Adenoma detection rate in 41,010 patients from Southwest China

Adenoma detection rate (ADR) is considered as an important predictor of the risk of interval colorectal cancer following a screening colonoscopy. A retrospective review of all the patients who underwent colonoscopy in the First Affiliated Hospital of Guangxi Medical University (Nanning, China) between 2003 and 2012 was performed, with the aim of estimating the ADR in Southwest China and determine the effects of age, gender and polyp location on ADR. Demographic information and data regarding the timing of the colonoscopy, number of polyps removed, polyp location and pathological types of polyps were collected and analyzed. The patients were grouped according to colonoscopy date, polyp location, gender and age. The χ² test was used to compare the ADR between the different age and gender groups and the Cochran-Armitage trend test was used to calculate the statistical significance of the ADR trend across age groups. A two-tailed value of P<0.05 was considered to indicate statistically significant differences. A total of 41,010 patients were included, of whom 7,219 were diagnosed with at least one adenoma on pathological examination. Therefore, the ADR value of the 41,010 patients screened in the present study was 17.6%. There was a statistically significant trend of increasing ADR with increasing age in both genders (P<0.05). In addition, the ADR of male patients was significantly higher compared with that of female patients in all age groups (all P<0.05). The ADR of patients aged >50 years was significantly higher compared with that of patients aged <50 years (28.8 vs. 11.0%, respectively; P<0.05). In addition, 20% of the cases of detected adenomas occurred in the rectum, 47% in the left colon and 33% in the right colon.