Association between improved adenoma detection rates and interval colorectal cancer rates after a quality improvement program

Establishment and validation of an artificial intelligence-based model for real-time detection and classification of colorectal adenoma

Colorectal cancer (CRC) prevention requires early detection and removal of adenomas. We aimed to develop a computational model for real-time detection and classification of colorectal adenoma. Computationally constrained background based on real-time detection, we propose an improved adaptive lightweight ensemble model for real-time detection and classification of adenomas and other polyps. Firstly, we devised an adaptive lightweight network modification and effective training strategy to diminish the computational requirements for real-time detection. Secondly, by integrating the adaptive lightweight YOLOv4 with the single shot multibox detector network, we established the adaptive small object detection ensemble (ASODE) model, which enhances the precision of detecting target polyps without significantly increasing the model's memory footprint. We conducted simulated training using clinical colonoscopy images and videos to validate the method's performance, extracting features from 1148 polyps and employing a confidence threshold of 0.5 to filter out low-confidence sample predictions. Finally, compared to state-of-the-art models, our ASODE model demonstrated superior performance. In the test set, the sensitivity of images and videos reached 87.96% and 92.31%, respectively. Additionally, the ASODE model achieved an accuracy of 92.70% for adenoma detection with a false positive rate of 8.18%. Training results indicate the effectiveness of our method in classifying small polyps. Our model exhibits remarkable performance in real-time detection of colorectal adenomas, serving as a reliable tool for assisting endoscopists.

Endoscopist adenomas-per-colonoscopy detection rates and risk for postcolonoscopy colorectal cancer: data from the New Hampshire Colonoscopy Registry

BACKGROUND AND AIMS

Adenomas per colonoscopy (APC) may be a better measure of colonoscopy quality than adenoma detection rate (ADR) because it credits endoscopists for each detected adenoma. There are few data examining the association between APC and postcolonoscopy colorectal cancer (PCCRC) incidence. We used data from the New Hampshire Colonoscopy Registry to examine APC and PCCRC risk.

METHODS

We included New Hampshire Colonoscopy Registry patients with an index examination and at least 1 follow-up event, either a colonoscopy or a colorectal cancer (CRC) diagnosis. Our outcome was PCCRC defined as any CRC diagnosed ≥6 months after an index examination. The exposure variable was endoscopist-specific APC quintiles of .25, .40, .50, and .70. Cox regression was used to model the hazard of PCCRC on APC, controlled for age, sex, year of index examination, index findings, bowel preparation, and having more than 1 surveillance examination.

RESULTS

In 32,535 patients, a lower hazard for PCCRC (n = 178) was observed for higher APCs as compared to APCs of <.25 (reference): .25 to <.40: hazard ratio (HR), .35; 95% confidence interval (CI), .22-.56; .40 to <.50: HR, .31; 95% CI, .20-.49; .50 to <.70: HR, .20; 95% CI, .11-.36; and ≥.70: HR, .19; 95% CI, .09-.37. When examining endoscopists with an ADR of at least 25%, an APC of <.50 was associated with a significantly higher hazard than an APC of ≥.50 (HR, 1.65; 95% CI, 1.06-2.56). A large proportion of endoscopists-one-fifth (32 of 152; 21.1%)-had an ADR of ≥25% but an APC of <.50.

CONCLUSIONS

Our novel data demonstrating lower PCCRC risk in examinations performed by endoscopists with higher APCs suggest that APC could be a useful quality measure. Quality improvement programs may identify important deficiencies in endoscopist detection performance by measuring APC for endoscopists with an ADR of ≥25%.

Colon Polyp Surveillance: Separating the Wheat From the Chaff

One goal of colorectal cancer (CRC) screening is to prevent CRC incidence by removing precancerous colonic polyps, which are detected in up to 50% of screening examinations. Yet, the lifetime risk of CRC is 3.9%-4.3%, so it is clear that most of these individuals with polyps would not develop CRC in their lifetime. It is, therefore, a challenge to determine which individuals with polyps will benefit from follow-up, and at what intervals. There is some evidence that individuals with advanced polyps, based on size and histology, benefit from intensive surveillance. However, a large proportion of individuals will have small polyps without advanced histologic features (ie, "nonadvanced"), where the benefits of surveillance are uncertain and controversial. Demand for surveillance will further increase as more polyps are detected due to increased screening uptake, recent United States recommendations to expand screening to younger individuals, and emergence of polyp detection technology. We review the current understanding and clinical implications of the natural history, biology, and outcomes associated with various categories of colon polyps based on size, histology, and number. Our aims are to highlight key knowledge gaps, specifically focusing on certain categories of polyps that may not be associated with future CRC risk, and to provide insights to inform research priorities and potential management strategies. Optimization of CRC prevention programs based on updated knowledge about the future risks associated with various colon polyps is essential to ensure cost-effective screening and surveillance, wise use of resources, and inform efforts to personalize recommendations.

Post-colonoscopy colorectal cancer: A population-based cohort study of fecal occult blood test-positive colonoscopies

BACKGROUND

Data on post-colonoscopy colorectal cancers (PCCRCs) after fecal occult blood test (FOBT)-positive colonoscopies is scarce (guaiac-based (gFOBT) or fecal immunochemical test (FIT)).

AIMS

Evaluate the prevalence and characteristics of PCCRCs in the French gFOBT CRC screening program.

METHODS

Retrospective population-based cohort study of all gFOBT-positive colonoscopies performed among individuals aged 50-74 between 2003 and 2014 within the CRC screening program organized in the Haut-Rhin (Alsace, France). The main outcome was PCCRC-3y rate. Adenoma detection rates (ADRs) calculated on gFOBT-positive colonoscopies were compared to those calculated on FIT-positive colonoscopies performed by the same gastroenterologists.

RESULTS

Overall, 9106 gFOBT-positive colonoscopies performed by 36 gastroenterologists were included. Sixteen PCCRC-3y and 31 PCCRC-5y were diagnosed (68.8 % and 58.1 % were true interval PCCRCs respectively). The unadjusted PCCRC-3y rate was 2.4 % [95 % confidence interval (CI) 1.4 %-3.9 %]. The risk for PCCRC-5y was significantly higher when the gastroenterologist's ADR was <35 % compared to ≥35 % (HR 2.17 [95 %CI 1.19-3.93]). The mean absolute difference for ADR between gFOBT- and FIT-positive colonoscopies was 16.3 % in favor of FIT-positive colonoscopies.

