The prevalence and incidence of Parkinson's disease in China: a systematic review and meta-analysis.

Parkinson's disease (PD) is a chronic neurodegenerative disorder affecting older individuals. There is inconsistent evidence about the prevalence and incidence of PD in China at present. The aim of the meta-analysis was to estimate the prevalence and incidence of PD and its relation to age, gender, and stage in China. The literature search was conducted using PubMed, EMBASE, Chinese Biological Medical Literature database (CBM), Chinese National Knowledge Infrastructure database (CNKI), Chinese Wanfang and Chongqing VIP database for studies investigating the prevalence and incidence of PD in China from the commencement of the database until August 2012; both English and Chinese publications were included. We estimated the prevalence and incidence of PD using meta-analysis. Thirteen eligible articles were collected. The results showed that the pooled prevalence and incidence of PD were 2 per 100,000 population and 797 per 100,000 person-years. A higher prevalence of PD was found in males than in females (OR 1.29, 95 % CI 1.05-1.57). The prevalence of PD increased with age: the highest was 1,663 per 100,000 in those aged 80 and older. The overall prevalence of PD is lower in China than in developed countries, but the incidence is higher than in some developed countries. Overall, the prevalence of PD appears to increase with age and there are sex differences evident in Chinese individuals.