使用站立时间变异性预测社区居住的老年人的移动障碍：一项前瞻性研究。
Use of stance time variability for predicting mobility disability in community-dwelling older persons: a prospective study.
机构信息
Department of Physical Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
出版信息
J Geriatr Phys Ther. 2012 Jul-Sep;35(3):112-7. doi: 10.1519/JPT.0b013e318243e5f9.
BACKGROUND AND PURPOSE
Mobility disability is a serious and frequent adverse health outcome associated with aging. Early identification of individuals at risk for mobility disability is important if interventions to prevent disability are to be instituted. The objectives of this prospective study were to (1) determine the magnitude of stance time variability (STV) that discriminates individuals who currently have mobility disability (prevalent mobility disability) and (2) determine the magnitude of STV that predicts a new onset of mobility disability at 1 year (incident mobility disability).
METHODS
A total of 552 community-dwelling older adults were evaluated as part of the Cardiovascular Health Study, a longitudinal cohort study. Stance time, in milliseconds, was determined from 2 passes on a 4-m computerized walkway at self-selected walking speed, and STV was defined as the standard deviation from approximately 12 individual steps. Mobility disability was defined as self-reported difficulty walking a one-half mile. Receiver operating characteristic (ROC) curves were plotted to determine an optimal cutoff value for STV for prevalent and incident mobility disability, and the area under the receiver operating characteristic curve (AUC) was computed.
RESULTS
The optimal cutoff score for STV (maximizing sensitivity and specificity) for prevalent mobility disability was 0.037 seconds (sensitivity = 65%, specificity = 65%, AUC = 0.70) and for incident 1-year mobility disability was 0.034 seconds (sensitivity = 61%, specificity = 60%, AUC = 0.65). The use of likelihood ratios demonstrated a gradient of risk across values of STV, with mobility risk increasing as values of STV increased.
DISCUSSION AND CONCLUSION
Values of STV may be useful in identifying older adults with mobility disability and at risk for future disability. We recommend the more conservative estimate for identifying risk, STV = 0.034 seconds, which maximizes the sensitivity and minimizes false negatives. The relatively modest values on the validity indices could possibly be improved by increasing the reliability of the measurement of STV. Clinicians should interpret the cutoff values liberally and use STV in conjunction with other measures until further work is completed to validate STV as an indicator of mobility disability.
背景与目的
行动障碍是与衰老相关的严重且常见的不良健康后果。如果要实施预防残疾的干预措施，早期识别有行动障碍风险的个体很重要。本前瞻性研究的目的是：(1)确定区分目前存在行动障碍（现患行动障碍）和(2)预测 1 年内出现新的行动障碍（新发行动障碍）的站立时间变异性（STV）幅度。
方法
共有 552 名居住在社区的老年人参加了心血管健康研究，这是一项纵向队列研究。站立时间（毫秒）是通过在自我选择的步行速度下使用 4 米长的计算机化步道进行 2 次通过来确定的，STV 定义为大约 12 个单独步骤的标准差。行动障碍定义为自我报告行走半英里有困难。绘制了接收器工作特性（ROC）曲线，以确定 STV 对现患和新发行动障碍的最佳截断值，并计算了接收器工作特性曲线下的面积（AUC）。
结果
STV 对现患行动障碍的最佳截断评分（最大灵敏度和特异性）为 0.037 秒（灵敏度=65%，特异性=65%，AUC=0.70），对 1 年新发行动障碍的最佳截断评分是 0.034 秒（灵敏度=61%，特异性=60%，AUC=0.65）。使用似然比表明，随着 STV 值的增加，风险呈梯度增加。
讨论与结论
STV 值可能有助于识别有行动障碍和未来有残疾风险的老年人。我们建议采用更保守的估计来识别风险，即 STV=0.034 秒，这可以最大限度地提高灵敏度并最大限度地减少假阴性。由于 STV 测量的可靠性有待提高，因此在完成进一步验证 STV 作为行动障碍指标的工作之前，有效性指标的值可能会有所改善。临床医生应该自由地解释截断值，并将 STV 与其他测量值结合使用，直到完成进一步的工作来验证 STV 作为行动障碍的指标。
Zotero 插件