Colorectal cancer (CRC) is a significant public health problem, as its incidence has been increasing worldwide [1,2]. As most CRC develops from colorectal adenoma through the adenoma-carcinoma sequence, CRC screening has decreased CRC incidence and mortality through early detection and removal of colorectal adenoma [3,4]. Several Western countries such as Australia, Germany, Poland, Switzerland, and the United States use colonoscopy as primary CRC screening [5]. Recently, the adoption of colonoscopy as a primary CRC screening tool has been argued in Korea.

In Western countries, limited resources for colonoscopy have been an obstacle in expanding CRC screening program [6-8]. Until now, little is known for the the present and potential colonoscopic capacity, colonoscopic quality, and adherence to colonoscopy surveillance guideline recommendations in Korea. A better understanding of these information may be the first step towards successful implementation of primary colonoscopy screening as well as identification of deficits in the current colonoscopic resources in Korea. Considering excellent accessibility of colonoscopy, low cost of colonoscopy, and the availability of experienced colonoscopists in Korea, the current Korea’s data may be different from those of Western countries.

In this context, we evaluated the present and potential colonoscopic capacity, colonoscopic quality, and adherence to colonoscopy surveillance guideline recommendations in Korea.

We sent a web link e-mail to 72 representative physicians in hospitals nationwide, and 62 of them answered with a response rate of 86%. Overall, survey results from 51 of the total 62 respondents were analyzed after exclusion of 11 surveys with incomplete answers. The complete overall response rate was 71.0%.

This is the first study evaluating the colonoscopic capacity, colonoscopic quality, and adherence to colonoscopy surveillance guideline recommendations in Korea. For the potential colonoscopic capacity, only 1 of 3 of endoscopy units can afford to perform additional colonoscopies, and only 8 cases of colonoscopies per working day might be performed in addition to the current practice. Despite recent issues of qualified colonoscopy in Korea, monitoring and reporting of quality indicators of colonoscopy were suboptimal and considerably variable (29.4%-94.1%) between endoscopy units. Furthermore, there are substantial gaps in the adherence to guideline recommendations for surveillance colonoscopy as concordance rate for guideline recommendation was less than 50% in most scenarios.

During sedative colonoscopy in Korea, a benzodiazepine is most commonly used under monitoring by the staffs who were working in each examination room. Our finding was contrasted those of European studies [13-15], in which profofol were preferred to benzodiazepines. The major concerns regarding the risks of adverse events [16] with propofol use may prohibit its widespread use in Korea. Characteristics of sedation and monitoring during colonoscopy may be influenced by the safety concerns of patients and colonoscopists, reimbursement policies, and the variable health care systems of each country; therefore, further studies to optimize sedation and monitoring for colonoscopy are warranted in each country.

For the potential colonoscopic capacity, we assumed that many endoscopy units can afford to more colonoscopies in addition to current practice. It was surprising that only 1 of 3 of endoscopy units can afford to perform additional colonoscopies in addition to the current practice. Our survey results suggest that the potential colonoscopic capacity may not be able to adequately respond to the increasing demand of colonoscopy in Korea. Even though our survey results are subject to bias associated with self-reported data, it may suggest areas for further investigation as the colonoscopic capacity appropriate to meet the increasing demand of colonoscopy screening in Korea has not been fully established. In the United States, colonoscopic capacity limitation have been an obstacle in expanding colonoscopic procedures [17]. In the U.S. survey [18], only 63% of the volume of colonoscopies could be performed with their available resources in 2002. Considering only certain specialists are trained to perform colonoscopy and all positive CRC screening tests are typically followed by a colonoscopy, issues of colonoscopic capacity must be underlined in Korea.

To provide adequate colonoscopy screening, the issue of quality must be addressed. In our study, monitoring and reporting of quality indicators of colonoscopy were suboptimal and considerably variable between endoscopy units. In the United States and Europe, rates of reporting of colonoscopy quality indicators were likewise variable and suboptimal, either [19,20]. These common findings demonstrate the need for regular and efficient assessment of colonoscopic quality in clinical practice. In our survey, the most frequently monitored indicators are cecal intubation rate, followed by withdrawal time more than 6 minutes, procedure-related complications, bowel preparation, PDR/ADR, and patient satisfaction. Provider-oriented indicators, such as cecal intubation rate or withdrawal time, were relatively well monitored. However, patient-oriented indicators, such as patient satisfaction, was insufficiently monitored. Therefore, implementation of quality reporting in colonoscopy, especially for patient-oriented indicators, should be emphasized.

Our survey results show that there are substantial gaps in the adherence to guideline recommendations for surveillance colonoscopy in Korea, which was consistent with previous studies [21,22]. In our survey, most of the respondents favored shorter surveillance intervals than guideline recommendations in most scenarios, though overuse of surveillance colonoscopy leads to unnecessary costs and risks associated with unnecessary colonoscopy [23]. Over-recommendation of surveillance colonoscopy may be due to their concern about interval CRCs [24,25], lower colonoscopy costs, or lack of confidence in the guidelines [9,26,27]. In our study, the adherence rate was less for sessile serrated polyps, which were recently included in guideline recommendations. Therefore, efforts to increase the colonoscopist’s awareness and knowledge about the guidelines may be necessary. Because the potential barriers to guideline adherence were physician awareness, familiarity, and agreement [28], only 54.9% of familiarity for the guidelines and 68.6% of agreement rate with the guidelines should be improved for optimal guideline adherence. Although 62.7% of respondents thought that a guideline is a convenient source of advice, they had difficulty to keep that guidelines in their clinical practice because of many reasons, including a legal issue.

Our study has several strengths. First, we surveyed the nationwide endoscopy units and the overall response rate was high as 86%. Our high response rate was possible because representative physicians were all members of KASID, and contact information was provided by KASID. Furthermore, survey responses were monitored, and follow-up e-mails were sent weekly to non-participating respondents. Second, our survey results represent the current state of colonoscopies in Korea because respondents were the representative physicians of endoscopy units nationwide. Finally, the questionnaire was developed by academic and community gastroenterologists, and covered the topics of colonoscopic capacity, colonoscopic quality, and guideline adherence. Our study results also need to be interpreted in the context of potential limitations. First, the generalization of this study may be limited due to selection bias because survey respondents were highly experienced gastroenterologists working at hospitals. In addition, the respondents’ answers may differ from that of non-respondents. Second, there may be a selection bias as all study respondents were gastroenterologists, however, they surveyed as a representative physician of endoscopy units, including non-gastroenterologists who perform colonoscopy. A larger survey including non-gastroenterologists and variable endoscopy settings may be warranted to overcome these limitations. Third, similar to most survey studies, this survey relied wholly on the knowledge and the answer of the respondents. Fourth, the definition of colonoscopic capacity is relatively subjective and may be compromised with the waiting time, however, we failed to find any objective definition. Finally, the respondents’ size was small. However, our respondents were representative physicians and were not selected by random methods. Therefore, our findings could be interpreted as nationwide Korean data, despite a small sample size.

In conclusion, the potential capacity and quality of colonoscopy in Korea was suboptimal. Considering suboptimal reporting of colonoscopic quality indicators and low adherence rate for colonoscopy surveillance guidelines, quality improvement of colonoscopy and a better adherence of colonoscopy surveillance guideline should be underlined in Korea.