Six-Minute-Walk Test in Idiopathic Pulmonary Fibrosis Test Validation and Minimal Clinically Important Difference
Six-Minute-Walk Test in Idiopathic Pulmonary Fibrosis Test Validation and Minimal Clinically Important Difference
复制标题
DOI：
10.1164/rccm.201007.1179oc
复制
发表时间：
2011-05-01
影响因子：
24.7
通讯作者：
King, Talmadge E., Jr.
中科院分区：
文献类型：
--
作者：
du Bois, Roland M.;Weycker, Derek;King, Talmadge E., Jr.
理论基础：6分钟步行试验（6MWT）是一种实用且有临床意义的运动耐量测量方法，在各种心肺疾病中具有良好的性能特点。特发性肺纤维化（IPF）患者的表现特征尚未得到系统评价。目的：评估6MWT的可靠性、有效性和反应性，并估计IPF患者的最小临床重要差异（MCID）。方法：研究人群包括在评估干扰素γ -1b的临床试验中完成6MWT的所有受试者（n = 822）。6分钟步行距离（6MWD）和其他参数在基线和24周间隔使用标准化协议进行测量。参数相关系数和分布无关相关系数用于评估6MWD与肺功能、呼吸困难和健康相关生活质量测量之间关系的强度。基于分布的方法和基于锚点的方法对MCID进行了估计。测量结果及主要结果：6MWD（平均间隔24 d）的两种近端测量值的比较显示出良好的信度（系数= 0.83;P < 0.001）。6MWD与生理功能和健康相关生活质量的测量呈弱相关；然而，在功能状态最差的患者中，该值持续且显著降低，表明结构效度良好。重要的是，6MWD的变化可以高度预测死亡率；24周下降大于50米与1年死亡风险增加4倍相关（风险比4.27；95%可信区间2.57-7.10;P < 0.001）。估计MCID为24-45米。结论：6MWT是一种可靠、有效和敏感的疾病状态测量方法，也是IPF临床试验的有效终点。
Rationale: The 6-minute-walk test (6MWT) is a practical and clinically meaningful measure of exercise tolerance with favorable performance characteristics in various cardiac and pulmonary diseases. Performance characteristics in patients with idiopathic pulmonary fibrosis (IPF) have not been systematically evaluated.Objectives: To assess the reliability, validity, and responsiveness of the 6MWT and estimate the minimal clinically important difference (MCID) in patients with IPF.Methods: The study population included all subjects completing a 6MWT in a clinical trial evaluating interferon gamma-1b (n = 822). Six-minute walk distance (6MWD) and other parameters were measured at baseline and at 24-week intervals using a standardized protocol. Parametric and distribution-independent correlation coefficients were used to assess the strength of the relationships between 6MWD and measures of pulmonary function, dyspnea, and health-related quality of life. Both distribution-based and anchor-based methods were used to estimate the MCID.Measurements and Main Results: Comparison of two proximal measures of 6MWD (mean interval, 24 d) demonstrated good reliability (coefficient = 0.83; P < 0.001). 6MWD was weakly correlated with measures of physiologic function and health-related quality of life; however, values were consistently and significantly lower for patients with the poorest functional status, suggesting good construct validity. Importantly, change in 6MWD was highly predictive of mortality; a 24-week decline of greater than 50 m was associated with a fourfold increase in risk of death at 1 year (hazard ratio, 4.27; 95% confidence interval, 2.57-7.10; P < 0.001). The estimated MCID was 24-45 m.Conclusions: The 6MWT is a reliable, valid, and responsive measure of disease status and a valid endpoint for clinical trials in IPF.