title: Assessment of functional capacity in patients with chronic obstructive pulmonary disease: correlation between cardiopulmonary exercise, 6 minute walk and 15 step exercise oximetry test.
abstract: BACKGROUND
  Different exercise tests are used to evaluate the functional capacity in chronic obstructive pulmonary disease. The cardiopulmonary exercise test is considered the gold standard, but the 6 minute walk and the 15 step exercise oximetry test are considerably less expensive.
  
  
  OBJECTIVE
  To determine whether reliable data could be obtained at lower cost.
  
  
  METHODS
  The study sample consisted of 50 patients with mild to severe stable COPD. All underwent pulmonary function test and the cardiopulmonary exercise test, 6 minute walk and 15 step exercise oximetry test as part of their regular follow-up visit. Functional capacity was graded according to each test separately and the functional capacities obtained were correlated.
  
  
  RESULTS
  The results showed that most of the patients had severe COPD according to pulmonary function tests (mean forced expiratory volume in the first second 46.3 +/- 19.9% of predicted value). There was a good correlation between the cardiopulmonary exercise test and the 6 minute walk functional capacity classes (r = 0.44, P = 0.0013). We did not find such correlation between the 15 step exercise oximetry test and the cardiopulmonary exercise test (r = 0.07, P = 0.64).
  
  
  CONCLUSIONS
  The study shows that the 6 minute walk is a reliable and accurate test in the evaluation of functional capacity in COPD patients.
authors.affiliation: Pulmonary Institute, Kaplan Medical Center, Rehovot, Israel. daniel_s@clalit.org.il
authors.forename: Daniel
authors.initials: D
authors.lastname: Starobin
authors.forename: Mordechai R
authors.initials: MR
authors.lastname: Kramer
authors.forename: Alexander
authors.initials: A
authors.lastname: Yarmolovsky
authors.forename: Daniel
authors.initials: D
authors.lastname: Bendayan
authors.forename: Izhak
authors.initials: I
authors.lastname: Rosenberg
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Sulkes
authors.forename: Gershon
authors.initials: G
authors.lastname: Fink
mesh_terms: D000328:Adult; D000368:Aged; D005080:Exercise Test / Q000379:methods*; D006801:Humans; D008176:Lung Volume Measurements; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000145:classification*; D012720:Severity of Illness Index; D016138:Walking