Endoscopist volume and the quality of colonoscopy of the Korean National Cancer Screening Program.

Abstract

6627 Background: The Korean government established the National Cancer Screening Program (KNCSP). The KNCSP has provided annual faecal immunochemical test (FIT) for adults aged 50 years or older, and colonoscopy or a double-contrast barium enema test to those with positive results from the FIT. High-quality screening colonoscopy is mandatory to achieve maximum possible CRC prevention. The case volume has been shown to correlate with outcomes in surgical specialties. In contrast, relevant data on colonoscopy is limited. This study aimed to assess the quality indicators of organized CRC screening according to annual colonoscopy volume using KNCSP data. Methods: We used the KNCSP data from 2018 to 2020, which accounted for 378,354 colonoscopy examinations. We used cancer registration data of an extended health insurance program using ICD-11 codes (C18-20). A total of 12,109 CRC patients were registered within 1 year of the date of colonoscopy. We calculated the annual number of colonoscopy examinations by an individual endoscopist. We excluded endoscopists who had a very low or high number of examinations with the highest 1% or lowest 1% as outliers. The final number of endoscopists was 16,552 and colonoscopy examinations were 331,231 during 2018–2020. The annual colonoscopy volume by individual endoscopists was divided into four groups (2–12, 13–24, 25–36, and 37 or more examinations). Multiple linear regression analysis was performed to confirm the association between test accuracy indicators and colonoscopy frequency using a generalized linear model (GLM). We calculated the estimates of the rates for each indicator by adjusting the year. Results: The positive and false positive rates, sensitivity, specificity, and positive predictive value were 4.09%, 1.07%, 83.53%, 98.93%, and 74.68%, respectively. The cancer detection and interval cancer rates were 30.53‰ and 6.29‰, respectively. Quality indicators were related to the annual colonoscopy volume of the endoscopist. Endoscopists with a higher annual colonoscopy volume were more likely to have higher sensitivity, specificity, and positive predictive value than those with a lower annual colonoscopy volume. Endoscopists with higher annual colonoscopy volumes were more likely to have lower positive rates, cancer detection rates, false positive rates, and interval cancers rate than those with lower annual colonoscopy volumes. Conclusions: This study found that the annual volume of colonoscopy examinations was associated with better colonoscopy quality in an organized CRC screening program. A high colonoscopy load could be a sign of substantial experience and lead to better outcomes, as has been shown for surgery. The relationship between quality indicators and case volume is logical and plausible; therefore, more research is required to determine the number of cases that need to be performed in a year to adequately maintain high colonoscopy quality.