Sessile Serrated Polyp Detection Research Articles

Sessile serrated polyp detection rates after fecal immunochemical test or multitarget stool DNA test: Systematic review and meta-analysis.

Background and study aims Published studies report a higher adenoma detection rate (ADR) for FIT-DNA as compared with FIT. Data are less replete about the performance of stool-based tests for sessile serrated polyp (SSP) detection. We performed a meta-analysis to evaluate the performance of FIT and FIT-DNA testing for SSP detection rate (SSPDR) in patients undergoing colonoscopy for follow up of positive noninvasive tests. Methods A comprehensive literature search of multiple databases (until September 2022) was performed to identify studies reporting SSPDR in patients with positive FIT or FIT-DNA tests. The outcome was overall colonoscopy detection of any SSPs and advanced serrated polyps (ASP: SSP ≥ 10 mm and/or dysplasia). Results Included were 482,405 patients (52.4% females) with a mean age of 62.3 ± 4.4 years from 23 studies. The pooled SSPDR for all positive stool-based tests was 5.3% and higher for FIT-DNA (15.0%, 95% confidence interval [CI] 8.3-25.7) versus FIT (4.1%, 95% CI 3.0-5.6; P = 0.0002). The overall pooled ASP detection rate was 1.4% (95% CI 0.81-2.3) and higher for FIT-DNA (3.8 %, 95% CI 1.7-8.6) compared with FIT (0.71%, 95% CI 0.36-1.4; P <0.01). SSPDR with FIT-DNA was also significantly higher than FIT when the FIT cutoff was >10 ug/g and in FIT-positive patients in studies conducted in North America ( P <0.05). Conclusions FIT-DNA outperformed FIT in both SSP and ASP detection including FIT with a lower threshold cutoff of >10 ug/g. Further comparative studies are needed to assess the impact of our findings on colorectal cancer reduction.

Propofol sedation does not improve measures of colonoscopy quality but increase cost – findings from a large population-based cohort study

Propofol is often used for sedation during colonoscopy. We assessed the impact of propofol sedation on colonoscopy related quality metrics and cost in a population-based cohort study. All colonoscopies performed at 21 hospitals in the province of Ontario, Canada, during an 18-month period, from April 1, 2017 to October 31, 2018, using either propofol or conscious sedation were evaluated. The primary outcome was adenoma detection rate (ADR) and secondary outcomes were sessile serrated polyp detection rate (ssPDR), polyp detection rate (PDR), cecal intubation rate (CIR), and perforation rate. Binary outcomes were assessed using a modified Poisson regression model adjusted for clustering and potential confounders based on patient, procedure, and physician characteristics. A total of 46,634 colonoscopies were performed, of which 16,408 (35.2%) received propofol and 30,226 (64.8%) received conscious sedation. Compared to conscious sedation, the use of propofol was associated with a lower ADR (24.6% vs. 27.0%, p<0.0001) but not ssPDR (5.0% vs. 4.7%, p=0.26), PDR (40.5% vs 40.4%, p=0.79), CIR (97.1% vs. 96.8%, p=0.15) or perforation rate (0.04% vs. 0.06%, p=0.45). On multi-variable analysis, propofol sedation was not associated with any differences in ADR (RR=0.90, 95% CI 0.74-1.10, p=0.30), ssPDR (RR=1.20, 95% CI 0.90-1.60, p=0.22), PDR (RR=1.00, 95% CI 0.90-1.11, p=0.99), or CIR (RR=1.00, 95% CI 0.80-1.26, p=0.99). The additional cost associated with propofol sedation was $12,730,496 for every 100,000 cases. The use of propofol sedation was not associated with improved colonoscopy related quality metrics but increased costs. The routine use of propofol for colonoscopy should be reevaluated. None.

Colorectal Neoplasia in Asian Americans Undergoing First Time Asymptomatic Average-risk Screening Colonoscopies.

We identified the prevalence and subtype of colorectal neoplasia removed during index screening colonoscopies in a large Asian American population. Asian Americans are the fastest growing demographic group in the United States yet there is a paucity of data on the characteristics of colorectal neoplasia found in this cohort. Cross-sectional study of 2208 index colonoscopies performed on average-risk Asian and White patients at a large, tertiary academic center. Patients were identified via diagnostic or procedure codes between 2015 and 2020, with retrospective classification of polyp histopathology. Univariate and multivariate analysis were performed to identify risk factors associated with colorectal neoplasia. A total of 2208 patients were identified, of which 1085 were Asian. When adjusted for age and sex, Asians were as likely as Whites to have any type of colorectal neoplasia [44.2% vs. 43.5%, odds ratio (OR)=0.93, (CI: 0.78-1.11)]. On multivariate analysis, Asians were less likely to have sessile serrated polyps (5.5% vs. 9.9%, OR=0.53, 95% CI: 0.38-0.73) and more likely to have tubular adenomas in the left colon (22.6% vs. 18.0%, OR=1.33, 95% CI: 1.08-1.64) compared with Whites. Quality measures, such as sessile serrated polyp detection rates, may need to take into account demographic factors such as race. The prevalence of colorectal neoplasia among Asian Americans is substantial and warrants efforts to promote optimal uptake of colorectal cancer screening tests.

