The Disease Burden and Clinical Characteristics of Inflammatory Bowel Disease in the Chinese Population: A Systematic Review and Meta-Analysis

The temporal trend of inflammatory bowel disease (IBD) incidence is reported to be increasing in worldwide regions; however, reports focusing on China are sparse. The aim of this study was to provide an overview of the disease burden and clinical features of IBD in the Chinese population. We searched Medline, EMBASE, and another two Chinese databases. A parallel literature review and data extraction were conducted. Meta-analysis was performed to estimate the summary incidence rate of Crohn's disease (CD) and ulcerative colitis (UC). The constituent ratios with 95% CI were calculated for clinical phenotypes and classifications. The literature review included 47 publications. The summary incidence rate of IBD was 1.74 (95% CI: 1.08; 2.40) per 100,000 person years, and the corresponding incidence rates of CD and UC were 0.40 (95% CI: 0.23; 0.57) and 1.18 (95% CI: 0.81; 1.56) per 100,000 person years, respectively. The sex distribution analysis indicated a male predominance in both CD (sex ratio: 1.64; 95% CI: 1.47-1.84) and UC (sex ratio: 1.29; 95% CI: 1.21-1.38). The clinical characteristics were summarized using data from 2283 CD cases and 17,958 UC cases; in which the majority of CD patients were diagnosed between 17-40 years of age, with non-stricturing and non-penetrating disease, varied disease locations, and less extra-intestinal manifestation. UC cases were featured with later disease diagnosis, a more severe disease course, more segmental lesions, and less extra-intestinal manifestations. Our study provided an estimated disease burden of IBD and demonstrated distinct clinical features in the Chinese population. Large-scale population-based studies are needed to further evaluate these findings.