CONCLUSION

PCCRC-3y prevalence was low, estimated at 2.4 %. We suggest that the minimum standard for ADR in gFOBT- and FIT-positive colonoscopies should be set at 35 % and 50 % to 55 % respectively, in the French screening program.

Impact of AI-aided colonoscopy in clinical practice: a prospective randomised controlled trial

OBJECTIVE

Colorectal cancer (CRC) has a significant role in cancer-related mortality. Colonoscopy, combined with adenoma removal, has proven effective in reducing CRC incidence. However, suboptimal colonoscopy quality often leads to missed polyps. The impact of artificial intelligence (AI) on adenoma and polyp detection rate (ADR, PDR) is yet to be established.

DESIGN

We conducted a randomised controlled trial at Sahlgrenska University Hospital in Sweden. Patients underwent colonoscopy with or without the assistance of AI (AI-C or conventional colonoscopy (CC)). Examinations were performed with two different AI systems, that is, Fujifilm CADEye and Medtronic GI Genius. The primary outcome was ADR.

RESULTS

Among 286 patients, 240 underwent analysis (average age: 66 years). The ADR was 42% for all patients, and no significant difference emerged between AI-C and CC groups (41% vs 43%). The overall PDR was 61%, with a trend towards higher PDR in the AI-C group. Subgroup analysis revealed higher detection rates for sessile serrated lesions (SSL) with AI assistance (AI-C 22%, CC 11%, p=0.004). No difference was noticed in the detection of polyps or adenomas per colonoscopy. Examinations were most often performed by experienced endoscopists, 78% (n=86 AI-C, 100 CC).

CONCLUSION

Amidst the ongoing AI integration, ADR did not improve with AI. Particularly noteworthy is the enhanced detection rates for SSL by AI assistance, especially since they pose a risk for postcolonoscopy CRC. The integration of AI into standard colonoscopy practice warrants further investigation and the development of improved software might be necessary before enforcing its mandatory implementation.

TRIAL REGISTRATION NUMBER

NCT05178095.

Polyp detection rate and cumulative incidence of post-colonoscopy colorectal cancer in Germany

Studies have shown that the quality of colonoscopy influences the incidence of post-colonoscopy colorectal cancer (PCCRC). However, data from Germany on this association are lacking. We aimed to assess cumulative incidence of PCCRC in persons undergoing colonoscopy in Germany according to the physician's polyp detection rate (PDR). Using the German Pharmacoepidemiological Research Database (GePaRD) with claims data of ~20% of the German population, we included persons with a baseline colonoscopy between 2008 and 2017 and categorized them according to the procedure at baseline (snare polypectomy, forceps polypectomy, no polypectomy). In each subgroup, we distinguished between persons examined by physicians with a PDR in the lowest quartile vs higher quartiles and described cumulative CRC incidence during follow-up. Overall, 822 715 persons examined by 1752 physicians were included. One quarter of the physicians had a PDR ≤21.8% (lowest quartile). In all subgroups, the 5-year cumulative CRC incidence was statistically significantly higher in persons examined by physicians with a PDR ≤21.8% vs >21.8%: It was 69% higher in persons with snare polypectomy (0.88% vs 0.52%), 87% higher in persons with forceps polypectomy (0.58% vs 0.31%), and 48% higher in persons without polypectomy at baseline (0.31% vs 0.21%). In conclusion, we found a substantially increased PCCRC risk in persons examined by physicians with a low PDR in Germany, irrespective of the baseline findings. Our study highlights the importance of a high-quality colonoscopy to maximize the preventive effect of colonoscopy on CRC incidence.

Reduced Adenoma Miss Rate With 9-Minute vs 6-Minute Withdrawal Times for Screening Colonoscopy: A Multicenter Randomized Tandem Trial

INTRODUCTION

Although the 9-minute mean withdrawal time (m-WT) is often reported to be associated with the optimal adenoma detection rate (ADR), no randomized trials of screening colonoscopy have confirmed the impact of a 9-minute m-WT on adenoma miss rate (AMR) and ADR.

METHODS

A multicenter tandem trial was conducted in 11 centers. Seven hundred thirty-three asymptomatic participants were randomized to receive segmental tandem screening colonoscopy with a 9-minute withdrawal, followed by a 6-minute withdrawal (9-minute-first group, 9MF, n = 366) or vice versa (6-minute-first group, 6MF, n = 367). The primary outcome was the lesion-level AMR.

RESULTS

The intention-to-treat analysis revealed that 9MF significantly reduced the lesion-level (14.5% vs 36.6%, P < 0.001) and participant-level AMR (10.9% vs 25.9%, P < 0.001), advanced adenoma miss rate (AAMR, 5.3% vs 46.9%, P = 0.002), multiple adenomas miss rate (20.7% vs 56.5%, P = 0.01), and high-risk adenomas miss rate (14.6% vs 39.5%, P = 0.01) of 6MF without compromising detection efficiency ( P = 0.79). In addition, a lower false-negative rate for adenomas ( P = 0.002) and high-risk adenomas ( P < 0.05), and a lower rate of shortening surveillance schedule ( P < 0.001) were also found in 9MF, accompanying with an improved ADR in the 9-minute vs 6-minute m-WT (42.3% vs 33.5%, P = 0.02). The independent inverse association between m-WT and AMR remained significant even after adjusting ADR, and meanwhile, 9-minute m-WT was identified as an independent protector for AMR and AAMR.

DISCUSSION

In addition to increasing ADR, 9-minute m-WT also significantly reduces the AMR and AAMR of screening colonoscopy without compromising detection efficiency.

AGA White Paper: Challenges and Gaps in Innovation for the Performance of Colonoscopy for Screening and Surveillance of Colorectal Cancer

In 2018, the American Gastroenterological Association's Center for GI Innovation and Technology convened a consensus conference, entitled "Colorectal Cancer Screening and Surveillance: Role of Emerging Technology and Innovation to Improve Outcomes." The conference participants, which included more than 60 experts in colorectal cancer, considered recent improvements in colorectal cancer screening rates and polyp detection, persistent barriers to colonoscopy uptake, and opportunities for performance improvement and innovation. This white paper originates from that conference. It aims to summarize current patient- and physician-centered gaps and challenges in colonoscopy, diagnostic and therapeutic challenges affecting colonoscopy uptake, and the potential use of emerging technologies and quality metrics to improve patient outcomes.