Clinicopathological Features of Sessile Serrated Polyps in China: A Retrospective Study of a Tertiary Hospital.

Serrated polyps have been recognized as the important premalignant lesions. In this study, we aimed to analyze the clinicopathological features of sessile serrated polyps and determine the association between sessile serrated polyps and synchronous advanced adenomas. Consecutive patients undergoing diagnostic or therapeutic colonoscopies (including 156 681 diagnostic colonoscopies) from 2011 to 2019 were included. A total of 958 patients, including 699 (73%) males, were detected with at least 1 sessile serrated polyp, and 65.9% (n = 658) of sessile serrated polyps were located in the distal colon. Advanced serrated lesions accounted for 9.1% (n = 91) of all the sessile serrated polyp (n = 999). The types of SSP included flat type (953/999, 95.4%) and sub-pedunculated or pedunculated type (46/999, 4.6%). Meanwhile, there was no obvious evidence supporting the association between advanced adenomas and characteristics of advanced serrated lesions or sessile serrated polyps. Sessile serrated polyps seem to be more frequently seen in the distal colon of men in this study. However, more evidence is required to confirm the actual distribution of sessile serrated polyp in colon among Chinese people. There is still much room for improvement of sessile serrated polyp detection rate, and more importance should be attached to sessile serrated polyp both for pathologists and endoscopists.

Efficacy of oral sulfate tablets for bowel preparation and adenoma detection rate.

The adenoma detection rate (ADR), which is closely related to bowel preparation, is the most important factor for colonoscopy quality assessment. New oral sulfate tablets (OSTs) have been developed to improve bowel preparation compliance. This study evaluated the efficacy of OSTs in terms of the ADR and bowel preparation status. Medical records of subjects under the age of 65 who underwent colonoscopy from March 2019 to February 2021 were retrospectively reviewed. Polyethylene glycol with ascorbic acid (PEG-A) was used as a bowel preparation for the first half of the study period, and OSTs were used for the second half. In total, 16 971 subjects were included in the study: 9199 (54.2%) used PEG-A, and 7772 (45.8%) used OSTs. Bowel cleansing quality was assessed by the Boston Bowel Preparation Scale (BBPS). The average age was 50years. The rate of adequate bowel preparation was higher in the OST group than in the PEG-A group (97.2% vs 95.0%, P<0.001). The mean BBPS was also higher in the OST group (8.02 vs 7.75, P<0.001). The adenomas per colonoscopy (APC), the ADR and the sessile serrated polyp detection rate (SSPDR) were higher in the OST group than in the PEG-A group (APC 0.56±1.01 vs 0.48±0.91, P<0.001; ADR 34.5% vs 30.7%, P<0.001; SSPDR 5.2% vs 3.3%, P<0.001). Compared with PEG-A, OSTs yielded superior APC, ADRs, SSPDRs, and better bowel cleanliness. Therefore, OSTs are a good alternative for patients who have difficulty taking large-volume bowel preparation formulations.

Association of Trainee Participation in Colonoscopy Procedures With Quality Metrics

Trainees routinely participate in colonoscopy procedures, yet whether their involvement is positively or negatively associated with procedural quality is unknown because prior studies involved small number of trainees and/or supervisors, lacked generalizability, and/or failed to adjust for potential confounders. To assess the association between trainee participation and colonoscopy quality metrics. This multicenter population-based cohort study was conducted at 21 academic and community hospitals between April 1, 2017, and October 31, 2018, among consecutive adult patients undergoing colonoscopy. Procedures performed by endoscopists who did not supervise trainees were excluded. Statistical analysis was performed from April 3, 2017, to October 31, 2018. Participation by a trainee, defined as a resident or fellow enrolled in a gastroenterology or general surgery training program. The primary outcome was the adenoma detection rate (ADR), and secondary outcomes were sessile serrated polyp detection rate (ssPDR), polyp detection rate (PDR), cecal intubation rate (CIR), and perforation rate. A total of 35 499 colonoscopies (18 989 women [53.5%]; mean [SD] patient age, 60.0 [14.1] years) were performed by 71 physicians (mean [SD] time in practice, 14.0 [9.3] years); 5941 colonoscopies (16.7%) involved trainees. There were no significant differences in the ADR (26.4% vs 27.3%; P = .19), CIR (96.7% vs 97.2%; P = .07), and perforation rate (0.05% vs 0.06%; P = .82) when trainees participated vs when they did not participate, whereas the the ssPDR (4.4% vs 5.2%; P = .009) and PDR (39.2% vs 42.0%; P < .001) were significantly lower when trainees participated vs when they did not. After adjustment for potential confounders, the ADR (risk ratio [RR], 0.97; 95% CI, 0.91-1.03; P = .30), PDR (RR, 0.98; 95% CI, 0.93-1.04; P = .47), and CIR (RR, 0.93; 95% CI, 0.78-1.10; P = .38) were not associated with trainee participation, although the ssPDR remained significantly lower (RR, 0.79; 95% CI, 0.64-0.98; P = .03). This study suggests that trainee involvement during colonoscopy was associated with reduced ssPDR but not other colonoscopy outcome measures. Extra care should be exercised when examining the right colon when trainees are involved.

