Department of Epidemiology, School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
School of Physiotherapy, Dalhousie University, Halifax, Nova Scotia, Canada.
J Am Geriatr Soc. 2024 Jan;72(1):219-225. doi: 10.1111/jgs.18624. Epub 2023 Oct 10.
Higher levels of frailty, quantified by a frailty index (FI), may be linked to fatigue severity as tasks become more physically and mentally demanding. Fatigue, a component of frailty research, has been ambiguous and inconsistent in its operationalization. Fatigability-the quantification of vulnerability to fatigue in relation to specific intensity and duration of activities-offers a more sensitive and standardized approach, though the association between frailty and fatigability has not been assessed.
Using cross-sectional data from the Long Life Family Study at Visit 2 (2014-2017; N = 2524; mean age ± standard deviation (SD) 71.4 ± 11.2 years; 55% women; 99% White), we examined associations between an 83-item FI after excluding fatigue items (ratio of number of health problems reported (numerator) out of the total assessed (denominator); higher ratio = greater frailty) and perceived physical and mental fatigability using the Pittsburgh Fatigability Scale (PFS) (range 0-50; higher scores = greater fatigability).
Participants had mean ± standard deviation FI (0.08 ± 0.06; observed range: 0.0-0.43), PFS Physical (13.7 ± 9.6; 39.5% more severe, ≥15), and PFS Mental (7.9 ± 8.9; 22.8% more severe, ≥13). The prevalence of more severe physical and mental fatigability was higher across FI quartiles. In mixed effects models accounting for family structure, a clinically meaningful 3%-higher FI was associated with 1.9 points higher PFS Physical score (95% confidence interval (CI) 1.7-2.1) and 1.7 points higher PFS Mental score (95% CI 1.5-1.9) after adjusting for covariates.
Frailty was associated with perceived physical and mental fatigability severity. Understanding this association may support the development of interventions to mitigate the risks associated with greater frailty and perceived fatigability. Including measurements of perceived fatigability, in lieu of fatigue, in frailty indices has the potential to alleviate the inconsistencies and ambiguity surrounding the operationalization of fatigue and provide a more precise and sensitive measurement of frailty.
身体虚弱程度的量化指标（衰弱指数，FI）越高，可能与疲劳严重程度有关，因为任务变得更加需要体力和脑力。疲劳是虚弱研究的一个组成部分，其操作性一直存在模糊和不一致。疲劳易感性是一种与特定活动强度和持续时间相关的疲劳易感性的量化方法，提供了一种更敏感和标准化的方法，尽管虚弱和疲劳易感性之间的关联尚未得到评估。
使用来自 Long Life Family Study 的横断面数据（第 2 次就诊（2014-2017 年），N=2524；平均年龄±标准差（SD）71.4±11.2 岁；55%女性；99%白人），我们使用匹兹堡疲劳量表（PFS）（范围 0-50；得分越高，疲劳感越强），检查了在排除疲劳项目后的 83 项 FI（报告的健康问题数量与评估总数的比例（分子）除以分母；比值越高，虚弱程度越大）与感知的身体和精神疲劳易感性之间的关系。
参与者的平均±SD FI（0.08±0.06；观察范围：0.0-0.43），PFS 身体（13.7±9.6；39.5%更严重，≥15）和 PFS 精神（7.9±8.9；22.8%更严重，≥13）。在 FI 四分位数中，身体和精神疲劳易感性更严重的比例更高。在考虑家庭结构的混合效应模型中，FI 高出 3%具有临床意义，与 PFS 身体评分高出 1.9 分（95%置信区间（CI）为 1.7-2.1）和 PFS 精神评分高出 1.7 分（95%CI 为 1.5-1.9）相关，调整了协变量。
虚弱与感知的身体和精神疲劳易感性严重程度相关。了解这种关联可能有助于开发减轻与更大的虚弱和感知疲劳相关的风险的干预措施。在虚弱指数中包含感知疲劳的测量值，而不是疲劳，有可能减轻疲劳操作性的不一致和模糊性，并提供更精确和敏感的虚弱测量。
