Holland Anne E, Hill Catherine J, Dowman Leona, Glaspole Ian, Goh Nicole, Lee Annemarie L, McDonald Christine F
Department of Physiotherapy
Department of Physiotherapy, La Trobe University, Melbourne, Australia.
Respir Care. 2018 Aug;63(8):994-1001. doi: 10.4187/respcare.05875. Epub 2018 Jun 26.
The aim of this work was to investigate the short- and long-term test-retest reliability of the 6-min walk distance (6MWD), peak heart rate, and nadir oxygen desaturation in idiopathic pulmonary fibrosis (IPF).
A reliability study of 70 adults with IPF was undertaken within out-patient pulmonary rehabilitation programs at 2 tertiary hospitals. Participants completed 2 baseline 6-min walk tests using a standard protocol, with continuous measures of percutaneous S and heart rate via pulse oximetry. The 6-min walk test was completed immediately following an intervention period and 6 months after. Reproducibility was assessed by intraclass correlation coefficient and Bland-Altman analysis.
Participants with a mean ± SD diffusing capacity of the lung for carbon monoxide of 48 ± 14% were included. The reliability of the 6MWD was high (intraclass correlation coefficient = 0.96) with a mean learning effect of 21 m (95% CI 12-30 m). The learning effect persisted at 8 weeks (mean 14 m, 95% CI 5-23 m) but not 6 months (mean 15 m, 95% CI -1 to 30 m). Using the best (greatest) 6MWD significantly reduced the proportion of participants who were classified as having a clinically important response to rehabilitation compared with using the first 6MWD (40% vs 54%, = .002). Nadir S was reproducible, with a mean difference of 0.7 ± 2.2%, and limits of agreement of -4 to 5%. Peak heart rate was more variable, with mean difference 5 ± 9 beats/min and limits of agreement of -12 to 20 beats/min.
The 6MWD is a reproducible measure of exercise capacity in people with IPF. Whereas the nadir S may be accurately determined from one test, evaluating change in 6MWD with interventions may require 2 tests on each occasion. (ClinicalTrials.gov registration NCT0016828.).
本研究旨在调查特发性肺纤维化（IPF）患者6分钟步行距离（6MWD）、心率峰值和最低氧饱和度的短期和长期重测信度。
在两家三级医院的门诊肺康复项目中，对70例成年IPF患者进行了一项信度研究。参与者按照标准方案完成2次基线6分钟步行测试，通过脉搏血氧饱和度仪持续测量经皮血氧饱和度（S）和心率。在干预期结束后立即及6个月后再次完成6分钟步行测试。通过组内相关系数和Bland-Altman分析评估可重复性。
纳入了一氧化碳肺弥散量平均±标准差为48±14%的参与者。6MWD的信度较高（组内相关系数=0.96），平均学习效应为21米（95%CI 12 - 30米）。学习效应在8周时持续存在（平均14米，95%CI 5 - 23米），但在6个月时不存在（平均15米，95%CI -1至30米）。与使用首次6MWD相比，使用最佳（最长）6MWD显著降低了被归类为对康复有临床重要反应的参与者比例（40%对54%，P = 0.002）。最低S是可重复的，平均差异为0.7±2.2%，一致性界限为-4%至5%。心率峰值变异性更大，平均差异为5±9次/分钟，一致性界限为-12至20次/分钟。
6MWD是IPF患者运动能力的可重复测量指标。虽然最低S可通过一次测试准确测定，但评估干预后6MWD的变化可能每次都需要进行2次测试。（ClinicalTrials.gov注册号NCT0016828。）