Impact of Community Referral on Colonoscopy Quality Metrics in a Veterans Affairs Medical Center.

INTRODUCTION:The Veterans Access, Choice, and Accountability Act of 2014 expands the number of options veterans have to ensure timely access to high-quality care. There are minimal data currently available analyzing the impact and quality of colonoscopy metrics in veterans receiving procedures within the Department of Veterans' Affairs (VA) vs community settings.METHODS:All patients at our academic VA medical center who were referred to a community care colonoscopy (CCC) for positive fecal immunochemical testing, colorectal cancer screening, and adenoma surveillance from 2015 to 2018 were identified and matched for sex, age, and year of procedure to patients referred for a VA-based colonoscopy (VAC). Metrics measured included time to procedure measured in days, adenoma detection rate (ADR), advanced ADR (AADR), adenomas per colonoscopy, sessile serrated polyp detection rate, cecal intubation rate, bowel preparation quality, and compliance with guideline recommendations for surveillance. Patient comorbidities were also recorded. Variable associations with adenoma detection and compliance with surveillance guidelines were analyzed with univariate and multivariate logistic regression.RESULTS:In total, 235 veterans (mean age, 64.6 years, and 95.7% male) underwent a CCC and had an appropriately matched VAC. ADR in the community was 36.9% compared with 62.6% for the VAC group (P < 0.0001). The mean number of adenomas per procedure in the community was 0.77 compared with 1.83 per VAC (P < 0.0001). CCC AADR was 8.9% compared with 18.3% for VAC (P = 0.003). The cecal intubation rate for community colonoscopies was 90.6% compared with 95.3% for VA colonoscopies (P = 0.047). Community care compliance with surveillance guidelines was 74.9% compared with 93.3% for VA (P < 0.0001). This nonconformity was primarily due to recommending a shorter interval follow-up in the CCC group (15.3%) compared with the VAC group (5.5%) (P = 0.0012). The mean time to procedure was 58.4 days (±33.7) for CCC compared with 83.8 days (±38.6) for VAC (P < 0.0001). In multivariate regression, CCC was associated with lower ADR (odds ratio 0.39; 95% confidence interval, 0.20–0.63) and lower compliance with surveillance guidelines (odds ratio 0.21; 95% confidence interval, 0.09–0.45) (P < 0.0001 for both).DISCUSSION:Time to colonoscopy was significantly shorter for CCC compared with VAC. However, compared with VA colonoscopies, there was significantly lower ADR, AADR, and surveillance guideline compliance for services rendered by community providers. This impact on quality of care should be further studied to ensure that colonoscopy quality standards for veterans are not compromised by the process of care and site of care.

Impact of the Sessile Serrated Polyp Pathway on Predicted Colorectal Cancer Outcomes

<h3>Background and Aims</h3> Approximately 20%–30% of colorectal cancers (CRCs) arise from the serrated polyp pathway. CRC screening options have differential sensitivity to detect sessile serrated polyps (SSPs). We used the Colorectal Cancer and Adenoma Incidence and Mortality Microsimulation Model (CRC-AIM) to assess how the detection of SSPs impacts predicted life years gained (LYG), CRC incidence, and CRC mortality with multitarget stool DNA (mt-sDNA) or fecal immunochemical test (FIT) screening. <h3>Methods</h3> A simulated cohort of average-risk US individuals underwent triennial mt-sDNA or annual FIT screening between ages 45–75 years. SSP-attributed CRCs were modeled at 0% (base case), 14.3%, 20%, and 30%, in combination with 4 adherence & attendance scenarios: S1: 100% stool-screening adherence/100% follow-up colonoscopy attendance after a positive stool test; S2: reported stool-screening adherence (mt-sDNA = 71%; FIT = 43%)/100% follow-up colonoscopy attendance; S3: reported stool-screening adherence/reported follow-up colonoscopy attendance (mt-sDNA = 72%; FIT = 47%); and S4: reported stool-screening adherence/72% follow-up colonoscopy attendance. Outcomes were per 1000 individuals. Sensitivity analyses used ranges of stool-screening adherence or follow-up attendance. <h3>Results</h3> At S1, S2, S3, and S4, LYG with FIT at the base case (0% SSP-attributed CRC) was 346.7, 279.3, 126.6, and 196.1, respectively, and with mt-sDNA was 324.6, 311.8, 215.8, and 215.8, respectively. Among the 4 adherence/attendance scenarios, modeling SSP-attributed CRCs decreased LYG by 4.9–20.9 with FIT and 2.0–5.1 with mt-sDNA. At S3 and 30% SSP-attributable CRCs, mt-sDNA had 95.1 more LYG, 21.5% greater CRC incidence reduction, and 22.2% greater CRC mortality reduction than FIT. <h3>Conclusion</h3> Incorporating SSPs and real-world adherence into the CRC-AIM modeling analyses yielded more practice-relevant estimates of CRC screening outcomes and should be applied in future studies to afford more appropriate assessment of comparative effectiveness estimates between guideline-endorsed screening options.

