School of Occupational Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan.
Phys Ther. 2011 Jan;91(1):114-21. doi: 10.2522/ptj.20090126. Epub 2010 Oct 14.
The minimal detectable change (MDC) is the smallest amount of difference in individual scores that represents true change (beyond random measurement error). The MDCs of the Timed "Up & Go" Test (TUG) and the Dynamic Gait Index (DGI) in people with Parkinson disease (PD) are largely unknown, limiting the interpretability of the change scores of both measures.
The purpose of this study was to estimate the MDCs of the TUG and the DGI in people with PD.
This investigation was a prospective cohort study.
Seventy-two participants were recruited from special clinics for movement disorders at a university hospital. Their mean age was 67.5 years, and 61% were men. All participants completed the TUG and the DGI assessments twice, about 14 days apart. The MDC was calculated from the standard error of measurement. The percentage MDC (MDC%) was calculated as the MDC divided by the mean of all scores for the sample. Furthermore, the intraclass correlation coefficient was used to examine the reproducibility between testing sessions (test-retest reliability).
The respective MDC and MDC% of the TUG were 3.5 seconds and 29.8, and those of the DGI were 2.9 points and 13.3. The test-retest reliability values for the TUG and the DGI were high; the intraclass correlation coefficients were .80 and .84, respectively.
The study sample was a convenience sample, and the participants had mild to moderately severe PD.
The results showed that the TUG and the DGI have generally acceptable random measurement error and test-retest reliability. These findings should help clinicians and researchers determine whether a change in an individual patient with PD is a true change.
最小可检测变化（MDC）是个体得分中代表真实变化（超出随机测量误差）的最小差异量。帕金森病（PD）患者的计时“站起和行走”测试（TUG）和动态步态指数（DGI）的 MDC 大部分未知，限制了这两种测量方法的变化得分的可解释性。
本研究旨在估计 PD 患者 TUG 和 DGI 的 MDC。
这是一项前瞻性队列研究。
从大学医院的运动障碍专科诊所招募了 72 名参与者。他们的平均年龄为 67.5 岁，61%为男性。所有参与者均两次完成 TUG 和 DGI 评估，两次测试间隔约 14 天。MDC 是从测量误差的标准误差计算得出的。百分比 MDC（MDC%）是将 MDC 除以样本所有分数的平均值计算得出的。此外，还使用组内相关系数来检验测试间的可重复性（测试-重测可靠性）。
TUG 的 MDC 和 MDC%分别为 3.5 秒和 29.8，DGI 的 MDC 和 MDC%分别为 2.9 分和 13.3。TUG 和 DGI 的测试-重测可靠性值较高，组内相关系数分别为.80 和.84。
研究样本为方便样本，参与者的 PD 为轻度至中度严重。
结果表明，TUG 和 DGI 具有一般可接受的随机测量误差和测试-重测可靠性。这些发现应该有助于临床医生和研究人员确定 PD 个体患者的变化是否为真实变化。
