title: Reliability of ventilatory parameters during cycle ergometry in multicentre trials in COPD.
abstract: We studied the distribution profiles and repeatability of key exercise performance parameters in the first large multicentre trials to include these measurements in chronic obstructive pulmonary disease (COPD). After a screening visit, 463 subjects with COPD (mean+/-SD forced expiratory volume in 1 s 43+/-13% predicted) completed two run-in visits before treatment randomisation. At the run-in visits, measurements were conducted at rest, at a standardised time near end-exercise (isotime) and at peak exercise during constant work rate (CWR) cycle tests at 75% of each individual's maximum work capacity. The intraclass correlation coefficient was used to evaluate the test-retest repeatability of measurements of endurance time (ET), inspiratory capacity (IC), ventilation and dyspnoea intensity (Borg scale) during exercise. IC, ventilation and dyspnoea ratings were normally distributed; ET showed rightward skew (median<mean, skewness of 10.9 (much greater than zero)) with 16% of the sample exceeding 1 SD of the mean. ET was highly repeatable across run-in visits: 7.9+/-4.8 and 8.4+/-5.1 min (R = 0.84). IC values at rest, isotime and peak exercise were all highly repeatable (R > or = 0.87). Ventilation was repeatable over the same time-points (R > or = 0.92), as was dyspnoea intensity at isotime (R = 0.79) and at peak exercise (R = 0.81). In conclusion, key perceptual and ventilatory parameters can be reliably measured during CWR cycle exercise in multicentre clinical trials in moderate to very severe COPD.
authors.affiliation: Dept of Medicine, Queen's University and Kingston General Hospital, Kingston, ON, Canada. odonnell@queensu.ca
authors.forename: D E
authors.initials: DE
authors.lastname: O'Donnell
authors.forename: J
authors.initials: J
authors.lastname: Travers
authors.forename: K A
authors.initials: KA
authors.lastname: Webb
authors.forename: Z
authors.initials: Z
authors.lastname: He
authors.forename: Y-M
authors.initials: YM
authors.lastname: Lam
authors.forename: A
authors.initials: A
authors.lastname: Hamilton
authors.forename: S
authors.initials: S
authors.lastname: Kesten
authors.forename: F
authors.initials: F
authors.lastname: Maltais
authors.forename: H
authors.initials: H
authors.lastname: Magnussen
mesh_terms: D000328:Adult; D000368:Aged; D004417:Dyspnea / Q000175:diagnosis; D005080:Exercise Test / Q000592:standards*; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D010991:Plethysmography / Q000592:standards; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis*; D015203:Reproducibility of Results; D012129:Respiratory Function Tests / Q000592:standards*; D013147:Spirometry / Q000592:standards; D014797:Vital Capacity