Clinically significant serrated polyp detection rates and risk for postcolonoscopy colorectal cancer: data from the New Hampshire Colonoscopy Registry

BACKGROUND AND AIMS

Higher adenoma detection rates reduce the risk of postcolonoscopy colorectal cancer (PCCRC). Clinically significant serrated polyps (CSSPs; defined as any sessile serrated polyp, traditional serrated adenoma, large [≥1 cm] or proximal hyperplastic polyp >5 mm) also lead to PCCRC, but there are no data on associated CSSP detection rates (CSSDRs). We used data from the New Hampshire Colonoscopy Registry (NHCR) to investigate the association between PCCRC risk and endoscopist CSSDR.

METHODS

We included NHCR patients with 1 or more follow-up events: either a colonoscopy or a colorectal cancer (CRC) diagnosis identified through linkage with the New Hampshire State Cancer Registry. We defined our outcome, PCCRC, in 3 time periods: CRC diagnosed 6 to 36 months, 6 to 60 months, or all examinations (6 months or longer) after an index examination. We excluded patients with CRC diagnosed at or within 6 months of the index examination, with incomplete examinations, or with inflammatory bowel disease. The exposure variable was endoscopist CSSDR at the index colonoscopy. Cox regression was used to model the hazard of PCCRC on CSSDR controlling for age, sex, index findings, year of examination, personal history of colorectal neoplasia, and having more than 1 surveillance examination.

RESULTS

One hundred twenty-eight patients with CRC diagnosed at least 6 months after their index examination were included. Our cohort included 142 endoscopists (92 gastroenterologists). We observed that the risk for PCCRC 6 months or longer after the index examination was significantly lower for examinations performed by endoscopists with CSSDRs of 3% to <9% (hazard ratio [HR], .57; 95% confidence interval [CI], .39-.83) or 9% or higher (HR, .39; 95% CI, .20-.78) relative to those with CSSDRs under 3%.

CONCLUSIONS

Our study is the first to demonstrate a lower PCCRC risk after examinations performed by endoscopists with higher CSSDRs. Both CSSDRs of 9% and 3% to <9% had statistically lower risk of PCCRC than CSSDRs of <3%. These data validate CSSDR as a clinically relevant quality measure for endoscopists.

Prevalence of Forceps Polypectomy of Nondiminutive Polyps Is Substantial But Modifiable

BACKGROUND AND AIMS

The use of forceps for removal of nondiminutive polyps is associated with incomplete resection compared with snare polypectomy. However, few studies have characterized the frequency of forceps polypectomy for nondiminutive polyps or identified strategies to improve this practice. To address this gap, we estimated the prevalence and predictors of forceps polypectomy in clinical practice and examined the effectiveness of a multicomponent intervention to reduce inappropriate forceps polypectomy.

METHODS

We retrospectively reviewed all colonoscopies with polypectomies performed at 2 U.S. health systems between October 1, 2017, and September 30, 2019. We used a mixed-effects logistic regression model to examine the effect of a multicomponent intervention, including provider education and a financial incentive, to reduce inappropriate forceps polypectomy, defined as use of forceps polypectomy for polyps ≥5 mm.

RESULTS

A total of 9968 colonoscopies with 25,534 polypectomies were performed by 42 gastroenterologists during the study period. Overall, 8.5% (n = 2176) of polyps were removed with inappropriate forceps polypectomy. Inappropriate forceps polypectomy significantly decreased after the intervention (odds ratio [OR], 0.34, 95% confidence interval [CI], 0.30-0.39), from 11.4% (n = 1539) to 5.3% (n = 637). Predictors of inappropriate forceps polypectomy included inadequate bowel prep (OR, 1.25; 95% CI, 1.06-1.47), polyps in the right colon (vs left: OR, 1.29; 95% CI, 1.09-1.51), and number of polyps removed (OR, 0.96; 95% CI, 0.94-0.97). Inappropriate forceps polypectomy also varied by gastroenterologist (median OR, 3.43). In a post hoc analysis, the proportion of polyps >2 mm removed with forceps decreased from 50.0% before the intervention to 43.0% after it (OR, 0.62; 95% CI, 0.58-0.68).

CONCLUSIONS

Inappropriate forceps polypectomy is common but modifiable. The proportion of nondiminutive polyps removed with forceps polypectomy should be considered as a quality measure.

Bariatric Bypass Surgery Is a Risk Factor for Incomplete Colonoscopy Preparation

OBJECTIVES

Effective colon cancer screening requires adequate bowel preparation. Anecdotal evidence has suggested that patients with a history of bariatric surgery are more likely to have inadequate preparation. This study aims to evaluate the role of bariatric surgery as a predictive risk factor for inadequate bowel preparation.

METHODS

Data were collected retrospectively for consecutive colonoscopies between March 1, 2013, and November 15, 2017. Only the index colonoscopy for each patient within the review period, and those scored using the Boston Bowel Preparation Scale (BBPS) were included. Inadequate preparation was defined as any one or more colon segments with a BBPS score of less than two, and patients with a history of bariatric surgery were identified using ICD 9/10 codes. Multivariate logistic regression and propensity score matching was used to assess for independent factors predictive of inadequate bowel preparation.

RESULTS

A total of 25,318 colonoscopies were included in the analysis. Two hundred 278 (1.1%) patients had a history of bariatric surgery, among which 171 (61.5%) had a history of bypass surgery and 107 (38.5%) had a history of restrictive surgical procedure. A history of bariatric surgery was predictive of inadequate bowel preparation in both univariate (OR: 2.87, 95% CI: 1.92-4.29, P = 0.0003) and multivariate analysis (OR: 2.16, 95% CI: 1.43-3.27, P = 0.0003) after controlling for differences in baseline characteristics. When evaluated separately, a history of bypass surgery was associated with inadequate bowel preparation (aOR: 2.96, 95% CI: 1.86-4.72, P < 0.0001), whereas a history of a restrictive bariatric surgery was not associated with inadequate bowel preparation in multivariate analysis (aOR: 0.98, 95% CI: 0.4-2.45, P = 0.971).

CONCLUSIONS

A history of bariatric surgery is an independent risk factor for inadequate bowel preparation. Furthermore, bypass bariatric surgeries had higher rates of inadequate preparation when compared to restrictive bariatric surgeries. Further quality improvement initiatives should be directed at identifying the appropriate bowel preparation regimen in this population.

