Copyright ©ERS Journals Ltd 2009 Reliability of ventilatory parameters during cycle ergometry in multicentre trials in COPD1 Dept of Medicine, Queens University and Kingston General Hospital, 2 Dept of Community Health and Epidemiology, Queens University, Kingston, ON, 4 Centre de Recherche de lHôpital Laval, Université Laval, Québec, QC, Canada, 3 Boehringer Ingelheim GmbH, Ingelheim, and 5 Pulmonary Research Institute at Hospital Grosshansdorf, Center for Pneumology and Thoracic Surgery, Grosshansdorf, Germany. CORRESPONDENCE: D. E. ODonnell, 102 Stuart Street, Kingston, ON, K7L 2V6, Canada. E-mail: odonnell{at}queensu.ca Keywords: Chronic obstructive pulmonary disease, cycle endurance, dyspnoea, exercise testing, lung hyperinflation
Received: November 7, 2008
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 individuals 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
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.
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