Núcleo de Assistência, Ensino e Pesquisa em Reabilitação Pulmonar, Universidade do Estado de Santa Catarina, Florianópolis, Santa Catarina, Brazil.
Programa de Pós-Graduação em Ciências do Movimento Humano, Centro de Ciências da Saúde e do Esporte, Universidade do Estado de Santa Catarina, Florianópolis, Santa Catarina, Brazil.
Respir Care. 2021 Feb;66(2):292-299. doi: 10.4187/respcare.08096. Epub 2020 Sep 22.
Test-retest reproducibility of the 6-min step test (6MST) is controversial in patients with COPD because the decision to perform a second test is influenced by interruptions, physiological overload, and the patient's exercise tolerance. The aim of this study was to analyze the reproducibility of performance on the 6MST (ie, number of steps climbed and interruptions) and physiological variables in subjects with COPD, with and without poor exercise tolerance, and with and without interruptions during the test.
Subjects performed 2 6MST (6MST, 6MST) with a minimum of 30 min rest between tests. Physiological variables were assessed with a gas analyzer. Subjects who performed ≤ 78 steps in the 6MST and ≤ 86 steps in the test with the higher number of steps performed (6MST) were considered to have poor exercise tolerance. Subjects were also stratified according to those who interrupted the 6MST and those who did not interrupt the 6MST.
40 subjects (31 men; FEV percent of predicted = 50.4 ± 13.5) participated in the study. The number of steps, interruptions, and physiological variables showed moderate to high reliability (intraclass correlation coefficient: 0.70-0.99, < .001). Thirty-one (77.5%) subjects had a better performance during 6MST than 6MST (mean difference: 4.65 ± 5.59, < .001). Although the number of times subjects were interrupted was similar between the 2 tests ( = .66), the duration of these interruptions was shorter during 6MST (mean difference: -0.12 ± 0.39 s, = .040). The difference in the number of steps (6MST - 6MST) did not differ between subjects who performed ≤78 steps (mean difference: 5.64 ± 5.32 steps; 10.3%; < 0.001) and ≥ 79 steps (3.00 ± 5.82 steps; 6.13%; = 0.08) on the 6MST ( = 0.15) and between subjects who performed ≤ 86 steps (5.39 ± 5.14 steps; 9.39%; < 0.001) and ≥ 87 steps (2.92 ± 6.43 steps; 2.74%; = 0.14) steps on the 6MST ( = 0.20).
Performance and physiological variables in the 6MST were reproducible, and a second test did not impose greater physiological overload. Two tests were essential for patients with poor exercise tolerance.
在 COPD 患者中，6 分钟台阶试验（6MST）的重测再现性存在争议，因为进行第二次测试的决定受到中断、生理过载和患者运动耐量的影响。本研究的目的是分析 COPD 患者在有和没有中断、运动耐量差和运动耐量好的情况下，6MST（即攀爬的台阶数和中断次数）和生理变量的再现性。
受试者在两次 6MST（6MST1、6MST2）之间至少休息 30 分钟。使用气体分析仪评估生理变量。在 6MST 中完成≤78 步和在完成台阶数较多的测试（6MST）中完成≤86 步的受试者被认为运动耐量差。受试者还根据中断 6MST 和未中断 6MST 的情况进行分层。
40 名受试者（31 名男性；FEV%预测值=50.4±13.5）参与了研究。台阶数、中断次数和生理变量的可靠性为中等到高度（组内相关系数：0.70-0.99，<0.001）。31 名（77.5%）受试者在 6MST 中的表现优于 6MST（平均差异：4.65±5.59，<0.001）。尽管两次测试中受试者被中断的次数相似（=0.66），但在 6MST 中这些中断的持续时间更短（平均差异：-0.12±0.39 s，=0.040）。在 6MST 中完成≤78 步（平均差异：5.64±5.32 步；10.3%；<0.001）和完成≥79 步（3.00±5.82 步；6.13%；=0.08）的受试者之间，以及在 6MST 中完成≤86 步（5.39±5.14 步；9.39%；<0.001）和完成≥87 步（2.92±6.43 步；2.74%；=0.14）的受试者之间，台阶数（6MST-6MST）的差异无统计学意义（=0.15）。
6MST 的表现和生理变量具有可重复性，第二次测试不会造成更大的生理过载。对于运动耐量差的患者，两次测试是必需的。
