中国高龄老年人认知能力的衰退轨迹及其队列差异

Decline Trajectories of the Cognitive Function and Cohort Differences among the Chinese Oldest-old

基于中国老龄健康长寿影响因素调查(CLHLS)数据,利用混合效应的多层线性模型,分析了1899~1908、1909~1918及1919~1928年3个出生队列的高龄老年人的认知能力衰退过程。研究发现,高龄老年人的认知能力随着年龄持续降低,在临终前会出现加速衰退趋势。3个队列人群的认知能力衰退轨迹存在显著的队列差异,随着预期寿命的增加,高龄老年人的认知能力衰退进程不断延迟,较晚的出生队列的认知能力优于较早的出生队列。但是,对老年人临终前的认知能力变化的分析发现,较晚出生的队列人群临终前处于认知能力缺损状态的时间更长。此外,老年人的认知能力存在强烈的异质性,具有良好的社会经济环境、健康状态及活跃的行为方式的老年人在认知能力上的表现更佳。

Based on data from the Chinese Longitudinal Healthy Longevity Survey(CLHLS),this study examines the decline of cognitive functions among the Chinese oldest-old born in 1899-1908,1909-1918 and 1919-1928 using hierarchical linear model(HLM).As one ages,his/her cognitive functions continuously decrease,and such decrease accelerates before death.There are significant cohort differences in the decline trajectories of cognitive functions among the oldest-old.For the later-born cohorts with longer life expectancy,the decline of cognitive functions is delayed,and they also have better cognitive functions than the earlier-born.However,the later-born cohorts experience longer periods of cognitive impairments before death.Besides,there is strong heterogeneity in older people,and those with better socioeconomic environments,healthier states,and more active behavioral patterns have better cognitive performance.