Almost One-Third of Large Sessile Serrated Polyps Are Missed on CT Colonography.

Nearly one-third of colorectal cancers (CRC) arise via the serrated pathway. CT colonography (CTC) is a CRC screening examination. Endoscopic detection of sessile serrated polyps (SSPs) varies widely; it is unknown whether CTC effectively detects SSPs. The aim of this study is to determine whether CTC detects SSPs at an institution that performs a large volume of CTC. We conducted a search of pathology records to identify serrated polyps (SPs) from 2005 to 2012. We extracted demographic data from the electronic health records (EHRs) of subjects with an SSP and examined endoscopy reports for location and size of each SSP. We identified subjects with a CTC within 1 year prior to the colonoscopy that found an SSP, and determined if the CTC identified the SSP. Our search found 3978 subjects with SP over the 7-year period. Seven hundred thirty-two subjects had at least 1 SSP. Eightytwo subjects had CTC done within 1 year prior to the colonoscopy that identified SSP. Seventy-nine subjects' polyps were identified on CTC. CT colonography was done an average of 38 ± 54 days prior to colonoscopy. One hundred fifteen SSPs were identified endoscopically. A total of 48.7% of all SSPs were identified via CTC; larger SSPs were more likely to be seen on CTC (P < .001), and 69.6% of SSPs larger than 10 mm were found via CTC. Proximal SSPs were more often identified than distal SSPs (P = .005). Given the miss rate for SSPs on CTC, endoscopists should be vigilant about examining the proximal colon in subjects referred after CTC, even if the imaging does not reveal a proximal polyp.

S335 Sessile Serrated Polyps - More Prevalent Than Previously Thought

Introduction: Sessile serrated polyps (SSP) are precursors of up to 30% of colorectal cancers. There are significant differences in the documented prevalence of SSPs in the literature, ranging from 3-10%. We aimed to clarify the prevalence of SSPs by gender, ethnicity, age, and obesity in a large academic medical center in Southern California. Methods: Data was analyzed retrospectively, including all screening and surveillance colonoscopies performed at our tertiary outpatient facility from 2012 to 2019. We evaluated gastroenterologists who performed at least 200 colonoscopies and included all patients over the age of 40. Statistical analysis was performed using chi-square and two-sample t-test. Results: Among 4,430 colonoscopies evaluated, 2,269 (51.2%) were in females. 495 of the procedures had at least one SSPs detected (11.2%). whites had higher SSP detection rates (SDR) compared to non-white ethnicities (13% vs 8%, p< 0.01). There were no differences in SDR based on gender (P=0.10), advanced age >70 (P=0.65) or obesity (P=0.54). Compared with adenomas, SSPs were generally larger with an average size of 7.4mm compared to 4.1mm (p< 0.01) and had a higher percentage of polyps >9mm (21.8% vs 7.2%, p< 0.01). SSPs were also more likely to be found in the proximal colon compared to adenomas (75.9% vs 63.8%, p< 0.01). Conclusion: Our study shows a higher prevalence of SSPs detected during colonoscopy than previously established, especially in whites. Our data confirms previous studies which showed that SSPs tend to be right sided and larger than adenomas. However, this size difference may reflect a larger miss rate for small SSPs, which tend to be flat and difficult to find. While SSPs are not as commonly detected as adenomas, they play a significant role in the development of colorectal cancer, especially interval cancers. As such, endoscopists should be rigorous in their evaluation to recognize all sessile serrated lesions.

S243 Gastroenterologist Focus of Clinical Practice Affects Adenoma Detection in Screening Colonoscopy

