Interpretative strategies for lung function tests

This section is written to provide guidance in interpreting pulmonary function tests (PFTs) to medical directors of hospital-based laboratories that perform PFTs, and physicians who are responsible for interpreting the results of PFTs most commonly ordered for clinical purposes.Specifically, this section addresses the interpretation of spirometry, bronchodilator response, carbon monoxide diffusing capacity (DL,CO) and lung volumes.The sources of variation in lung function testing and technical aspects of spirometry, lung volume measurements and DL,CO measurement have been considered in other documents published in this series of Task Force reports [1-4] and in the American Thoracic Society (ATS) interpretative strategies document [5].An interpretation begins with a review and comment on test quality.Tests that are less than optimal may still contain useful information, but interpreters should identify the problems and the