近年來由於醫療服務及公共衛生普及，國民平均餘命增加，致使台灣邁入高齡化社會。隨著生命的延長，老年人的身心健康功能逐漸衰退，增加了罹患慢性病與失能的機會。本文依據Walker與Avant (1995)之概念分析步驟，針對『失能』進行探討，以其廣泛查證此概念之定義與屬性、並建構範例，確認其前因後果。分析結果發現失能之定義性屬性為：生理或心理失去正常功能，造成日常生活中一種或更多種主要活動的限制，而喪失其獨立生活的能力，以及社會角色功能改變。前因包含疾病、失智、環境因子、意外事件與社會資源運用不當。後果包含身體功能及認知功能喪失、情緒狀態改變、家庭社會功能與生活品質降低，以及社會醫療資源的耗用。鑑於老人失能是現今社會多層面且值得深思重視的議題，因此期望藉由此次概念分析，提升醫療團隊對於失能概念的瞭解，並依據臨床實證評估老年失能程度，運用於護理實務中，做為日後臨床照護與資訊整合的參考。

In the more popular high-quality medical services and public health policy, increasing the average life expectancy of elderly people, Taiwan is an aging country. With a long life, the elderly should be addressed the problem of the gradual decline in physical function and psychological state, and enhance the risk of chronic disease and disability. This article, based on an analysis step by the Walker and Avant (1995), was to explore the definition and validation of elderly disability and construct the examples to confirm the antecedents and consequences of elderly disability. Elderly disability in our analysis reveals that the consequences of physical or mental dysfunctions exist, which lead to one or several limitations of the main activities in daily life then lose abilities to live independently and change in the social role. The defined attributes of antecedents of elderly disability include disease, dementia, environmental factors, accidents and improper use of social resources. The defined attributes of consequences of elderly disability include loss of physical or cognitive function, changes in emotional status, family and social functional status, reduced quality of life, and overuse of social and medical resources. Elderly disability in our society is the most important and multifaceted issue. Therefore, our team would expect these conceptual analyses to promote the understanding of the disabled elderly and apply the empirical assessments for the disabled elderly in the nursing practice and clinical care with the integrated information in the future.