Forced Vital Capacity in Patients with Idiopathic Pulmonary Fibrosis Test Properties and Minimal Clinically Important Difference
Forced Vital Capacity in Patients with Idiopathic Pulmonary Fibrosis Test Properties and Minimal Clinically Important Difference
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DOI：
10.1164/rccm.201105-0840oc
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发表时间：
2011-12-15
影响因子：
24.7
通讯作者：
Wells, Athol U.
中科院分区：
文献类型：
--
作者：
du Bois, Roland M.;Weycker, Derek;Wells, Athol U.
理由：用力肺活量（FVC）是特发性肺纤维化（IPF）中肺功能的既定指标。在该人群中，关于其测量特性和最小临床重要差异（MCID）的证据有限。目的：评估FVC的信度、效度和反应性，评估IPF患者的MCID。方法：研究人群包括两项IFN-gamma 1b临床试验的所有1156名随机患者。FVC和其他功能状态测量在筛查或基线和之后的24周间隔进行。可靠性评估基于FVC的两个近端测量，有效性评估基于FVC与其他功能状态测量之间的相关性，响应性评估基于24周FVC变化与其他功能状态测量之间的关系。采用基于分布和基于锚点的方法估计MCID。测量值与主要结果：测量值之间的百分比预测FVC相关性高（平均间隔18 d） （r = 0.93; P < 0.001）。植被覆盖度与其他参数的相关性一般较弱，其中植被覆盖度与一氧化碳扩散能力的相关性最强（r = 0.38, P < 0.001）。FVC变化与其他参数变化的相关性稍强（r = 0.16-0.37; P < 0.001）。重要的是，24周FVC下降5%至10%的患者1年死亡风险高出两倍多（P, 0.001）。估计MCID为2-6%。结论：FVC是衡量IPF患者临床状态的可靠、有效和有效的指标，下降2-6%虽然很小，但在临床上具有重要意义。
Rationale: Forced vital capacity (FVC) is an established measure of pulmonary function in idiopathic pulmonary fibrosis (IPF). Evidence regarding its measurement properties and minimal clinically important difference (MCID) in this population is limited.Objectives: To assess the reliability, validity, and responsiveness of FVC and estimate the MCID in patients with IPF.Methods: The study population included all 1,156 randomized patients in two clinical trials of IFN-gamma 1b. FVC and other measures of functional status were measured at screening or baseline and 24-week intervals thereafter. Reliability was assessed based on two proximal measures of FVC, validity was assessed based on correlations between FVC and other measures of functional status, and responsiveness was assessed based on the relationship between 24-week changes in FVC and other measures of functional status. Distribution-based and anchor-based methods were used to estimate the MCID.Measurements and Main Results: Correlation of percent-predicted FVC between measurements(mean interval, 18 d) was high (r = 0.93; P < 0.001). Correlations between FVC and other parameters were generally weak, with the strongest observed correlation between FVC and carbon monoxide diffusing capacity (r = 0.38; P < 0.001). Correlations between change in FVC and changes in other parameters were slightly stronger (range, r = 0.16-0.37; P < 0.001). Importantly, 1-year risk of death was more than twofold higher (P, 0.001) in patients with a 24-week decline in FVC between 5% and 10%. The estimated MCID was 2-6%.Conclusions: FVC is a reliable, valid, and responsive measure of clinical status in patients with IPF, and a decline of 2-6%, although small, represents a clinically important difference.