In the past, illness and dependence were viewed as inevitable consequences of old age. Now, we understand that there is a difference between age (the passing of chronological time) and ageing (the increased risk of adverse outcomes over time). Over the last 50 years, ‘frailty’ research has established that ageing is heterogeneous, variable and malleable. Significant advances have been made in frailty measurement (description of clinical features and development of clinical models), mechanisms (insights into pathogenesis) and management (development of interventions to reduce and/or prevent progression). Subsequently, the concept of frailty has informed health policy and clinical practice and started to change perceptions of older age held by the general public and the health sector. Here, we overview key achievements in frailty research and clinical practice and highlight the considerable number of known unknowns that may be addressed in the future.

中文翻译：

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虚弱：了解年龄和衰老之间的差异

过去，疾病和依赖被视为老年不可避免的后果。现在，我们了解到年龄（时间的流逝）和衰老（随着时间的推移不良后果的风险增加）之间存在差异。在过去的 50 年里，“虚弱”研究证实衰老是异质的、多变的和可塑的。在衰弱测量（临床特征的描述和临床模型的开发）、机制（对发病机制的洞察）和管理（制定干预措施以减少和/或预防进展）方面取得了重大进展。随后，虚弱的概念为卫生政策和临床实践提供了信息，并开始改变公众和卫生部门对老年人的看法。这里，