Introduction: Screening colonoscopy stands as the gold standard of preventative care for colorectal cancer. The procedure is done by endoscopists with varying degrees of training. As the percentage of screening colonoscopies increases among the nations, improving the quality of procedures would have significant impact on plausible outcomes. Our objective was to determine whether the clinical focus of practice would affect screening colonoscopy quality metrics, specifically adenoma detection. Methods: We conducted a retrospective study of screening colonoscopies performed at an academic ambulatory surgical center. We categorized the gastroenterologists based on their clinical subspecialty focus, which includes general/motility, hepatology, inflammatory bowel disease (IBD), and interventional endoscopy. We looked at variables pertaining to the patients’ and providers’ backgrounds and the procedural reports. The primary outcome was adenoma detection (AD) with secondary outcome of adenoma and/or sessile serrated polyp detection (AD+SSP). Multivariable logistic regression analysis was applied. Results: A total of 5,271 (male: 49.1%) complete first-time screening colonoscopies were performed from 2010 to 2020 by 16 gastroenterologists (male: 62.5%, general/motility specialists: 3, hepatologists: 3, IBD specialists: 4, interventional endoscopists: 6). 87.6% had either adequate, good, or excellent bowel preparation. The AD rate between each specialty focus were 27.5% (n = 264) for general/motility, 31.4% (n = 409) for hepatology, 38.4% (n = 346) for IBD, and 37.5% (n = 765) for interventional endoscopy. The AD+SSPs rate between each specialty focus were 31.0% (n = 298) for general/motility, 35.5% (n = 467) for hepatology, 43.6% (n = 396) for IBD, and 43.2% (n = 889) for interventional endoscopy. Binary regression analysis was performed with AD and AD+SSP as the outcome of interest, and the results are shown in Table 1. Male gender followed by subspecialty focus of practice, and withdrawal time were independent factors in finding adenomatous polyps. Acceptable bowel preparation enhanced AD+SSP detection in addition to aforementioned factors, Table 1. Conclusion: Gastroenterologists met all key quality metrics for screening colonoscopies. However, subspecialty focus of practice is important factor in adenoma detection rate along with patient’s male gender, bowel preparation, and withdrawal time. The result of this study may need further validation with larger multicenter prospective studies.Table 1.: Regression analysis finding independent factors for detecting polyps

S291 Sessile Serrated Polyp Detection Rate of 2% or Greater Is Associated With a Lower Risk for Post-Colonoscopy Colorectal Cancer

S291 Sessile Serrated Polyp Detection Rate of 2% or Greater Is Associated With a Lower Risk for Post-Colonoscopy Colorectal Cancer

Rectal Evacuation Disorders are Associated With Poor Bowel Preparation in Patients With Chronic Constipation: Results From Two Centers.

We evaluated factors that can predict the adequacy of bowel preparation in patients with chronic constipation undergoing colonoscopy. We identified patients with chronic constipation who underwent anorectal manometry and at least 1 colonoscopy at 2 tertiary referral centers from 2003 to 2019. We also identified a subgroup of patients who underwent colonic transit testing through radiopaque marker testing. We determined demographic, medical, and constipation-related factors associated with poor bowel preparation and their effect on standardized quality metrics using univariate and multivariate analyses. We identified 274 patients with chronic constipation who underwent anorectal manometry testing. Both outlet dysfunction (prolonged balloon expulsion) and slow-transit constipation were associated with suboptimal bowel preparation. Outlet dysfunction was also associated with decreased cecal intubation rates, adenoma detection rates, and sessile serrated polyp detection rates. In multivariable analyses controlling for demographics and known factors associated with poor bowel preparation, outlet dysfunction was associated with an almost 3-fold odds of suboptimal bowel preparation [odds ratio (OR): 2.9; 95% confidence interval (CI): 1.6-5.1] and a 3-fold reduction in cecal intubation rates (OR: 0.3; 95% CI: 0.1-0.8). Among those with radiopaque marker colonic transit testing available, slow-transit constipation was associated with a >2-fold odds of suboptimal bowel preparation (OR: 2.2; 95% CI: 1.1-4.4). Among a cohort of patients with chronic constipation undergoing colonoscopy, outlet dysfunction was associated with suboptimal bowel preparation and other quality metrics. Constipated patients with a rectal evacuation disorder may represent a subgroup of patients that could benefit from individualized strategies for better bowel preparation.

Sessile serrated adenomas detection rate among the surgeons and the gastroenterologists: A retrospective analysis

Background: Sessile serrated adenomas (SSAs) are flat or sessile benign lesions occasionally covered by a mucous cap and invariably lead to colorectal cancer. The adenoma detection rate (ADR) is recognized as an important quality measure for colonoscopy. Objective: The objective of the study was to evaluate and compare the ADR during colonoscopy among surgeons and gastroenterologists. Materials and Methods: In this retrospective analysis, all colonoscopies performed during July 2018–July 2019 at Caboolture Hospital, Queensland, Australia were included in the study. After considering the inclusion and exclusion criteria, the rate of sessile polyp detection among the gastroenterologist versus surgeons was investigated by calculating a correlation coefficient weighted by factors such as experience, colonoscopy intubation time, and removal of scopes. Results: A total of 3425 colonoscopies performed by 7 surgeons and 4 gastroenterologists were assessed. Among them, 58.7% colonoscopies were performed by the surgeons, while gastroenterologists performed 41.3% colonoscopies. The median age of patients was 56.5 years (25–88 years), more common in male than female (58.9% and 41.1%, respectively, p<0.0001). The average withdrawal time among the surgeons and gastroenterologist was 8.05 and 8.54 min, respectively (p=0.02). Mean cecal intubation rate among the surgeons and gastroenterologist was 94.7% and 97.4%, respectively. Most patients had adequate bowel preparations; however, poor bowel preparation was observed among 6.15% gastroenterology patients and 5.6% in surgical patients. Conclusion: Based on the longer withdrawal time and improved skillset, sessile serrated polyp detection rate during colonoscopy was higher among the gastroenterologist as compared to the surgeons.

