The Prevalence of Mild Cognitive Impairment in China: Evidence from a Meta-Analysis and Systematic Review of 393,525 Adults

OBJECTIVE: This study aims to precisely determine the prevalence of mild cognitive impairment (MCI) in China, acknowledging its significance as a preclinical stage of dementia and a potential "intervention window." The acceleration of the aging process in China underscores the urgency of this research. METHODS: A comprehensive search was conducted across PubMed, Embase, Web of Science, CNKI, WFD, VIP, and CBM databases from their inception until March 1, 2023. The Agency for Healthcare Research and Quality (AHRQ) methodology checklist guided our quality assessment. A random-effects model meta-analysis was employed to synthesize the pooled prevalence data of MCI in China. RESULTS: Our analysis encompassed 139 studies, incorporating data from 393,525 individuals aged 40 years and above. The studies were predominantly rated as moderate-to-high quality. The overall prevalence of MCI was determined to be 19.6% (95% CI: 17.7-21.6%). Subgroup analyses indicated variations in prevalence: 20.8% (95% CI: 18.9-22.7%) for P-MCI compared to 16.2% (95% CI: 11.7-20.7%) for DSM criteria. Geographically, prevalence in Southern China (21.0%, 95% CI: 18.1-23.9%) exceeded that in Northern China (17.6%, 95% CI: 15.9-19.4%). Notably, prevalence in hospitals (61.7%, 95% CI: 27.8-95.7%) was significantly higher than in nursing homes (16.1%, 95% CI: 14.3-17.9%) and communities (25.3%, 95% CI: 17.4-33.2%), especially after the COVID-19 outbreak. CONCLUSION: The study confirms a 19.6% prevalence rate of MCI in China, influenced by factors such as sample sources, beginning year of survey, and regional differences. It highlights the need for targeted screening and resource allocation to subpopulations at risk, aiming to prevent the progression to dementia.