Analysis of relative risk factors influencing miss rates of colorectal adenomas during colonoscopy / 中华消化内镜杂志

ABSTRACT

Objective To analyze the miss rates of colorectal adenomas during colonoscopy as well as risk factors influencing the adenoma miss rates and to take corresponding measures. Methods A total of 432 patients who underwent index and follow-up colonoscopy in 18 months were randomized and investigated. The results of two colonoscopies were compared and the missed adenomas were defined as the adenomas de-tected only during the second colonoscopy. Miss rates were calculated according to patient-based methods. Chi-square test was used to analyze the relative factors influencing the adenoma miss rate of per-patient. Then the meaningful factors were chosen into the logistic regression model for multiple factors analysis. Results Of 432 patients,116(26. 9%)had missed adenomas on first colonoscopy. Single factor analysis found that the size of adenoma( χ2 = 89. 686,P = 0. 000),the shape of adenoma( χ2 = 68. 488,P = 0. 000),the location of adenoma(χ2 = 77. 055,P = 0. 000)and adenoma tissue types(χ2 = 417. 000,P = 0. 000)were the risk factors for miss rates of colorectal adenomas. Number of polyps(χ2 = 8. 450,P= 0. 038),the organi-zation type of polyp(χ2 = 10. 718,P= 0. 013)and proficiency of colonoscopists(χ2 = 56. 069,P= 0. 000), the quality of bowel preparation(χ2 = 39. 195,P = 0. 000),insertion time(χ2 = 13. 133,P = 0. 001)were also the risk factors for miss rates of colorectal adenomas. Logistic regression analysis showed that the bigger the adenoma size,the less missed adenomas(OR= 0. 341,95%CI0. 173-0. 671). Also,the longer insertion time took,the lower the adenoma miss rate(OR = 0. 987,95% CI0. 981-0. 994). Per-patient miss rates were lower for high-risk adenomas compared with low-risk adenomas(OR = 0. 324,95%CI0. 154-0. 680). Adenomas happening in multiple parts of bowel easily leads to missing(OR= 3. 791,95%CI1. 505-9. 546). Conclusion The missed diagnosis of adenomas is not only significantly associated with features of missed adenomas,but also with skills of colonoscopists,insertion time,and bowel preparation. The key is high-quality index colonoscopy to avoid adenomas missing.