Continuous ADR50 monitoring through automated linkage between endoscopy and pathology: a quality improvement initiative in a Brussels public hospital

Background and study aim: Adenoma detection rate in patients aged 50 years or older (ADR50) is considered by the European Society of Gastrointestinal Endoscopy (ESGE) a key performance measures for lower gastrointestinal endoscopy. Technical and human resources constrain implementation of recording quality monitoring. The aim was to deploy an infrastructure for continuous monitoring of endoscopy quality indicators. And to evaluate its potential benefit on quality performance. Methods: A company reporting system was adapted by adding a dedicated tab for quality monitoring, including: preparation, progression, number of resected polyps. Automated linkage with the pathology database resulted in continuous monitoring of inter alia: rate of adequate bowel preparation, cecal intubation rate and ADR50. Continuous monitoring was done for all nine endoscopists working at our center, with individual feedback after 4, 9 and 28 months. Results: A total of 1434 colonoscopies were performed during the first 9 months of monitoring, 682 during the first 4 months, 752 during the following 5 months. Five months after feedback a global increase in ADR50 of 4.6% (22.9% to 27.5%) (P<0.05) was observed, compared to the first 4 months. Thus meeting the benchmark (≥25%) recommended by ESGE. A durable effect of monitoring and feedback was observed after 28 months (ADR50: 29.4%). Conclusions: An easy to use infrastructure for registration of quality monitoring in daily endoscopy practice, automatically linking the pathology database, facilitates continuous monitoring of endoscopy quality indicators. A global and durable ADR50 increase was observed after feedback, considered a quality improvement in performance of lower gastrointestinal endoscopy at our center.

Low-Density Lipoprotein Cholesterol Levels in Coronary Artery Disease Patients: Opportunities for Improvement

Background. We sought to characterize the level of LDL-C control and identify opportunities for improvement and characteristics of patients who were undertreated. Methods. Study patients were from a large multihospital system, age <90, with documentation of at least two encounters with a CAD diagnosis or procedure before a first measured LDL-C level and a last recorded LDL-C measurement over a minimum six-month (median = 22 months, IQR = 15–26 months) follow-up from January 2017 to September 2019. Linear regression analysis for last recorded LDL-C level was used to analyze the effects of statin intensity and patient characteristics. Results. Among 15,111 eligible patients, mean age was 68.4 (SD = 10.8), 68.7% were male, and 79.4% were non-Hispanic White. At follow-up, 87.8% of patients were prescribed a statin, 9.7% were on ezetimibe, and 0.5% were on a PCSK9 inhibitor. Mean LDL-C at follow-up was 75.6 mg/dL and 45.5% of patients were on high-intensity treatment. Higher LDL-C values were associated with female sex, younger patients, non-Hispanic Black patients, high poverty or out of state zip code, Medicaid, or angina as the qualifying diagnosis. For 332 clinicians with >10 patients in the cohort, mean last recorded LDL-C values ranged from 47 to 102 mg/dL. Conclusions. There were important variations in LDL-C control between patients in our health system with the same indication for treatment. Variation in treatment among physicians is an area ripe for quality improvement interventions. This study may be easily reproduced by other medical centers and used for highlighting both patient and physician opportunities for improvement.

Quality Indicators for the Detection and Removal of Colorectal Polyps and Interventions to Improve Them

Modifiable risk factors for postcolonoscopy colorectal cancer include suboptimal lesion detection (missed neoplasms) and inadequate lesion removal (incomplete polypectomy) during colonoscopy. Competent detection and removal of colorectal polyps are thus fundamental to ensuring adequate colonoscopy quality. Several well-researched quality metrics for polyp detection have been implemented into clinical practice, chief among these the adenoma detection rate. Less data are available on quality indicators for polyp removal, which currently include complete resection rates and skills assessment tools. This review summarizes the available literature on quality indicators for the detection and removal of colorectal polyps, as well as interventions to improve them.

Patient and Endoscopic Characteristics of Postcolonoscopy Colon Cancer-A Case-control Study

Background and Aims

Colonoscopy is imperfect for colorectal cancer (CRC) prevention. Postcolonoscopy CRC (PCCRC) is defined as CRC detected after a screening or surveillance colonoscopy. PCCRCs can be divided into noninterval CRC and interval CRC. We performed a case-control study to identify risk factors for PCCRCs and to compare risks between noninterval and interval PCCRCs.

Methods

We designed a retrospective case-control study. Using a Vermont tumor registry data set, we identified all PCCRCs diagnosed at our medical center from January 2012 to September 2017. Cases were matched 1:3 with controls of the same age, sex, and index colonoscopy date.

Results

Fifty-four PCCRCs were matched with 162 controls and divided into noninterval (N = 27) and interval (N = 27) subsets. Overall PCCRC risk and noninterval PCCRC risk were significantly associated with history of polyps (odds ratio [OR] PCCRC = 2.71, OR noninterval = 4.41), sessile serrated polyps (OR PCCRC = 3.94, OR noninterval = 5.79), and high-risk adenoma (HRA) (OR PCCRC = 6.58, OR noninterval = 16.46) and with the index colonoscopy having a large polyp (OR PCCRC = 4.45, OR noninterval = 10.46) or having an HRA (OR PCCRC = 3.68, OR noninterval = 8.04). PCCRC risk and interval PCCRC risk were significantly associated with follow-up recommendations that did not correlate with American Gastroenterological Association surveillance guidelines (OR PCCRC = 3.30, OR interval = 4.85). Approximately 30% of PCCRCs could be attributed to endoscopic quality.

Conclusion

Overall PCCRC risk and noninterval PCCRC risk were significantly associated with traditional CRC risk factors including precancerous polyps and HRA on the index colonoscopy. Interval PCCRC was not associated with these risk factors. Many PCCRCs can be attributed to endoscopic quality, and nonadherence to CRC surveillance guidelines may be a novel risk factor.

Higher Adenoma Detection Rates at Screening Associated With Lower Long-Term Colorectal Cancer Incidence and Mortality

BACKGROUND & AIMS

Detection and removal of adenomas reduces colorectal cancer (CRC) risk. The impact of adenoma detection rates (ADRs) on long-term CRC incidence and mortality is unknown. We investigated this using data from the UK Flexible Sigmoidoscopy Screening Trial.

