Edna Bennett Pierce Prevention Research Center, The Pennsylvania State University, University Park, Pennsylvania, USA,
College of Nursing, The Pennsylvania State University, University Park, Pennsylvania, USA.
Gerontology. 2021;67(3):357-364. doi: 10.1159/000513728. Epub 2021 Mar 11.
Current understanding of the psychometric properties of items intended to assess the multidimensional construct of subjective memory (SM) is limited, as longitudinal studies of aging commonly use single items or brief sets of items to assess SM. Investigating how SM items cluster within individuals over time would increase the understanding of how combining these items impacts their utility as an early indicator of cognitive change in the aging trajectory. To address this need, the current study examined the factor structure of a brief set of SM items in an existing longitudinal study focused on cognitive aging at both the within-person and between-person levels.
Data were drawn from the Einstein Aging Study, a longitudinal cohort study of aging (N = 1,239, Mage = 77.51, SD = 5.03; 69.50% white; 24.27% black; 6.23% other). Community-dwelling older adults from an urban area of New York City were interviewed annually. At each wave, participants responded to 6 items intended to assess SM. Items assessed participants' perceived memory decline as well as current memory ability. Multilevel exploratory factor analyses examined which factor solution best fit the data at between-person and within-person levels.
Factor structure of the SM items varied at the two levels. At the within-person level, two factors emerged, whereas at the between-person level, a single factor best represented the SM items. Items assessing perceived declines in memory functioning tended to have similar trajectories, while items assessing current memory ability were less related to change over time.
Items appeared to assess two different dimensions of SM when examining within-person changes in SM across time; however, the item structure suggested no other items covaried systematically within persons over time. In contrast to the conceptualization of SM as a multidimensional construct, our findings suggest that when measuring SM between individuals, SM items tend to capture a single dimension underlying SM. This may be due to the long retrospection period of items assessing perceived memory ability. A single item assessing perceived memory decline in older adults without evidence of objective cognitive impairment may be sufficient to monitor memory change in clinical or research settings.
目前，对旨在评估主观记忆（SM）多维结构的项目的心理计量学特性的了解有限，因为衰老的纵向研究通常使用单个项目或简短的项目集来评估 SM。研究 SM 项目如何随时间在个体内部聚集，将增加对如何组合这些项目的理解，从而将其作为衰老轨迹中认知变化的早期指标的效用。为了满足这一需求，本研究在一项关注认知衰老的现有纵向研究中，从个体内和个体间水平检验了一组简短的 SM 项目的因子结构。
数据来自爱因斯坦衰老研究，这是一项针对衰老的纵向队列研究（N=1239，Mage=77.51，SD=5.03；69.50%为白人；24.27%为黑人；6.23%为其他）。来自纽约市一个城市地区的社区居住的老年人每年接受一次采访。在每一波中，参与者都会回答 6 个旨在评估 SM 的项目。这些项目评估了参与者对记忆衰退的感知以及当前的记忆能力。多层次探索性因素分析检验了在个体间和个体内水平上哪种因素解决方案最适合数据。
SM 项目的因子结构在两个水平上有所不同。在个体内水平上，出现了两个因素，而在个体间水平上，单个因素最能代表 SM 项目。评估记忆功能下降的项目往往具有相似的轨迹，而评估当前记忆能力的项目与随时间的变化相关性较低。
当研究随时间变化的个体内 SM 变化时，项目似乎评估了 SM 的两个不同维度；然而，项目结构表明，在个体内部，没有其他项目随时间系统地协变。与将 SM 概念化为多维结构相反，我们的发现表明，当在个体之间测量 SM 时，SM 项目往往会捕获 SM 下的单个维度。这可能是因为评估当前记忆能力的项目具有较长的回溯期。在没有客观认知障碍的老年人群中，评估感知记忆衰退的单个项目可能足以在临床或研究环境中监测记忆变化。
