University of North Carolina, Chapel Hill.
Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
Arthritis Care Res (Hoboken). 2021 Apr;73(4):559-565. doi: 10.1002/acr.24159.
Little is known regarding what difference in functional performance measures is significant in individuals with chronic medical disease. Our objective was to examine the important differences in gait speed in adults with radiographic knee osteoarthritis.
Functional performance was measured by gait speed using 20-meter and 400-meter walk tests performed at a self-selected usual pace among adults with radiographic knee osteoarthritis participating in the Osteoarthritis Initiative at baseline and 2 years later. Both distribution-based methods and anchor-based methods were used to calculate the important differences in gait speed. Anchor-based methods used the chair stand rate and self-reported function to estimate gait speed differences related to physical function.
We included 2,527 participants with radiographic knee osteoarthritis. Distribution-based important difference estimates for the 20-meter walk ranged from 4.1 to 6.4 meters/minute and 400-meter walk estimates ranged from 2.9 to 6.5 meters/minute. Prevalent (cross-sectional) anchor-based estimates for the 20-meter walk ranged from 5.4 to 6.9 meters/minute and for the 400-meter walk ranged from 3.0 to 6.9 meters/minute. Longitudinal anchor-based estimates were deemed unreliable. Combining distribution-based with prevalent anchor-based methods showed that an important gait speed difference for the 20-meter walk is between 4.1 and 6.9 meters/minute and for the 400-meter walk is between 2.9 and 6.9 meters/minute.
Our results found that the important difference in gait speed for the 20-meter walk and the 400-meter walk is consistent with important difference estimates for older adult populations. These findings can provide benchmarks for assessing and understanding functional performance outcomes when comparing exposure groups and can be used in designing future studies targeting adults with radiographic knee osteoarthritis.
对于患有慢性疾病的个体，功能表现测量的差异有多大具有重要意义，但目前我们对此知之甚少。本研究旨在探讨影像学膝关节骨关节炎患者的步态速度的重要差异。
本研究采用 20 米和 400 米步行测试，以自我选择的通常速度进行，评估影像学膝关节骨关节炎患者的功能表现。20 米和 400 米步行测试的功能表现通过步速来衡量。在基线和 2 年后，我们分别使用基于分布的方法和基于锚定的方法来计算步态速度的重要差异。基于锚定的方法使用椅子站立率和自我报告的功能来估计与身体功能相关的步态速度差异。
我们纳入了 2527 名影像学膝关节骨关节炎患者。20 米步行的分布基础重要差异估计值为 4.1 至 6.4 米/分钟，400 米步行的估计值为 2.9 至 6.5 米/分钟。20 米步行的常见（横断面）锚定估计值为 5.4 至 6.9 米/分钟，400 米步行的估计值为 3.0 至 6.9 米/分钟。纵向锚定估计值被认为不可靠。分布基础与常见锚定方法相结合表明，20 米步行的重要步态速度差异在 4.1 至 6.9 米/分钟之间，400 米步行的差异在 2.9 至 6.9 米/分钟之间。
我们的研究结果发现，20 米和 400 米步行的步态速度重要差异与老年人群的重要差异估计值一致。这些发现可以为比较暴露组时评估和理解功能表现结果提供基准，并可用于针对影像学膝关节骨关节炎患者的未来研究设计。