METHODS

Of 167,882 UK Flexible Sigmoidoscopy Screening Trial participants, 40,085 were in the intervention arm and underwent flexible sigmoidoscopy screening at 13 trial centers. The median follow-up time was 17 years. At each center, 1 endoscopist performed most flexible sigmoidoscopies. Multivariable logistic regression was used to classify centers into high-, intermediate-, and low-detector groups based on their main endoscopist's ADR. We calculated the incidence and mortality of distal and all-site CRC, and estimated hazard ratios (HRs) with 95% CIs using Cox regression.

RESULTS

Five, 4, and 4 centers, respectively, were classified into the high-detector, intermediate-detector, and low-detector groups. The average ADRs in each respective group were 15%, 12%, and 9%. Distal CRC incidence and mortality were reduced among those screened compared with controls in all groups, and effects of screening varied significantly by detector ranking, with larger reductions in incidence and mortality seen in the high-detector group (incidence: HR, 0.34; 95% CI, 0.27-0.42; mortality: HR, 0.22, 95% CI, 0.13-0.37) than in the low-detector group (incidence: HR, 0.55; 95% CI, 0.44-0.68; mortality: HR, 0.54; 95% CI, 0.34-0.86). Similar results were observed for all-site CRC, with larger effects seen in the high-detector (incidence: HR, 0.58; 95% CI, 0.50-0.67; mortality: HR, 0.52; 95% CI, 0.39-0.69) than in the low-detector group (incidence: HR, 0.72; 95% CI, 0.61-0.85; mortality: HR, 0.68; 95% CI, 0.51-0.92), although the heterogeneity was not statistically significant.

CONCLUSIONS

Higher ADRs at screening provide greater long-term protection against CRC incidence and mortality. Isrctn.org, number: ISRCTN28352761.

Molecular pathways in post-colonoscopy versus detected colorectal cancers: results from a nested case-control study

BACKGROUND

Post-colonoscopy colorectal cancers (PCCRCs) pose challenges in clinical practice. PCCRCs occur due to a combination of procedural and biological causes. In a nested case-control study, we compared clinical and molecular features of PCCRCs and detected CRCs (DCRCs).

METHODS

Whole-genome chromosomal copy number changes and mutation status of genes commonly affected in CRC were examined by low-coverage WGS and targeted sequencing, respectively. MSI and CIMP status was also determined.

RESULTS

In total, 122 PCCRCs and 98 DCRCs with high-quality DNA were examined. PCCRCs were more often located proximally (P < 0.001), non-polypoid appearing (P = 0.004), early stage (P = 0.009) and poorly differentiated (P = 0.006). PCCRCs showed significantly less 18q loss (FDR < 0.2), compared to DCRCs. No significant differences in mutations were observed. PCCRCs were more commonly CIMP high (P = 0.014) and MSI (P = 0.029). After correction for tumour location, only less 18q loss remained significant (P = 0.005).

CONCLUSION

Molecular features associated with the sessile serrated lesions (SSLs) and non-polypoid colorectal neoplasms (CRNs) are more commonly seen in PCCRCs than in DCRCs. These together with the clinical features observed support the hypothesis that SSLs and non-polypoid CRNs are contributors to the development of PCCRCs. The future focus should be directed at improving the detection and endoscopic removal of these non-polypoid CRN and SSLs.

CLINICAL TRIAL REGISTRATION

NTR3093 in the Dutch trial register ( www.trialregister.nl ).

Detection of elusive polyps using a large-scale artificial intelligence system (with videos)

BACKGROUND AND AIMS

Colorectal cancer is a leading cause of death. Colonoscopy is the criterion standard for detection and removal of precancerous lesions and has been shown to reduce mortality. The polyp miss rate during colonoscopies is 22% to 28%. DEEP DEtection of Elusive Polyps (DEEP²) is a new polyp detection system based on deep learning that alerts the operator in real time to the presence and location of polyps. The primary outcome was the performance of DEEP² on the detection of elusive polyps.

METHODS

The DEEP² system was trained on 3611 hours of colonoscopy videos derived from 2 sources and was validated on a set comprising 1393 hours from a third unrelated source. Ground truth labeling was provided by offline gastroenterologist annotators who were able to watch the video in slow motion and pause and rewind as required. To assess applicability, stability, and user experience and to obtain some preliminary data on performance in a real-life scenario, a preliminary prospective clinical validation study was performed comprising 100 procedures.

RESULTS

DEEP² achieved a sensitivity of 97.1% at 4.6 false alarms per video for all polyps and of 88.5% and 84.9% for polyps in the field of view for less than 5 and 2 seconds, respectively. DEEP² was able to detect polyps not seen by live real-time endoscopists or offline annotators in an average of .22 polyps per sequence. In the clinical validation study, the system detected an average of .89 additional polyps per procedure. No adverse events occurred.

CONCLUSIONS

DEEP² has a high sensitivity for polyp detection and was effective in increasing the detection of polyps both in colonoscopy videos and in real procedures with a low number of false alarms. (Clinical trial registration number: NCT04693078.).

The quality of screening colonoscopy in rural and underserved areas

BACKGROUND

Screening colonoscopy effectiveness depends on procedure quality; however, knowledge about colonoscopy quality in rural and underserved areas is limited. This study aimed to describe the characteristics and quality of colonoscopy and to examine predictors of colonoscopy quality at rural and underserved hospitals.

METHODS

Adults undergoing colonoscopy from April 2017 to March 2019 at rural or underserved hospitals across the Illinois Surgical Quality Improvement Collaborative were prospectively identified. The primary outcome was colorectal adenoma detection, and secondary outcomes included bowel preparation adequacy, cecum photodocumentation, and withdrawal time. Performance was benchmarked against multisociety guidelines, and multivariable logistic regression was used to examine patient, physician, and procedure characteristics associated with adenoma detection.

RESULTS

In total, 4217 colonoscopy procedures were performed at 8 hospitals, including 1865 screening examinations performed by 19 surgeons, 9 gastroenterologists, and 2 family practitioners. Physician screening volume ranged from 2 to 218 procedures (median 50; IQR 23-74). Adenoma detection occurred in 26.6% of screening procedures (target: ≥ 25%), 90.7% had adequate bowel preparation (target: ≥ 85%), 93.1% had cecum photodocumentation (target: ≥ 95%), and mean withdrawal time was 8.1 min (target: ≥ 6). Physician specialty was associated with adenoma detection (gastroenterologists: 36.9% vs. surgeons: 22.5%; OR 2.30, 95% CI 1.40-3.77), but adequate bowel preparation (OR 1.15, 95% CI 0.76-1.73) and cecum photodocumentation (OR 1.56, 95% CI 0.91-2.69) were not.

