The Minimal Important Difference in Physical Activity in Patients with COPD.
The Minimal Important Difference in Physical Activity in Patients with COPD.
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DOI：
10.1371/journal.pone.0154587
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Troosters T
中科院分区：
文献类型：
--
作者：
Demeyer H;Burtin C;Hornikx M;Camillo CA;Van Remoortel H;Langer D;Janssens W;Troosters T
身体活动（PA）的变化很难解释，因为不存在最小重要差异（MID）的框架。我们旨在确定慢性阻塞性肺疾病患者体力活动（PA）的最小重要差异（MID），并通过评估其对首次COPD相关住院时间的影响来临床验证MID。在74例患者康复前和康复后3个月（康复样本）客观测量PA一周。此外，通过连续两周测量PA，在30例患者（重测样本）中测量组内相关系数。选择每日步数作为结果测量。选择不同的分布和基于锚的方法来计算MID。在超过MID的患者和未超过MID的患者之间，比较了因急性加重而首次住院的时间。MID的计算结果为599（测量标准误差）、1029（经验规则效应量）、1072（Cohen效应量）和1131（0.5SD）步。由于缺乏充分相关的锚，无法获得基于锚的估计。以测量标准误作为截止值，超过MID的患者与未超过MID的患者之间的首次入院时间存在显著差异。肺康复后的MID介于600和1100步之间。这一变化的临床重要性得到了改善超过600步的患者住院风险降低的支持。
Changes in physical activity (PA) are difficult to interpret because no framework of minimal important difference (MID) exists. We aimed to determine the minimal important difference (MID) in physical activity (PA) in patients with Chronic Obstructive Pulmonary Disease and to clinically validate this MID by evaluating its impact on time to first COPD-related hospitalization. PA was objectively measured for one week in 74 patients before and after three months of rehabilitation (rehabilitation sample). In addition the intraclass correlation coefficient was measured in 30 patients (test-retest sample), by measuring PA for two consecutive weeks. Daily number of steps was chosen as outcome measurement. Different distribution and anchor based methods were chosen to calculate the MID. Time to first hospitalization due to an exacerbation was compared between patients exceeding the MID and those who did not. Calculation of the MID resulted in 599 (Standard Error of Measurement), 1029 (empirical rule effect size), 1072 (Cohen's effect size) and 1131 (0.5SD) steps.day-1. An anchor based estimation could not be obtained because of the lack of a sufficiently related anchor. The time to the first hospital admission was significantly different between patients exceeding the MID and patients who did not, using the Standard Error of Measurement as cutoff. The MID after pulmonary rehabilitation lies between 600 and 1100 steps.day-1. The clinical importance of this change is supported by a reduced risk for hospital admission in those patients with more than 600 steps improvement.