Translational Medicine, SickKids Research Institute, Toronto, Ontario, Canada
Institute of Health Policy Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.
Thorax. 2020 Oct;75(10):891-896. doi: 10.1136/thoraxjnl-2020-214817. Epub 2020 Aug 11.
Current reproducibility standards for spirometry were derived using a small adult dataset and may not be optimal for interpretation of repeated measurements of lung function in children.
To define reproducibility limits for forced expiratory volume in 1 s (FEV) change that represent the normal within-subject between-visit variability in healthy children and evaluate these limits as a tool to monitor children with cystic fibrosis (CF).
Repeated FEV measurements (3 months to 5 years apart) from healthy children from the Global Lung Function Initiative data repository were used to derive a conditional change score. Spirometry and clinical data from a CF clinical database was used to verify utility in clinical practice.
A reproducibility change score was derived from 47 938 FEV measures from 7885 healthy children 6-18 years of age. The simple algorithm, which is conditional on the initial measurement, also accounts for age and time interval between measurements. The change score limits of reproducibility were much narrower than currently used cut-offs. Specifically, changes, considered as improvements using either a 12% or 10% relative change from baseline, are too wide for children. In CF, there was overall agreement between different approaches, with the distinct advantage that the change score was not biased by regression to the mean.
Compared with current approaches to interpretation of repeated lung function measurements, the proposed change score was less biased and provides a simple alternative to reduce misinterpretation.
目前的肺活量测定重复性标准是基于一个小型成人数据集得出的，可能并不适合解释儿童肺功能的重复测量。
定义 1 秒用力呼气量（FEV）变化的重复性限值，这些限值代表健康儿童两次就诊之间的个体内正常变异性，并评估这些限值作为监测囊性纤维化（CF）儿童的工具。
使用来自全球肺功能倡议数据存储库的健康儿童的重复 FEV 测量值（相隔 3 个月至 5 年）来推导条件变化分数。使用 CF 临床数据库中的肺活量测定和临床数据来验证其实用性。
从 6-18 岁的 7885 名健康儿童的 47938 次 FEV 测量值中得出了一个可重复性变化分数。该简单算法（基于初始测量值）还考虑了年龄和测量之间的时间间隔。可重复性变化分数的限值比目前使用的截止值窄得多。具体而言，使用 12%或 10%相对于基线的相对变化来考虑的变化，对于儿童来说过于宽泛，被认为是改善。在 CF 中，不同方法之间存在总体一致性，变化分数不受向平均值回归的偏差影响，这是其明显的优势。
与目前解释重复肺功能测量的方法相比，所提出的变化分数的偏差更小，提供了一种简单的替代方法，以减少误解。