CONCLUSION

Colonoscopies performed at rural and underserved hospitals meet many quality metrics; however, quality varied widely. As physicians are scarce in rural and underserved areas, individualized interventions to improve colonoscopy quality are needed.

Risk of post colonoscopy colorectal cancer following screening colonoscopy with low-risk or no adenomas: A population-based study

AIM

In the Danish faecal occult blood test based bowel cancer screening programme, the first round was rolled out over 4 years. After roll-out, the planned faecal test recall procedure for individuals with either no or low risk adenomas at colonoscopy is 8 and 2 years, respectively. Here, we aimed to investigate the post colonoscopy colorectal cancer incidence in these two groups.

METHODS

All Danish screening individuals from 2014 to 2015 with a positive faecal test and either no or low risk adenomas at colonoscopy were included and followed for 3 years post screening for the event of colorectal cancer through national registries.

RESULTS

Out of 533,023 submitted faecal tests and 36,673 positive tests, 17,627 had no or low risk adenomas. We identified 60 (0.34%) individuals diagnosed with colorectal cancer within 3 years, 18 (0.29%) in the low risk adenoma group, and 42 (0.37%) in the no adenomas group (p = 0.44). Advancing age (HR = 1.079, p < 0.001) and higher faecal test value (HR = 1.001, p = 0.002) increased hazard of colorectal cancer occurrence, whereas male sex (HR = 1.3, p = 0.308) and having low risk adenomas (HR = 0.729, p = 0.264) did not.

CONCLUSION

We found no difference in post colonoscopy colorectal cancer occurrence between individuals with either no or low risk adenomas. Instead, advancing age and increased faecal test value was associated with a higher risk of post colonoscopy colorectal cancer.

Educating Outpatients for Bowel Preparation Before Colonoscopy Using Conventional Methods vs Virtual Reality Videos Plus Conventional Methods: A Randomized Clinical Trial

IMPORTANCE

Adequate bowel preparation is essential for diagnostic, screening, and surveillance colonoscopy. Virtual reality (VR) has the characteristics of immersion, interaction, and imagination and has been widely used in medicine for training and teaching, indicating that it could be used in the education of outpatients for bowel preparation before colonoscopy.

OBJECTIVE

To investigate whether using VR videos for patient education before colonoscopy could improve bowel preparation.

DESIGN, SETTING, AND PARTICIPANTS

A prospective, single-blinded, randomized clinical trial of 346 patients undergoing colonoscopy with local anesthesia in a tertiary care hospital was conducted between October 1, 2018, and November 1, 2020. Outpatients who had indications for colonoscopy and had not received one before were enrolled. Statistical analysis was performed from November 1 to December 31, 2020. All data were analyzed according to the intention-to-treat approach.

EXPOSURES

Conventional bowel preparation education (oral instructions and written materials that had the same contents) or conventional education plus VR videos.

MAIN OUTCOMES AND MEASURES

The primary outcome was the quality of bowel preparation measured by the Boston Bowel Preparation Scale score (range, 0-9, where 0 indicates extremely unsatisfactory bowel preparation and 9 indicates complete bowel preparation). Secondary outcomes included polyp and adenoma detection rates, compliance with complete bowel cleansing, preprocedure anxiety, overall satisfaction, and willingness to undergo a follow-up colonoscopy.

RESULTS

A total of 346 outpatients were enrolled in the trial, with 173 patients randomly assigned to each group (control group: 87 women [50.3%]; mean [SD] age, 50.5 [12.5] years; VR video group: 84 women [48.6%]; mean [SD] age, 52.6 [11.4] years). Baseline characteristics, including demographic information, medical history, lifestyle, and the characteristics of stool, were comparable between the VR video group and the control group. The mean (SD) Boston Bowel Preparation Scale score was significantly higher in the VR video group than in the control group (7.61 [1.65] vs 7.04 [1.70]; P = .002). The detection rate of polyps (72 of 172 [41.9%] vs 46 of 172 [26.7%]; P = .003) and the detection rate of adenomas (56 of 172 [32.6%] vs 38 of 172 [22.1%]; P = .03) were also higher in the VR video group. Patients who received VR education had better compliance (119 [68.8%] vs 87 [50.3%]; P < .001) and higher mean (SD) overall satisfaction (8.68 [1.70] vs 8.16 [2.15]; P = .01) with bowel preparation.

CONCLUSIONS AND RELEVANCE

Patients who received VR video education before colonoscopy had better bowel preparation, higher polyp and adenoma detection rates, and improved compliance and satisfaction.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03667911.

AGA Clinical Practice Update on Strategies to Improve Quality of Screening and Surveillance Colonoscopy: Expert Review

The purpose of this American Gastroenterological Association Institute Clinical Practice Update was to review the available evidence and provide best practice advice regarding strategies to improve the quality of screening and surveillance colonoscopy. This review is framed around 15 best practice advice statements regarding colonoscopy quality that were agreed upon by the authors, based on a review of the available evidence and published guidelines. This is not a formal systematic review and thus no formal rating of the quality of evidence or strength of recommendation has been carried out.

Impact of the National Endoscopy Database (NED) on colonoscopy withdrawal time: a tertiary centre experience

OBJECTIVE

Colonoscopy withdrawal time (CWT) is a key performance indicator affecting polyp detection rate (PDR) and adenoma detection rate (ADR). However, studies have shown wide variation in CWT and ADR between different endoscopists. The National Endoscopy Database (NED) was implemented to enable quality assurance in all endoscopy units across the UK and also to reduce variation in practice. We aimed to assess whether CWT changed since the introduction of NED and whether CWT affected PDR.

METHODS

We used NED to retrospectively collect data regarding CWT and PDR of 25 endoscopists who performed (n=4459 colonoscopies) in the four quarters of 2019. We then compared this data to their performance in 2016, before using NED (n=4324 colonoscopies).

RESULTS

Mean CWT increased from 7.66 min in 2016 to 9.25 min in 2019 (p=0.0001). Mean PDR in the two periods was 29.9% and 28.3% (p=0.64). 72% of endoscopists (18/25) had CWT>6 min in 2016 versus 100% (25/25) in 2019, the longer CWT in 2019 positively correlated with the PDR (r=0.50, p=0.01). Gastroenterology consultants and trainee endoscopists had longer CWT compared with colorectal surgeons both before and after using NED.

