Supplementary Material for: The Prevalence of Mild Cognitive Impairment in China: Evidence from a meta-analysis and systematic review of 393525 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.

研究目的：本研究旨在精准明确中国轻度认知障碍（Mild Cognitive Impairment, MCI）的患病率，鉴于其作为痴呆临床前期阶段与潜在“干预窗口”的重要意义。伴随中国人口老龄化进程加速，本研究的紧迫性愈发凸显。
研究方法：本研究于2023年3月1日前，全面检索自建库起至该时间点的PubMed、Embase、Web of Science、中国知网（CNKI）、WFD、维普（VIP）及中国生物医学文献数据库（CBM）。研究质量评估采用美国医疗保健研究与质量局（Agency for Healthcare Research and Quality, AHRQ）的方法学核查清单进行指导。本研究采用随机效应模型（random-effects model）Meta分析，以整合中国地区MCI的合并患病率数据。
研究结果：本研究共纳入139项相关研究，涉及393525名40岁及以上受试者的相关数据，且纳入研究的质量大多为中至高等级。中国地区MCI总体患病率为19.6%（95%置信区间：17.7%~21.6%）。亚组分析显示患病率存在差异：采用P-MCI标准的患病率为20.8%（95%置信区间：18.9%~22.7%），而采用DSM诊断标准的患病率为16.2%（95%置信区间：11.7%~20.7%）。地域维度上，中国南方地区MCI患病率（21.0%，95%置信区间：18.1%~23.9%）高于北方地区（17.6%，95%置信区间：15.9%~19.4%）。值得注意的是，医疗机构就诊人群的MCI患病率（61.7%，95%置信区间：27.8%~95.7%）显著高于养老机构（16.1%，95%置信区间：14.3%~17.9%）与社区人群（25.3%，95%置信区间：17.4%~33.2%），这一差异在新冠疫情暴发后尤为明显。
研究结论：本研究证实中国地区MCI患病率为19.6%，该患病率受样本来源、调查起始年份及地域差异等因素影响。本研究强调，需针对高危亚群开展针对性筛查并优化资源配置，以期阻断疾病进展为痴呆。