Division of Bone Diseases, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland.
Gait Posture. 2013 Sep;38(4):1010-4. doi: 10.1016/j.gaitpost.2013.05.015. Epub 2013 Jun 19.
Gait variables may constitute surrogate outcomes for fall risk. Their reliability in a specific population of older fallers has not been fully established, which limits their research and clinical applications. This study aimed to determine test-retest reliability and minimal detectable change (MDC) values for selected fall-related gait variables in older adults with a recent fall history.
Community-dwelling (n=30) and hospitalized (n=30) fallers aged≥65 years were assessed twice using an instrumented pressure-sensitive walkway, under single- and dual-task gait conditions. Intraclass correlation coefficient (ICC(2,1)), standard error of measurement (SEM; SEM%) and MDC at 95% confidence level (MDC95; MDC95%), were used as reliability estimates.
The ICC(2,1) for gait velocity was greater than 0.84 across all gait conditions and groups; SEM% and MDC95% did not exceed 6.5% and 18.1%, respectively. Gait variability measures returned lower ICC(2,1) (range 0.18-0.79), and markedly higher SEM% (16.3-31.9%) and MDC95% (45.3-88.3%). Overall, hospitalized fallers exhibited larger SEM and MDC95 values for variability measures compared to community-dwellers in all gait conditions, while larger values were found for all variables while dual-tasking compared to single-tasking in both groups.
Gait velocity was found to be highly reliable and likely to be sensitive to change over repeated sessions in community-dwelling and hospitalized older fallers, both under single- and dual-task conditions. Gait variability measures showed lower reliability, irrespective of gait condition or group, displaying consistently larger measurement error, particularly under dual-task conditions. Clinicians should consider MDC95 values before using gait variability variables as evaluative outcome measures at patient level.
步态变量可能是跌倒风险的替代结局。它们在特定的老年跌倒人群中的可靠性尚未得到充分确立，这限制了它们在研究和临床中的应用。本研究旨在确定有近期跌倒史的老年跌倒者的特定跌倒相关步态变量的测试-重测信度和最小可检测变化（MDC）值。
使用仪器化压力敏感步态分析系统，在单任务和双任务步态条件下，对 30 名社区居住和 30 名住院跌倒者进行两次评估。采用组内相关系数（ICC(2,1)）、测量误差（SEM；SEM%）和 95%置信水平下的最小可检测变化（MDC95；MDC95%）作为可靠性评估。
所有步态条件和组的步态速度的 ICC(2,1)均大于 0.84；SEM%和 MDC95%分别不超过 6.5%和 18.1%。步态变异性测量的 ICC(2,1)（范围为 0.18-0.79）较低，SEM%（16.3-31.9%）和 MDC95%（45.3-88.3%）明显较高。总体而言，与社区居住者相比，住院跌倒者在所有步态条件下的变异性测量的 SEM 和 MDC95 值更大，而在两组中，与单任务相比，双任务时所有变量的 MDC95 值都更大。
在社区居住和住院的老年跌倒者中，无论是在单任务还是双任务条件下，步态速度均被发现具有高度可靠性，且可能对重复测试中的变化敏感。步态变异性测量的可靠性较低，无论步态条件或组如何，均显示出较大的测量误差，特别是在双任务条件下。临床医生应在将步态变异性变量用作个体患者评估结果指标之前，考虑 MDC95 值。
