HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Permissions Request Permissions Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Google Scholar Articles by Cerveri, I. Articles by de Marco, R. PubMed PubMed Citation Articles by Cerveri, I. Articles by de Marco, R.

What defines airflow obstruction in asthma?

¹ Division of Respiratory Diseases, IRCCS San Matteo Hospital Foundation, University of Pavia, Pavia. ² Unit of Epidemiology and Medical Statistics, Dept of Medicine and Public Health, University of Verona, Verona, Italy. ³ Centre for Research in Environmental Epidemiology. ⁴ Universitat Pompeu Fabra, ⁵ CIBER en Epidemiología y Salud Pública, ⁶ Institut Municipal d’Investigació Mèdica, ⁷ Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain. ⁸ Dept of Medical Sciences, Respiratory Medicine and Allergology, University of Uppsala, Uppsala, Sweden. ⁹ Dept of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway. ¹⁰ Institute of Epidemiology, GSF National Research Center for Environment and Health, Neuherberg, Germany. ¹¹ Dept of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.

CORRESPONDENCE: A. G. Corsico, Clinica Malattie Apparato Respiratorio, Fondazione IRCCS Policlinico San Matteo, via Taramelli 5, 27100 Pavia, Italy. E-mail: angelo.corsico{at}unipv.it

Keywords: Airflow obstruction, asthma, diagnosis

Received: November 14, 2008
Accepted February 20, 2009

Asthma guidelines from the Global Initiative for Asthma (GINA) and from the National Heart, Lung, and Blood Institute provide conflicting definitions of airflow obstruction, suggesting a fixed forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) cut-off point and the lower limit of normality (LLN), respectively. The LLN was recommended by the recent American Thoracic Society/European Respiratory Society guidelines on lung function testing. The problem in using fixed cut-off points is that they are set regardless of age and sex in an attempt to simplify diagnosis at the expense of misclassification.

The sensitivity and specificity of fixed FEV₁/FVC ratios of 0.70, 0.75 and 0.80 versus the LLN were evaluated in 815 subjects (aged 20–44 yrs) with a diagnosis of asthma within the framework of the European Community Respiratory Health Survey.

In males, the 0.70 ratio showed 76.5% sensitivity and 100.0% specificity, the 0.75 ratio 100.0% sensitivity and 92.4% specificity, and the 0.80 ratio 100.0% sensitivity but 58.1% specificity. In females, the 0.70 ratio showed 57.3% sensitivity and 100.0% specificity, the 0.75 ratio 91.5% sensitivity and 95.9% specificity, and the 0.80 ratio 100.0% sensitivity but 72.9% specificity.

The fixed cut-off points cause a lot of misidentification of airflow obstruction in young adults, with overestimation with the 0.80 ratio and underestimation with the 0.70 ratio. In conclusion, the GINA guidelines should change their criteria for defining airflow obstruction.

This article has been cited by other articles:

				M. R. Miller, O. F. Pedersen, R. Pellegrino, and V. Brusasco Debating the definition of airflow obstruction: time to move on? Eur. Respir. J., September 1, 2009; 34(3): 527 - 528. [Full Text] [PDF]