article Archive
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lefante, J. J.
Right arrow Articles by Jones, R. N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lefante, J. J.
Right arrow Articles by Jones, R. N.
(Chest. 1996;110:417-421.)
© 1996 American College of Chest Physicians

Adjusting FVC for the Effect of Obstruction

John J. Lefante PhD1; Henry W. Glindmeyer DEngr, FCCP1; Hans Weill MD, FCCP1; and Robert N. Jones MD, FCCP1

1 From the Section of Environmental Medicine, Department of Medicine, Tulane University School of Medicine, New Orleans

Objective: To derive a method of taking into account the effects of obstruction on the FVC, allowing more accurate assessment of other negative ("restrictive") influences.

Design: In 656 subjects with airways obstruction, defined as FEV1/FVC of 0.70 or less, regression of FVC was expressed as percentage of predicted value (FVC %PRED) on potential explanatory variables, including FEV1/FVC. The resulting equation was used to adjust FVC %PRED in 530 other obstructed men, to test whether the adjustment resulted in a different relationship of FVC %PRED to body weight.

Setting: A large occupational respiratory surveillance program utilizing rigorously quality-assured and standardized spirometry.

Subjects: The study included 5,188 men aged 45 to 65 years who denied fibrogenic dust exposures, including 656 with airways obstruction.

Results: There was a significant (p<0.0001) linear relationship between more severe obstruction (lower FEV1/FVC) and lower FVC %PRED. Depending on which of several predictive equations is used, obstruction explains 15 to 17% of variability in FVC %PRED over the entire range of severity of obstruction. Adjusting for obstruction in the separate group of 530 subjects showed a significantly larger effect of body weight on FVC %PRED.

Conclusion: A simple equation can be used to discount the negative effects of obstruction on FVC. This allows more accurate clinical interpretation and can be useful in the analysis of epidemiologic data.

Key Words: epidemiology • obstructive lung disease • restrictive impairment • spirometry

Submitted on November 9, 1995
Accepted on January 21, 1996




This article has been cited by other articles:


Home page
 ChestHome page
S. D. Aaron, R. E. Dales, and P. Cardinal
How Accurate Is Spirometry at Predicting Restrictive Pulmonary Impairment?
Chest, March 1, 1999; 115(3): 869 - 873.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1996 by the American College of Chest Physicians.