Handgrip strength accuracy as discriminator of functional independence in centenarian women

Abstract The aim of this study was to verify and compare handgrip strength (HS) with activities of the daily living (ADL) and to identify the cutoff point of HGS in the prediction of independence in ADL of centenarians. Twenty-four centenarians with mean age of 101.67 ± 2.80 years participated in the study. Subjects were asked about marital status, schooling (years), diseases, hearing difficulties and activities of the daily living (Katz scale), to classify functional independence. Handgrip strength of the right hand (HSR) and left hand (HSL) (mean of the three measures of each hand) was evaluated by means of manual dynamometer. The U Mann Whitney test was applied to compare HSR and HSL with functions of ADL. To identify the cutoff point (sensitivity and specificity) of the right and left HGS of centenarians in the prediction of independence in functions of ADL, the Received Operating Characteristic (ROC) Curves were used. The following cutoff points were used: 11 Kgf for HSR (sensitivity = 66.7%, specificity = 100%, ROC curve = 0.778) and 9 Kgf for HSL (sensitivity = 66.7%, specificity = 77.8%, curve ROC = 0.730) to predict independence in performing the "bathing" function; 11 Kgf for HSR for the "continence" function (sensitivity = 83.3%, specificity = 66.7%, ROC curve = 0.712); and 9 Kgf for HSL for "transfer" function (sensitivity = 80%, specificity = 71.4%, ROC curve = 0.786). For these functions, sensitivity and specificity presented values greater than 66%. On all these functions, sensitivity showed values higher than 46% and specificity 77%. Minimum HSR is required to perform functions of ADL independently. The best HSR cutoff point to predict independence of subjects differs according to functions of activities of the daily living and hand evaluated.

摘要 本研究旨在验证并比较握力（handgrip strength, HS）与日常生活活动（activities of daily living, ADL），并确定百岁老人日常生活活动独立性预测中握力的截断值。本研究共纳入24名平均年龄为101.67±2.80岁的百岁老人作为研究对象。研究人员收集了受试者的婚姻状况、受教育年限、患病情况、听力障碍情况以及日常生活活动能力（采用卡茨量表，Katz scale）以评估其功能独立性。通过手持握力计（manual dynamometer）评估受试者右手握力（HSR）与左手握力（HSL，取每只手三次测量的平均值）。采用曼-惠特尼U检验（U Mann Whitney test）比较右手握力、左手握力与日常生活活动功能的差异。为确定百岁老人左右手握力在预测日常生活活动功能独立性中的截断值（含灵敏度与特异度），本研究使用了受试者工作特征（Received Operating Characteristic, ROC）曲线。结果显示，预测"洗澡"功能独立性的截断值为：右手握力11千克力（Kgf），灵敏度66.7%，特异度100%，ROC曲线下面积0.778；左手握力9千克力（Kgf），灵敏度66.7%，特异度77.8%，ROC曲线下面积0.730。预测"二便自控"功能独立性的右手握力截断值为11千克力（Kgf），灵敏度83.3%，特异度66.7%，ROC曲线下面积0.712。预测"体位转移"功能独立性的左手握力截断值为9千克力（Kgf），灵敏度80%，特异度71.4%，ROC曲线下面积0.786。针对上述功能，其灵敏度与特异度均高于66%；所有目标功能的灵敏度均高于46%，特异度均不低于77%。独立完成日常生活活动功能需达到相应最低握力水平。用于预测受试者日常生活活动独立性的最佳握力截断值，会因日常生活活动类型与测试手的不同而存在差异。