de Morton Natalie A, Davidson Megan, Keating Jennifer L
School of Primary Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia; The Northern Clinical Research Center, Northern Health, Epping, Victoria, Australia.
Physiother Res Int. 2011 Sep;16(3):159-69. doi: 10.1002/pri.493. Epub 2010 Oct 29.
The de Morton Mobility Index (DEMMI) is an instrument that accurately measures the mobility of older people across clinical settings.
To report the multiple reliability studies conducted during the development and validation of the DEMMI.
Intra-rater and inter-rater reliability studies were conducted for the DEMMI in two independent samples (development and validation samples) of older acute medical patients (aged 65 years or older). Inter-rater reliability studies were conducted between the test developer (a physiotherapist) and another experienced physiotherapist. Order of assessor administration was randomized by a coin toss. Patients who were fatigued after the first assessment were excluded from the inter-rater reliability study. Intra-rater reliability studies included participants with 'unchanged' mobility status between hospital admission and discharge. Scale reliability estimates were expressed as the minimal detectable change with 90% confidence (MDC90 ). Item reliability was calculated using Kappa statistics and absolute percentage agreement.
The MDC90 for the DEMMI development sample was 9.51 points (95% confidence interval [95% CI], 5.04-13.32; n=21) and 7.84 (95% CI, 4.34-11.65; n=16) on the 100-point interval DEMMI scale for the inter-rater and intra-rater reliability studies, respectively. Similar estimates were obtained for the DEMMI validation samples of 8.90 (95% CI, 6.34-12.69; n=35) and 13.28 points (95% CI, 8.08-20.87; n=19). Items were not excluded from the DEMMI based on the results of item reliability.
Reliability estimates for the DEMMI were consistent across independent samples of older acute medical patients using different reliability study methodology. Error represents approximately 9% of the DEMMI scale width.
德莫顿运动指数（DEMMI）是一种能够准确测量不同临床环境下老年人运动能力的工具。
报告在DEMMI的开发和验证过程中进行的多项信度研究。
在老年急性内科患者（65岁及以上）的两个独立样本（开发样本和验证样本）中对DEMMI进行了评分者内信度和评分者间信度研究。评分者间信度研究在测试开发者（一名物理治疗师）和另一名经验丰富的物理治疗师之间进行。评估者施测顺序通过抛硬币随机确定。首次评估后感到疲劳的患者被排除在评分者间信度研究之外。评分者内信度研究纳入了入院和出院时运动状态“无变化”的参与者。量表信度估计值以90%置信度的最小可检测变化（MDC90）表示。项目信度使用卡方统计和绝对百分比一致性进行计算。
在100分制的DEMMI量表上，DEMMI开发样本的评分者间信度研究和评分者内信度研究的MDC90分别为9.51分（95%置信区间[95%CI]，5.04 - 13.32；n = 21）和7.84分（95%CI，4.34 - 11.65；n = 16）。DEMMI验证样本的类似估计值分别为8.90分（95%CI，6.34 - 12.69；n = 35）和13.28分（95%CI，8.08 - 20.87；n = 19）。基于项目信度结果，没有项目从DEMMI中被排除。
使用不同信度研究方法，在老年急性内科患者的独立样本中，DEMMI的信度估计是一致的。误差约占DEMMI量表宽度的9%。
