Ding Yew Y
Department of Geriatric Medicine & Institute of Geriatrics and Active Ageing, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Republic of Singapore.
Department of Methodology, London School of Economics, WC2A 2AE, Columbia House, Houghton Street, London, UK.
Age (Dordr). 2016 Apr;38(2):47. doi: 10.1007/s11357-016-9903-4. Epub 2016 Apr 8.
Different frailty definitions are suitable for different purposes. When investigating its key multidimensional predictors and effects, narrower definitions of frailty that exclude these elements may be more desirable. For this purpose, candidate physical frailty specifications are constructed and then evaluated on their construct and concurrent validity. For 4638 participants aged 65 to 89 years from wave 2 (2004) of the English Longitudinal Study of Ageing, confirmatory factor analysis is performed to create physical frailty specifications with four indicators (slowness, weakness, exhaustion, and weight loss) and with three indicators (slowness, weakness, and either exhaustion or weight loss). Using derived factor scores, their convergent, discriminant, and concurrent validity are compared. For specifications with four indicators and with three indicators including exhaustion, slowness contributes dominantly to the physical frailty factor. However, with three indicators including weight loss, weakness contributes most. Where represented, weight loss only contributes minimally. Higher factor scores are significantly associated with chronic diseases, functional impairment, and poor self-rated health, although less so for the third specification. Factor scores for the first two specifications have low correlation with psychological and social frailty while those for the third have negligible correlation. Factor scores increase with higher Frailty Index although again less so for the third specification. Minor differences are seen across gender. On account of their convergent, discriminatory, and concurrent validity, physical frailty specifications with four indicators and with three indicators including exhaustion hold promise for use in investigation of frailty pathways involving multidimensional predictors and effects.
不同的衰弱定义适用于不同的目的。在研究其关键的多维度预测因素和影响时，排除这些因素的狭义衰弱定义可能更可取。为此，构建了候选身体衰弱规范，然后对其结构效度和同时效度进行评估。对于来自英国老龄化纵向研究第2波（2004年）的4638名65至89岁的参与者，进行验证性因素分析，以创建具有四个指标（行动迟缓、虚弱、疲惫和体重减轻）和三个指标（行动迟缓、虚弱以及疲惫或体重减轻）的身体衰弱规范。使用导出的因素得分，比较它们的收敛效度、区分效度和同时效度。对于具有四个指标以及包括疲惫的三个指标的规范，行动迟缓对身体衰弱因素的贡献最大。然而，对于包括体重减轻的三个指标的规范，虚弱的贡献最大。在有体重减轻指标的情况下，其贡献最小。较高的因素得分与慢性病、功能障碍和自我健康评价差显著相关，尽管对于第三个规范相关性较小。前两个规范的因素得分与心理和社会衰弱的相关性较低，而第三个规范的相关性可忽略不计。因素得分随衰弱指数升高而增加，尽管第三个规范的增加幅度再次较小。不同性别之间存在细微差异。鉴于其收敛效度、区分效度和同时效度，具有四个指标以及包括疲惫的三个指标的身体衰弱规范有望用于涉及多维度预测因素和影响的衰弱途径研究。