Serrated Lesion Detection in a Population-based Colon Screening Program.

Serrated lesions give rise to 15% to 30% of all colorectal cancers, driven predominantly by the sessile serrated polyp (SSP). Fecal immunochemical test (FIT), has low sensitivity for SSPs. SSP detection rate (SSPDR) is influenced by performance of both endoscopists and pathologists, as diagnosis can be subtle both on endoscopy and histology. To evaluate the SSPDR in a population-based screening program, and the influence of subspecialty trained pathologists on provincial reporting practices. The colon screening program database was used to identify all FIT-positive patients that received colonoscopy between January 2014 and June 2017. Patient demographics, colonoscopy quality indicators, pathologic diagnoses, and FIT values were collected. This study received IRB approval. A total of 74,605 colonoscopies were included and 26.6% had at least 1 serrated polyp removed. The SSPDR was 7.0%, with 59% of the SSPs detected having a concurrent conventional adenoma. The mean FIT value for colonoscopies with only serrated lesions was less than that for colonoscopies with a conventional adenoma or colorectal cancer (P<0.0001). Centers with a gastrointestinal subspecialty pathologist diagnosed proportionally more SSPs (P<0.0001), and right-sided SSPs than centers without subspecialists. Serrated lesions often occur in conjunction with conventional adenomas and are associated with lower FIT values. Knowledge of the characteristics of SSPs is essential for pathologists to ensure accurate diagnosis of SSPs.

A117 PROPOFOL SEDATION DOES NOT IMPROVE MEASURES OF COLONOSCOPY QUALITY – FINDINGS FROM THE SOUTHWEST ONTARIO COLONOSCOPY COHORT

Abstract Background The use of propofol during colonoscopy has gained increased popularity due to deeper anesthesia compared to conscious sedation. Prior studies examining the use of propofol sedation during colonoscopy have primarily focused on anesthesia outcomes. Whether propofol sedation is associated with improvements in colonoscopy outcomes is uncertain. Aims The primary outcome was adenoma detection rate (ADR). Secondary outcomes were the detection of any adenoma (conventional adenoma, sessile serrated polyp, and traditional serrated adenoma), sessile serrated polyp detection rate, polyp detection rate, cecal intubation rate, and perforation rate. Methods The Southwest Ontario Colonoscopy cohort consists of all patients who underwent colonoscopy between April 2017 and Oct 2018 at 21 hospitals serving a large geographic area in Southwest Ontario. Procedures performed in patients less than 18 years of age or by endoscopist who perform &amp;lt;50 colonoscopies/year were excluded. Data were collected through a mandatory quality assurance form that was completed by the endoscopist after each procedure. Pathology reports were manually reviewed. Results A total of 46,634 colonoscopies were performed by 75 physicians (37.5% by gastroenterologists, 60% by general surgeons, 2.5% others) of which 16,408 (35.2%) received propofol and 30,226 (64.8%) received conscious sedation (e.g. combination of a benzodiazepine and a narcotic). Patients who received propofol were likely to have a screening indication (49.2% vs 45.5%, p&amp;lt;0.0001), not have a trainee endoscopist present and be performed at a non-academic centre (32.2% vs 44.6%, p&amp;lt;0.0001). Compared to conscious sedation, use of propofol was associated with a lower ADR (24.6% vs. 27.0%, p&amp;lt;0.0001) and detection of any adenoma (27.7% vs. 29.8%, p&amp;lt;0.0001); no difference was observed in the detection ofsessile serrated polyps (5.0% vs. 4.7%, p=0.26), polyp detection rate (41.2% vs 41.2%, p=0.978), cecal intubation rate (97.1% vs. 96.8%, p=0.15) or perforation rate (0.04% vs. 0.06%,p=0.45). On multi-variable analysis, the use of propofol was not significantly associated with any improvement in ADR (RR=0.90, 95% CI 0.74–1.10, p=0.30), detection of any adenoma (RR=0.93, 95% CI 0.75–1.14, p=0.47), sessile serrated polyp detection rate (RR=1.20, 95%CI 0.90–1.60, p=0.22), polyp detection rate (RR=1.00, 95% CI 0.90–1.11, p=0.99), or cecal intubation rate (RR=1.00, 95%CI 0.80–1.26, p=0.99). Conclusions The use of propofol sedation does not improve colonoscopy quality metrics. Funding Agencies None

A134 A MULTI-CENTRE RANDOMIZED CONTROLLED TRIAL TO COMPARE TWO BOWEL CLEANSING REGIMENS AFTER A COLONOSCOPY WITH INADEQUATE BOWEL PREPARATION