CONCLUSION

NED usage increased withdrawal times in colonoscopy. Longer withdrawal times were associated with higher PDR. A national colonoscopy audit using data from NED is required to evaluate whether wide variations in practice across endoscopy units in the UK still exist and to ensure minimum colonoscopy quality standards are achieved.

Simple feedback of colonoscopy performance improved the number of adenomas per colonoscopy and serrated polyp detection rate

Background and study aims  High-quality endoscopy requires improvement of not only the adenoma detection rate (ADR) but also the serrated polyp (SP) detection rate and the mean number of adenomas per positive procedure (MAP +). We evaluated whether a simple feedback of colonoscopy performance improves those quality indicators using propensity-score matching. Patients and methods  Eleven endoscopists were evaluated regarding colonoscopy performance including ADRs, SP detection rates, mean numbers of adenomas per procedure (MAPs), and MAPs + with their ranking in the clinic. Endoscopic performance was compared before and after the feedback. Results  Colonoscopies were performed for 874 patients before the feedback and 1,272 patients after the feedback. Using propensity-score matching, 803 patients before the feedback and 803 patients after the feedback were matched. ADR after the feedback was significantly higher than that before the feedback (50.8 % and 40.8 %, respectively). MAP after feedback was significantly larger than that before the feedback (0.92 and 0.69, respectively), as well as MAP + (1.96 and 1.69, respectively). Clinically significant SP detection rate was also improved from 10.0 % to 14.9 %. Conclusions  Feedback including ADR, MAP, MAP +, and clinically significant SR detection rate could improve on those quality indicators. Further studies are needed to effectively prevent colorectal cancer in colonoscopy practice.

Age, male sex, smoking and metabolic syndrome as risk factors of advanced colorectal neoplasia for fecal immunochemical test negative patients

BACKGROUND

Fecal immunochemical test (FIT) is worldwide strategy for colorectal cancer screening. The subjects with negative FIT still have the risk of an advanced colorectal neoplasia (AN), including adenoma with villous histology, high grade dysplasia or larger than 1 cm in size, or adenocarcinoma. The study determined the risk factors associated with AN in FIT-negative subjects.

METHODS

The study included asymptomatic subjects who received health checkup colonoscopy and have provided FIT study within 6 months prior to colonoscopy. The risk factors to have AN in cases with negative FIT were analyzed. The numbers of colonoscopies needed to detect one AN were calculated for the subjects with different risk factors.

RESULTS

There were 1411 cases, 85 with positive FIT and 1326 with negative FIT within 6 months before colonoscopy. In FIT positive and FIT negative cases, 45.9% and 34.6% were found to have colorectal adenoma, while 20.2% and 4.6% had AN, respectively. The univariate and multivariate logistic regression analyses showed that age more than 50 years old, male sex, smoking history and metabolic syndrome were the significant risk factors to have AN in the FIT negative cases. For cases with negative FIT to have these risk factors, the number of colonoscopies needed to detect one AN was 3.7, lower than 4.5 of the cases with positive FIT.

CONCLUSION

For the cases with negative FIT, colonoscopy screening should be considered for those male patients over 50 years old, with a history of smoking and metabolic syndrome to detect AN.

Feasibility and safety of colonoscopy performed by nonexperts for acute lower gastrointestinal bleeding: post hoc analysis

Background and study aims  It remains unclear whether the experience of endoscopists affects clinical outcomes for acute lower gastrointestinal bleeding (ALGIB). We aimed to determine the feasibility and safety of colonoscopies performed by nonexperts using secondary data from a randomized controlled trial for ALGIB. Patients and methods  We analyzed clinical outcomes in 159 patients with ALGIB who underwent colonoscopies performed by two groups of endoscopists: experts and nonexperts. We compared endoscopy outcomes, including identification of stigmata of recent hemorrhage (SRH), successful endoscopic treatment, adverse events (AEs), and clinical outcomes between the two groups, including 30-day rebleeding, transfusion, length of stay, thrombotic events, and 30-day mortality. Results  Expert endoscopists alone performed colonoscopies in 96 patients, and nonexperts performed colonoscopies in 63 patients. The use of antiplatelets and warfarin was significantly higher in the expert group. The SRH identification rate (24.0 and 17.5 %), successful endoscopic treatment rate (95.0 and 100 %), rate of AEs during colonoscopy (0 and 0 %), transfusion rate (6.3 and 4.8 %), length of stay (8.0 and 6.4 days), rate of thrombotic events (0 and 1.8 %), and mortality (0 and 0 %) were not different between the expert and nonexpert groups. Rebleeding within 30 days occurred more often in the expert group than in the nonexpert group (14.3 vs. 5.4 % P  = 0.0914). Conclusions  The performance of colonoscopies for ALGIB by nonexperts did not result in worse clinical outcomes, suggesting that its use could be feasible for nonexperts for diagnosis and treatment of ALGIB.

Interval Colorectal Cancer 2006-2015: Novel Observations

BACKGROUND

Screening for colorectal cancer (CRC) with colonoscopy has been credited for the majority of the decline in mortality over the past 40 years. However, colonoscopy is hampered by frequent interval cancers (ICs) occurring within 36 months after the last examination. Risk factors for IC imply that most misses are amenable to improved colonoscopic techniques. This study had two primary objectives: (1) to determine whether the proportion of persons with ICs has declined in association with improved approaches to the quality of colonoscopy and (2) to determine unrecognized causes for missed diagnoses.

METHODS

This is a retrospective, single-center study of persons with CRC having been diagnosed within 6-36 months since the most recent colonoscopy between 2006 and 2015. Participants, ages 50 and 89 years, were evaluated specifically for technical features and findings of the most recent colonoscopy.

RESULTS

Thirty-nine persons met the inclusion criteria for IC. Mean age was 69.3 years, range 50-86 years, women were 58%, races included 95% Caucasian, 2.5% Asian, and 2.5% African-American, and history of a first-degree relative with CRC was 26%. Symptoms led to the interval diagnosis in 83%, including iron-deficient anemia (38%), bleeding (25%), abdominal/pelvic pain (18%), and change in bowel habit (2.5%). Preexisting neoplasia was present in 72%. The CRC was located in the proximal colon in 51%. Late-stage disease was present in 45%. When compared to persons with an initial diagnosis of screen-detected late-onset CRC, differences were noted for older age, more women, more with a family history of CRC, and more with late-stage disease. The ratio of interval cancers to new cancers ranged between 6 and 11.5%. Findings indicating a "difficult examination" were observed in 14 cases (36%) compared to "easy or no difficulty" examinations in 25 (65%) cases. In a biennial analysis of IC rates between 2006 and 2015, the percentage of IC remained stable between 6 and 11.5%.

