| pubmed-article:19282342 | pubmed:abstractText | 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. | lld:pubmed |
