Supplementary Material for: The association between frailty and dementia-free and physical disability-free survival in community-dwelling older adults

Introduction: Frailty is a common geriatric syndrome that adversely impacts health outcomes. This study examined correlates of physical frailty in healthy community-dwelling older adults and studied the effect of frailty on disability-free survival (DFS), defined as survival free of independence-limiting physical disability or dementia. Methods: This is a post hoc analysis of 19,114 community-dwelling older adults (median age 74.0 years, interquartile range or IQR: 6.1 years) from Australia and the United States (US) enrolled in the ‘ASPirin in Reducing Events in the Elderly (ASPREE)’ clinical trial. Frailty was assessed using a modified Fried phenotype and a deficit accumulation Frailty Index (FI) utilizing a ratio score derived from 66 items. Multinomial logistic regression was used to examine the correlates of frailty and Cox regression to analyze the association between frailty and DFS (and its components). Results: At study enrollment, 39.0% were pre-frail, and 2.2% of participants were frail, according to Fried phenotype. Older age, higher waist circumference, lower education, ethno-racial origin, current smoking, depression, and polypharmacy were associated with pre-frailty and frailty according to Fried phenotype and FI. Fried phenotype defined pre-frailty and frailty predicted reduced DFS (pre-frail: HR: 1.67; 95%CI: 1.50, 1.86 and frail: HR: 2.80; 95%CI: 2.27, 3.46), affecting each component of DFS including dementia, physical disability and mortality. Effect sizes were larger according to FI. Conclusion: Our study showed that pre-frailty is common in community-dwelling older adults initially free of cardiovascular disease, dementia or independence-limiting physical disability. Pre-frailty and frailty significantly reduced disability-free survival. Addressing modifiable correlates, like depression and polypharmacy, might reduce the adverse impact of frailty on dementia-free and physical disability-free survival.

引言：衰弱（Frailty）是一种常见的老年综合征，会对健康结局产生不利影响。本研究旨在探究社区居住的健康老年人群体中躯体衰弱的相关影响因素，并分析衰弱对无残疾生存（Disability-Free Survival, DFS）的影响——无残疾生存定义为未出现限制自理能力的躯体残疾或痴呆的生存状态。研究方法：本研究为对“老年人群阿司匹林减少事件（ASPirin in Reducing Events in the Elderly, ASPREE）”临床试验的事后分析，共纳入来自澳大利亚与美国的19114名社区居住老年受试者（年龄中位数为74.0岁，四分位间距（IQR）为6.1年）。衰弱评估采用改良Fried表型与缺陷累积衰弱指数（Frailty Index, FI），二者均通过基于66个条目计算的比值得分完成。本研究采用多项logistic回归分析衰弱的相关影响因素，并使用Cox回归分析衰弱与无残疾生存（及其组成部分）之间的关联。研究结果：研究入组时，依据Fried表型判定，39.0%的受试者处于衰弱前期，2.2%的受试者确诊为衰弱。针对Fried表型与衰弱指数的分析结果显示，高龄、更高的腰围、更低的受教育水平、族裔血统、当前吸烟、抑郁以及多重用药与衰弱前期及衰弱显著相关。Fried表型判定的衰弱前期与衰弱均可预测无残疾生存时间缩短（衰弱前期：风险比（HR）1.67；95%置信区间（CI）1.50, 1.86；衰弱组：HR 2.80；95%CI 2.27, 3.46），且会影响无残疾生存的各组成部分，包括痴呆、躯体残疾与死亡。依据衰弱指数计算得到的效应量更大。研究结论：本研究结果显示，在初始无心血管疾病、痴呆或限制自理能力的躯体残疾的社区居住老年人群中，衰弱前期较为常见。衰弱前期与衰弱均可显著缩短无残疾生存时间。针对可干预的相关影响因素（如抑郁与多重用药）采取干预措施，或可减轻衰弱对无痴呆生存与无躯体残疾生存的不良影响。