A Contrastive Study of Chinese and American Colonoscopy in Two Tertiary Medical Centers

Abstract

Purpose: The aim of this study is to compare the differences in colonoscopy practice and results in Chinese and American populations. Methods: We retrospectively reviewed and analyzed colonoscopy reports from 200 consecutive patients who underwent a complete colonoscopy in August 2008 at the First Affiliated Hospital of Nanchang University, in China, and at Emory University Hospital, in the United States (100 patients from each institution). Results: The average ages of patients undergoing colonoscopy were 45 years (95% CI 42-48) for the Chinese group and 55 years (95% CI 53-57) for the American group. The male to female ratio was not significantly different (p=0.202) between the two groups. Pathological findings, mainly polyps and diverticula, were three times more prevalent in American Group than they were in the Chinese group despite 38% of the American colonoscopies being conducted for screening purposes only. Nineteen percent (19%) of the screening colonoscopies showed normal examinations. In those that showed abnormal results, polyps and diverticula were the most common bowel diseases found in both groups. Age was a significant risk factor for polyps with an odds ratio (OR) of 2.206 in the Chinese group (p=0.017, 95% CI 1.155-4.216) and OR of 1.945 (p=0.042, 95% CI 1.024-3.696) in American group. The peak finding of polyps occurred between the ages of 50 to 70 in both groups. Findings revealed the most common site for colonic polyps was in the distal colon for both groups. Proximal colon polyps were more commonly found in the American group; diverticula occurred predominantly in the proximal colon in the Chinese group. The finding of adenomas increased significantly in patients over age 50 in both the Chinese and American groups, but the ratio in patients over 50 yrs old was significantly higher in the American group than that in the Chinese group (p=0.038). Conclusion: Pathological findings in colonoscopy were significantly more common in American patients than in Chinese patients in this study. Polyps and diverticula were the predominant findings in both groups. Polyps in the proximal colon were more common in the American group while diverticula in the proximal colon were more common in the Chinese group. The finding of adenomas increased significantly in patients over 50 years of age in both groups, especially in the American group, where screening colonoscopies as recommended by current standard of care comprised a greater percentage of the procedures. Though studies with larger patient population are needed, we conclude that it would be beneficial for Chinese patients over the age of 50 to also undergo routine colorectal cancer screening with colonoscopy as part of health maintenance exams.