Domain-staged progression of cognitive impairment in older adults: Evidence from China

OBJECTIVE: Cognitive impairment is a significant component of health decline in later life. This study aims to examine the temporal sequence of domain-specific cognitive decline among China's older population, to inform healthcare practitioners for more targeted and timely screening and intervention for dementia. METHODS: Data from the 1998-2018 Chinese Longitudinal Healthy Longevity Survey (CLHLS), a national longitudinal survey of Chinese older adults, were used. Cognitive impairment was measured using the validated Chinese version of the Mini-Mental State Examination (MMSE). Proportional Odds Modeling (POM) was utilized to analyze impairment progressions across domains of cognition, and longitudinal analyses were conducted to ensure empirically robust and temporally validated findings. RESULTS: Findings indicate that the progression of cognitive impairment in older adults is staged across domains: the earliest manifestations appear in language and orientation, followed sequentially by recall, calculation, and registration. Recall and calculation are the first domains to reach complete impairment, while registration, language, and orientation deteriorate subsequently. CONCLUSION: Cognitive decline across multiple domains is staged at older ages. The observed pattern of domain-staged cognitive decline at older ages can enable more targeted screening and interventions to prevent the onset of dementia and delay its progression.