Abstract Aims Failed bowel preparation is common during colonoscopy, yet the optimal purgative regimen to use for the next attempt is unknown. The objective of this study was to compare the efficacy, tolerability, and safety of two regimens at supratherapeutic doses for use after failed bowel preparation. Methods A multi-centre phase III endoscopist blinded randomized controlled trial (NCT02976805) was conducted in patients who failed bowel preparation, using the US Multi-Society Task Force (USMSTF) definition of inability to exclude polyps &amp;gt;5 mm in size and requiring a shortened interval to next colonoscopy. Regimen A consisted of 15 mg of bisacodyl and 2 + 2 L of split dose polyethylene glycol electrolyte solution (PEG) and Regimen B consisted of 15 mg of bisacodyl and 4 + 2 L of split dose PEG. The primary outcome was adequate bowel preparation, defined as a Boston Bowel Preparation Scale (BBPS) total score ≥ 6 with all segment scores ≥ 2. Secondary outcomes were adequate bowel preparation using the USMSTF definition, median BBPS, adenoma detection (ADR), advanced adenoma detection (aADR), sessile serrated polyp detection (SSPDR), and cecal intubation (CIR). Adverse events were assessed at the time of the colonoscopy and 14 days later. Results Between February 2017 and December 2019, 250 subjects were screened at four academic centres in Canada, of which 195 were randomized: 96 to Regimen A and 99 to Regimen B. The mean (SD) age was 60.6 (11.4) years, 87 (45.1%) were female, and the median (IQR) total BBPS score at previous failed colonoscopy was 3 (1,4). Regimen B was not superior to Regimen A in achieving adequate bowel preparation using the BBPS definition (87.6% vs. 91.1%, p=0.45) or the USMSTF definition (85.4% vs 91.1%, p=0.24), nor was it superior with respect to the median BBPS score (7 vs 7, p=0.50), mean ADR (31.5% vs 37.8%, p=0.37), aADR (11.2% vs 18.9%, p=0.15), SSPDR (5.6% vs 8.9%, p=0.40) or CIR (92.1% vs 96.7%, p=0.19). Regimen A had a higher adherence rate (88.2% vs. 74.7%, p=0.02) and greater willingness to undergo the bowel preparation again (91.2% vs. 66.2%, p&amp;lt;0.001). The only serious adverse event occurred in a patient randomized to Regimen B who was admitted to hospital for vomiting after colonoscopy. Conclusions Split dose 4L PEG with 15mg of bisacodyl is highly efficacious, well tolerated, and can be used for patients who previously failed first line bowel preparations. The additional 2L of PEG in Regimen B did not improve bowel preparation and was not as well tolerated. Funding Agencies AMOSO Opportunities Grant, Pharmascence Inc.

A108 ARE INPATIENTS STILL MORE LIKELY TO FAIL BOWEL PREPARATION IN THE SPLIT-DOSE ERA? FINDINGS FROM 47, 292 COLONOSCOPIES IN THE SOUTHWEST ONTARIO COLONOSCOPY COHORT

Abstract Background Prior studies before the widespread use of split-dose bowel preparation have shown a high rate of inadequate bowel preparation in hospitalized patients. Whether this is still true in the era of split-dose bowel preparation is unknown. Aims To determine the impact of inpatient status on bowel preparation quality in the contemporary era of split-dose bowel preparation. Methods The Southwest Ontario Colonoscopy cohort consists of all inpatient and outpatient colonoscopies performed between April 2017 and Oct 2018 at 21 hospitals serving a large geographic health region. Procedures done in patients &amp;lt; 18 years of age or by an endoscopist performing &amp;lt;50 colonoscopies/year were excluded. Data were collected through a mandatory quality assurance form that was completed by the endoscopist after each procedure. Pathology reports were manually reviewed. The primary outcome was adequate bowel preparation, defined on an ordinal scale as “good” or “fair” rather than “poor”. Secondary outcomes included adenoma detection rate (ADR), sessile serrated polyp detection rate (ssPDR), polyp detection rate (PDR), and cecal intubation rate (CIR). Results A total of 47,292 colonoscopies were performed by 75 physicians (36.2% by gastroenterologists, 60% by general surgeons, 4% others), of which 1,690 were inpatients (3.6%). Inpatients were older (mean 66.8 years vs 60.2 years, p&amp;lt;0.0001), more co-morbid (≥ASA grade 3, 53.6% vs 23.7%, p&amp;lt;0.0001), performed for symptomatic indications (95.7% vs 48.6%, p&amp;lt; 0.0001), have trainee involvement (47% vs 11.6% p&amp;lt;0.001), and less likely to receive split-dose bowel preparation (71.7% vs 91.6% p&amp;lt;0.001). On crude analysis, inpatients were less likely to have adequate bowel preparation (86.2% vs 97.6% p&amp;lt;0.001). On multi-variable analysis, inpatients had lower odds of achieving adequate bowel preparation (OR=0.41, 95% CI 0.33 - 0.50, p&amp;lt;0.001), lower ADR (OR=0.47, 95% CI 0.40 - 0.55, p&amp;lt;0.001), lower PDR (OR=0.54, 95% CI 0.47 - 0.61 p&amp;lt;0.001) and lower CIR (OR = 0.43, 95% CI 0.35 - 0.54, p&amp;lt;0.001). Conclusions In the era of split-dose bowel preparation, inpatient status is still an important predictor of inadequate bowel preparation with resultant lower quality outcome metrics. Funding Agencies None

