The prevalence of mild cognitive impairment about elderly population in China: a meta-analysis.

Background: Dementia has been a major public health problem and mild cognitive impairment is considered the pre-dementia syndrome in recent years. However, there has not yet been a systematic analysis of the prevalence of mild cognitive impairment in China.

Objectives: The aim of this study was to analyse the prevalence of mild cognitive impairment among the population aged 60  years and older in China.

Methods: Epidemiological investigations on mild cognitive impairment in China published in journals were identified manually and online by using CBMDISK, ChongqingVIP database and CNKI database. Those reported in English journals were identified using MEDLINE. Selected studies had to describe an original study defined by strict screening and diagnlstic criteria. The fixed effects model or random effects model was employed according to statistical test for homogeneity.

Results: Twenty-two studies were selected, the statistical information of which was collected for systematic analysis. The results showed that the pooled prevalence of MCI for the elderly population was 12.7% (95% CI: 9.7-16.5%). In eastern and western China, the prevalence of MCI was 9.6 and 14.7%, respectively. There was a higher prevalence of MCI in the illiterate elderly population than in those who received years of education.

Conclusions: The prevalence of MCI affected by sex, age,education, which was lower in eastern than that in western China.