CONCLUSIONS

ICs have been stable constituting 6-11.5% of all CRCs. A "difficult examination" was often associated with IC, may be a risk factor for this problem, and may be an important clue warranting further study.

Improvement in adenoma detection using a novel artificial intelligence-aided polyp detection device

Background and study aims  Detecting colorectal neoplasia is the goal of high-quality screening and surveillance colonoscopy, as reflected by high adenoma detection rate (ADR) and adenomas per colonoscopy (APC). The aim of our study was to evaluate the performance of a novel artificial intelligence (AI)-aided polyp detection device, Skout, with the primary endpoints of ADR and APC in routine colonoscopy. Patients and methods  We compared ADR and APC in a cohort of outpatients undergoing routine high-resolution colonoscopy with and without the use of a real-time, AI-aided polyp detection device. Patients undergoing colonoscopy with Skout were enrolled in a single-arm, unblinded, prospective trial and the results were compared with a historical cohort. All resected polyps were examined histologically. Results  Eighty-three patients undergoing screening and surveillance colonoscopy at an outpatient endoscopy center were enrolled and outcomes compared with 283 historical control patients. Overall, ADR with and without Skout was 54.2 % and 40.6 % respectively ( P  = 0.028) and 53.6 % and 30.8 %, respectively, in screening exams ( P  = 0.024). Overall, APC rate with and without Skout was 1.46 and 1.01, respectively, ( P  = 0.104) and 1.18 and 0.50, respectively, in screening exams ( P  = 0.002). Overall, true histology rate (THR) with and without Skout was 73.8 % and 78.4 %, respectively, ( P  = 0.463) and 75.0 % and 71.0 %, respectively, in screening exams ( P  = 0.731). Conclusion  We have demonstrated that our novel AI-aided polyp detection device increased the ADR in a cohort of patients undergoing screening and surveillance colonoscopy without a significant concomitant increase in hyperplastic polyp resection. AI-aided colonoscopy has the potential for improving the outcomes of patients undergoing colonoscopy.

Development of an automated ERCP Quality Report Card using structured data fields

Background and aims

Measuring adherence to ERCP quality indicators (QIs) is confounded by variability in indications, maneuvers, and documentation styles. We hypothesized that incorporation of mandatory, structured data fields within reporting software would permit accurate measurement of QI adherence rates and facilitate generation of a provider ERCP report card.

Methods

At two referral centers, endoscopy documentation software was modified to generate provider alerts prior to finalizing the note. The alerts reminded the provider to document the following components in a standardized manner: indication, altered anatomy, prior interventions, and QIs deemed high priority by society consensus, study authors, or both. Adherence rates for each QI were calculated in aggregate and by provider via data extraction directly from the procedure documentation software. Medical records were reviewed manually to measure the accuracy of automated data extraction. Accuracy of automated measurement for each QI was calculated against results derived by manual review.

Results

During the 9-month study period, 1,376 ERCP procedures were completed by 8 providers. Manual medical record review confirmed high (98-100%) accuracy of automatic extraction of ERCP QIs from the endoscopy report, including cannulation rate of the native papilla and complete extraction of common bile duct stones. An ERCP report card was generated, allowing for individual comparison of adherence to ERCP QIs with colleagues at their institution and others.

Conclusion

In this pilot study, use of mandatory, structured data fields within clinical ERCP reports permit the accurate measurement of high priority ERCP QIs and the subsequent generation of interval report cards.

Adenoma detection rate is not influenced by the time of day in computer-aided detection colonoscopy

Because of endoscopist fatigue, the time of colonoscopy have been shown to influence adenoma detection rate (ADR). Computer-aided detection (CADe) provides simultaneous visual alerts on polyps during colonoscopy and thus to increase adenoma detection rate. This is attributable to the strengthening of endoscopists diagnostic level and alleviation of fatigue. The aim of the study was to investigate whether CADe colonoscopy could eliminate the influence of the afternoon fatigue on ADR.We retrospectively analyzed the recorded data of patients who were performed CADe colonoscopy from September 2017 to February 2019 in Endoscopy Center of Sichuan Provincial People's Hospital. Patients demographic as well as baseline data recorded during colonoscopy were used for the analysis. Morning colonoscopy was defined as colonoscopic procedures starting between 8:00 am and 12:00 noon. Afternoon colonoscopy was defined as procedures starting at 2:00 pm and thereafter. The primary outcome was ADR. Univariate analysis and multivariate regression analysis were also performed.A total of 484 CADe colonoscopies were performed by 4 endoscopists in the study. The overall polyp detection rate was 52% and overall ADR was 35.5%. The mean number of adenomas detected per colonoscopy (0.62 vs 0.61, P > .05) and ADR (0.36 vs 0.35, P > .05) were similar in the am and pm group. Multivariable analysis shows that the ADR of CADe colonoscopy was influenced by the age (P < .001), gender (P = .004) and withdrawal time (P < .001), no correlation was found regarding bowel preparation (P = .993) and endoscopist experience (P = .804).CADe colonoscopy could eliminate the influence of the afternoon fatigue on ADR. The ADR during CADe colonoscopy is significantly affected by age, gender and withdrawal time.

Improved detection of adenomas and sessile serrated polyps is maintained with continuous audit of colonoscopy

BACKGROUND

The audit process may help improve performance indicators for colonoscopy quality but it is unclear whether this is sustained over several years.

METHODS

44138 procedures for 28 endoscopists from 2004 to 2019 were analysed for polyp detection rate and withdrawal time. From 2012, 14 endoscopists were analysed with additional data on polyp histology and number of polyps removed.

RESULTS

Polyp detection increased from 40.7% in 2004 to 62.2% in 2019; removal of polyps>1 cm remained constant (11%). Adenoma detection rate was 25.8% in 2012 and 28.3% in 2019. Sessile serrated polyp (SSP) detection rate increased from 4.5% to 14.7%; most of the increase was in the first 2 years of the histology part of the audit. There was a significant correlation of adenoma detection rate with mean number of adenomas (r=0.72, p=0.004) and a significant correlation of SSP detection with mean number of SSPs (r=0.85, p=0.0001).

CONCLUSION

The audit process appears to encourage a higher rate of polyp detection. This was due to increased detection of smaller polyps and increased detection of SSPs.