The Minimal Important Difference in the 6-Minute Walk Test for Patients with Pulmonary Arterial Hypertension
The Minimal Important Difference in the 6-Minute Walk Test for Patients with Pulmonary Arterial Hypertension
复制标题
DOI：
10.1164/rccm.201203-0480oc
复制
发表时间：
2012-09-01
影响因子：
24.7
通讯作者：
Wise, Robert A.
中科院分区：
文献类型：
--
作者：
Mathai, Stephen C.;Puhan, Milo A.;Wise, Robert A.
理论基础：虽然6分钟步行试验(6MWT)通常被用作肺动脉高压(PAH)临床试验的主要结果指标，但6分钟步行试验(6MWT)的最小重要差异(MID)对于这类患者还没有很好的定义。目的：估计PAH患者6MWT的MID。方法：来自他达拉非治疗PAH的临床试验的研究对象，这是一项为期16周的平行分组随机临床试验，患者接受单纯治疗或接受内皮素受体拮抗剂的背景治疗。6MWT按标准化方案进行。采用分布型和锚定型两种方法估计MID；后者采用《医学结局研究36项简表》(SF-36)中的身体成分总分(PCS)。测量和主要结果：共分析了405名受试者。SF-36的结构域与6MWT有弱到适度的相关性。SF-36的PCS的变化与6MWT的变化最密切相关(r=0.4，P<；0.001)，因此被选为后续基于锚点的分析的锚。分布分析得出的中位数范围为25.1~38.5米，而基于锚点的分析得出的中位数估计为38.6米。结论：使用分布和基于锚点的方法，对PAH的6MWT的估计共识中位数约为33米。这些结果对(1)评估临床试验和特定PAH治疗的荟萃分析的治疗反应，以及(2)为未来的研究设计计算样本量具有重要意义。
Rationale: Although commonly used as the primary outcome measure of clinical trials in pulmonary arterial hypertension (PAH), the minimal important difference (MID) of the 6-minute walk test (6MWT) has not been well defined for this population of patients.Objectives: To estimate the MID in the 6MWT in patients with PAH.Methods: Study subjects from the clinical trial of tadalafil in PAH, a 16-week, parallel-group, randomized clinical trial of patients who were treatment naive or on background therapy with an endothelin receptor antagonist, were eligible. 6MWT was performed using a standardized protocol. Distributional and anchor-based methods were used to estimate the MID; the latter method used the Physical Component Summary Score (PCS) of the Medical Outcomes Study 36-item short form (SF-36).Measurements and Main Results: Four hundred five subjects were analyzed. Domains of the SF-36 were weakly to modestly associated with 6MWT. Change in the PCS of the SF-36 was most strongly associated with change in 6MWT (r = 0.40, P < 0.001) and thus was selected as the anchor for subsequent anchor-based analyses. Distributional analyses yielded estimates of the,MID ranging from 25.1 to 38.5 m, whereas anchor-based analyses yielded an estimate of 38.6 m.Conclusions: Using both distributional and anchor-based methods, the estimated consensus MID in the 6MWT for PAH is approximately 33 m. These results have important implications for (1) assessing treatment responses from clinical trials and metaanalyses of specific PAH therapy, and (2) sample size calculations for future study design.