1 Discipline of Physiotherapy, Faculty of Health Sciences, The University of Sydney, Lidcombe, New South Wales, Australia.
2 Department of Physiotherapy, Sir Charles Gairdner Hospital, Hospital Ave, Nedlands, Western Australia, Australia.
Chron Respir Dis. 2018 May;15(2):131-137. doi: 10.1177/1479972317729051. Epub 2017 Aug 30.
Exercise-induced oxygen desaturation (EID) is prevalent in people with chronic obstructive pulmonary disease (COPD). This article reports a sub-analysis from a randomized controlled trial (RCT) in people with COPD and EID (COPD/EID). The primary aim, in people with COPD/ EID, was to determine the repeatability of the distance and time walked in the incremental shuttle walk test (ISWT) and endurance shuttle walk test (ESWT), respectively. A secondary aim was to determine whether any participant characteristics predicted those who did not demonstrate improvements on a repeat ISWT or ESWT. Participants with nadir oxygen saturation (SpO) < 90% on the 6-minute walk test were recruited to the RCT. Two ISWTs and two ESWTs were then performed as part of the baseline assessments, and participants were included in this sub-analysis if their nadir SpO was <90% during the better of two ISWTs. Repeatability of the tests was analysed using Bland-Altman plots and paired t-tests. Participant characteristics of age, lung function, level of nadir SpO and end-test dyspnoea were used to predict those who were not likely to demonstrate improvements on a repeat test using receiver operating curves. Eighty-seven participants (mean age (standard deviation, SD) 70 (7) years; forced expiratory volume in one second (FEV) 47 (17)% predicted) were included. The mean differences (coefficient of repeatability) for the ISWTs and ESWTs were 9 m (55 m) and 19 seconds (142 seconds) respectively ( p < 0.05). No participant characteristic predicted the absence of improvement on the second ISWT (area under the curve (AUC) ranged from 0.49 to 0.58, all p > 0.2) or the second ESWT (AUC ranged from 0.43 to 0.52, all p > 0.3). Although repeating the tests showed only small improvements in distance (ISWT) and time (ESWT) walked in people with COPD/EID, the variability was large making definite conclusions about test repeatability in these individuals difficult.
运动诱导的血氧饱和度降低（EID）在慢性阻塞性肺疾病（COPD）患者中很常见。本文报道了一项针对 COPD 合并 EID（COPD/EID）患者的随机对照试验（RCT）的亚分析。在 COPD/EID 患者中，主要目的是确定递增式穿梭步行试验（ISWT）和耐力式穿梭步行试验（ESWT）的距离和时间的可重复性。次要目的是确定是否有任何参与者特征可以预测那些在重复 ISWT 或 ESWT 中没有表现出改善的人。招募了在 6 分钟步行试验中出现最低血氧饱和度（SpO）<90%的患者参加 RCT。然后进行了两次 ISWT 和两次 ESWT 作为基线评估的一部分，如果患者在两次 ISWT 中较好的一次中 SpO 最低<90%，则将其纳入本亚分析。使用 Bland-Altman 图和配对 t 检验分析测试的可重复性。参与者的年龄、肺功能、最低 SpO 和终末试验呼吸困难的水平等特征用于使用受试者工作特征曲线预测那些不太可能在重复测试中表现出改善的人。87 名参与者（平均年龄（标准差）70（7）岁；用力呼气量一秒（FEV）47（17）%预计值）被纳入。ISWT 和 ESWT 的平均差异（可重复性系数）分别为 9 m（55 m）和 19 秒（142 秒）（p<0.05）。没有参与者特征可以预测第二次 ISWT（曲线下面积（AUC）范围为 0.49 至 0.58，所有 p>0.2）或第二次 ESWT（AUC 范围为 0.43 至 0.52，所有 p>0.3）中没有改善。尽管在 COPD/EID 患者中重复测试仅显示出距离（ISWT）和时间（ESWT）行走的微小改善，但变异性较大，因此难以对这些个体的测试可重复性做出明确结论。
