Gill Stephen, McBurney Helen
School of Physiotherapy, La Trobe University, Bendigo, Victoria 3552, Australia.
Physiother Res Int. 2008 Sep;13(3):141-52. doi: 10.1002/pri.411.
Understanding the reliability of selected measurement tools is a prerequisite to understanding the effects of clinical interventions. The aim of this investigation was to determine the reliability of the 50-Foot Timed Walk (50 FTW) and 30-second Chair Stand Test (30 CST) in subjects awaiting joint replacement surgery of the hip or knee.
Eighty-two subjects participating in a 6-week exercise programme were assessed at baseline, 7 weeks and 15 weeks. Four trials of the 50 FTW and two trials of the 30 CST were completed at each assessment. Eleven trained assessors completed the assessments.
Intra-class correlations were consistently high for the 50 FTW and 30 CST at all assessments. At the baseline assessment, trial 1 was found to be significantly different from subsequent trials for both the 50 FTW and 30 CST. This effect was not evident at the 7-week and 15-week assessments. At the baseline assessment, scores for the 50 FTW became stable after the first trial. Estimates of minimum detectable change indicated that participants needed to change by more than 3.08 seconds and 1.64 stands to be 90% confident that a real change had occurred for the 50 FTW and 30 CST, respectively.
The 50 FTW and 30 CST can be reliable measures of physical performance. However, because we found a practice effect at the baseline assessment, a practice trial should be allowed before data collection begins. Because only two trials of the 30 CST were completed, further research is required to confirm whether scores at the initial assessment become stable on repeated testing.
了解所选测量工具的可靠性是理解临床干预效果的前提。本研究的目的是确定50英尺计时步行测试（50 FTW）和30秒坐立试验（30 CST）在等待髋关节或膝关节置换手术患者中的可靠性。
82名参加为期6周运动计划的受试者在基线、7周和15周时接受评估。每次评估时完成4次50 FTW测试和2次30 CST测试。11名经过培训的评估人员完成评估。
在所有评估中，50 FTW和30 CST的组内相关性始终较高。在基线评估时，发现50 FTW和30 CST的第1次测试与后续测试存在显著差异。在7周和15周评估时，这种效应不明显。在基线评估时，50 FTW的分数在第1次测试后趋于稳定。最小可检测变化估计表明，50 FTW和30 CST的参与者分别需要改变超过3.08秒和1.64次坐立，才能有90%的把握确定发生了真正的变化。
50 FTW和30 CST可以作为身体性能的可靠测量指标。然而，由于我们在基线评估中发现了练习效应，在开始数据收集前应进行一次练习测试。由于30 CST仅完成了2次测试，需要进一步研究以确认初始评估分数在重复测试时是否趋于稳定。