A120 NO EVIDENCE OF A FRIDAY EFFECT ON COLONOSCOPY QUALITY OUTCOMES

Abstract Background Colonoscopy quality may be influenced by operator fatigue. Prior studies have shown lower adenoma detection rates for procedures performed at the end of the day. However, it is unknown if colonoscopy quality is impaired at the end of the work week. Aims We investigated whether colonoscopy quality-related metrics differ at the end of the work week using the South West Ontario Colonoscopy Cohort. Methods Between April 2017 to February 2018, 45,510 consecutive colonoscopies from 20 academic and community hospitals in our health region were captured to form the cohort. In Canada, outpatient endoscopies are generally performed between Monday to Friday, taking Friday, or the last business day, as the last day of the work week compared to the rest of the work week. When a statutory holiday occurred on a Friday, Thursday was designated the last day of the work week. The primary outcome was adenoma detection rate (ADR), and secondary outcomes were sessile serrated polyp detection rate (ssPDR), polyp detection rate (PDR), and failed cecal intubation. Outcomes were presented as unadjusted and adjusted risk ratios derived from modified Poisson regression and adjusting for physician-level clustering, and characteristics of the patient (age, sex, severity), procedure (hospital setting, trainee presence, indication, sedation, bowel preparation quality) and physician (experience and specialty). Results During the observation period, 9,132 colonoscopies were performed on the last day of the work week compared to 36,378 procedures during the rest of the work week. No significant difference was observed for ADR (26.4% vs. 26.6%, p=0.75), ssPDR (4.5% vs. 5.0%, p=0.12), PDR (44.1% vs. 43.1%, p=0.081), or failed cecal intubation (2.8% vs. 2.9%, p=0.51) for colonoscopies performed on the last day of the work week compared to the rest of the week, respectively. After adjusting for potential confounders, there were no significant differences in the ADR (RR 1.01, 95% CI [0.88, 1.15], p=0.94), ssPDR (RR 0.90, 95% CI [0.70, 1.14], p=0.38), PDR (RR 1.00, 95% CI [0.92, 1.09], p=0.94), or failed cecal intubation (RR 0.92, 95% CI [0.72, 1.18], p=0.51) for colonoscopies performed on the last day of the work week compared to the rest of week, respectively. Conclusions Colonoscopy quality metrics, including ADR, ssPDR, PDR, and failed cecal intubation are not significantly different at the end of the week. Funding Agencies None

A113 ANNUAL COLONOSCOPY VOLUME IS NOT PREDICTIVE OF COLONOSCOPY QUALITY - FINDINGS FROM THE SOUTHWEST ONTARIO COLONOSCOPY COHORT

Abstract Background Performing a minimum number of colonoscopies annually has been proposed by some jurisdictions as a requirement for maintaining privileges. However, this practice is supported by limited evidence. Aims The objective of this study was to determine if annual colonoscopy volume was associated with colonoscopy quality metrics. Methods A population-based study was performed using the Southwest Ontario Colonoscopy cohort, which consists of all adult patients who underwent colonoscopy between April 2017 and Oct 2018 at 21 academic and community hospitals within the health region. Data were collected through a mandatory quality assurance form completed after each procedure and pathology reports were manually reviewed. Physician annualized colonoscopy volumes were compared by correlation analysis to each quality-related outcome, by means of the area under the receiver operating characteristics curve (AUROC), and logistic regression. The prognostic value of colonoscopy volume was also adjusted for case-mix and potential confounders in separate regression analyses for each outcome. The primary outcome was ADR. Secondary outcomes were polyp detection rate (PDR), sessile serrated polyp detection rate (SSPDR), and cecal intubation. Results A total of 47,195 colonoscopies were performed by 75 physicians (37.5% by gastroenterologists, 60% by general surgeons, 2.5% others). There were no clear relationships between annual colonoscopy volumes and study outcomes. Colonoscopy volume was not associated with ADR (OR 1.03, 95% CI 0.96–1.10, p=0.48) and corresponded to an AUROC not significantly different from the null (AUROC 0.52, 95% CI 0.43–0.61, p=0.65). Multi-variable regression adjusting for case-mix also demonstrated no predictive value of annual colonoscopy volume for the primary outcome (OR 1.03, 95% CI 0.94–1.12, p=0.55). Similarly, analyses of secondary outcomes failed to find an association between colonoscopy volume and PDR, SSPDR, or cecal intubation (Table 1). Conclusions Annual colonoscopy volumes do not predict ADR, PDR, SSPDR, or cecal intubation rate. Results of unconditional and conditional approaches for examining the predictive value of annual colonoscopy volume for quality related outcomes. Funding Agencies None