title: Issues in pulmonary function testing for the screening and diagnosis of chronic obstructive pulmonary disease.
abstract: OBJECTIVE
  The purpose of this review article is to provide an up-to-date summary on the current evidence for or against the use of lung function tests as screening and diagnostic tools for airflow obstruction in chronic obstructive pulmonary disease (COPD), and to consider the relevant issues in context.
  
  
  RESULTS
  COPD is characterized by chronic respiratory symptoms and airflow limitation with only partial reversibility on lung function testing. However, screening on a population basis or of an enriched 'at-risk' subset like chronic smokers is not supported by findings from previous epidemiological studies, screening trials or in currently published clinical management guidelines by professional societies and review bodies. The definition of airflow obstruction and the classification of disease severity of COPD also differ slightly between guidelines and statements from different professional societies.
  
  
  CONCLUSIONS
  Given the experience from previous screening trials and controversial classification of airflow obstruction by severity, it is impossible to have accurate screening results for COPD based on lung function tests alone. Clinical respiratory symptoms should be taken into consideration in terms of the diagnosis and management of COPD, as well as in any screening trial or programme that is to be attempted or implemented.
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Medicine, University of Hong Kong, Hong Kong SAR, China.
authors.forename: David C L
authors.initials: DC
authors.lastname: Lam
authors.forename: Christopher K M
authors.initials: CK
authors.lastname: Hui
authors.forename: Mary S M
authors.initials: MS
authors.lastname: Ip
mesh_terms: D000367:Age Factors; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D017410:Practice Guidelines as Topic; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D012129:Respiratory Function Tests; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology / Q000503:physiopathology; D014797:Vital Capacity