The Prevalence of Vascular Dementia in China: A Systematic Re-view and Meta-Analysis from 2009-2019

Background: Vascular dementia (VD), as the second-largest type of dementia, is a serious stage of vascular cogni-tive impairment. It is significant to conduct retrospective epidemiological studies to characterize further the disease for public health. This study estimated the prevalence of VD among the population aged 18 yr and older in China. Methods: Epidemiological investigations on VD published in journals and covering the period from 1999 to 2019 were identified manually and online by using Chinese databases (such as Chinese BioMedical Literature Database, Chinese National Knowledge Infrastructure database, Chinese science-technology databases, and the Chinese Wan-fang and Chongqing VIP database) and English databases (such as PubMed, Elsevier Science Bibliographic Data-bases and Cochrane library). Studies were included if the diagnostic criteria for VD are clear and the quality of the included literature was evaluated using the quality evaluation criteria of epidemiological research methods. A ran-dom-effects model was employed according to the statistical test of homogeneity. Results: Twenty-six studies met the inclusion criteria, including 100,923 subjects and 977 VD patients. The pooled prevalence of VD was 0.96% (95% [confidence interval, CI] 0.63%~2.1%). The prevalence of VD increased with increasing age. There was a higher prevalence of VD in the northeast China population, in urban areas and males. Conclusion: We stratified the included studies based on age, location, gender, and geographical distribution for prevalence. The prevalence of VD has slowly risen since 1999. It is obviously different between the North & South and urban &rural districts. While there are many benefits of systematic reviews, the methods presented have inher-ent limitations.