title: Reliability of constant-load treadmill testing in patients with intermittent claudication.
abstract: OBJECTIVE
  Constant-load treadmill testing is frequently used to estimate walking ability of patients with peripheral arterial disease and to assess changes in functional capacity following therapeutic interventions or through disease progression. The value of this test has frequently been disputed based on doubts concerning its reproducibility. The aim of this study was to investigate the reliability of treadmill testing at a speed of 3 km/h and a constant inclination of 12%.
  
  
  METHODS
  Sixty-eight patients with stable peripheral arterial disease who were familiar with treadmill testing underwent two sessions of walking exercise at 3 km/h and 12% inclination within three weeks. Initial claudication distance (ICD) and maximum walking distance (MWD) on the treadmill as well as reported walking distances on level ground at individual speed were recorded.
  
  
  RESULTS
  Correlation coefficients of 0.8 and within-subject variation coefficients of 15% for ICD and 13% for MWD demonstrated low variability of walking distances between visits. No learning effects were observed. Intra-class correlation coefficients of 0.78 for ICD and 0.83 for MWD proved good reproducibility of treadmill testing. Correlation of measured and reported walking distances was poor.
  
  
  CONCLUSIONS
  Constant-load treadmill testing at 3km/h and 12% inclination is a well reproducible method to investigate walking capacity of patients with stable intermittent claudication who are familiar with this test method. From treadmill walking distances, no conclusions should be drawn concerning the actual walking range of the patient.
authors.affiliation: Department of Vascular Surgery, Medical University of Innsbruck, Anichstrasse 35, Innsbruck, Austria. Juergen.Falkensammer@i-med.ac.at
authors.forename: J
authors.initials: J
authors.lastname: Falkensammer
authors.forename: S
authors.initials: S
authors.lastname: Gasteiger
authors.forename: B
authors.initials: B
authors.lastname: Polaschek
authors.forename: I
authors.initials: I
authors.lastname: Gruber
authors.forename: A
authors.initials: A
authors.lastname: Frech
authors.forename: G
authors.initials: G
authors.lastname: Fraedrich
authors.forename: M
authors.initials: M
authors.lastname: Schocke
authors.forename: A
authors.initials: A
authors.lastname: Greiner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001317:Austria; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D007383:Intermittent Claudication / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D058729:Peripheral Arterial Disease / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D016138:Walking