Impact of the COVID-19 Pandemic on Fecal Immunochemical Testing, Colonoscopy Services, and Colorectal Neoplasia Detection in a Large United States Community-based Population.

BACKGROUND & AIMS: The COVID-19 pandemic has affected clinical services globally, including colorectal cancer (CRC) screening and diagnostic testing. We investigated the pandemic's impact on fecal immunochemical test (FIT) screening, colonoscopy utilization, and colorectal neoplasia detection across 21 medical centers in a large integrated health care organization. METHODS: We performed a retrospective cohort study in Kaiser Permanente Northern California patients ages 18 to 89 years in 2019 and 2020 and measured changes in the numbers of mailed, completed, and positive FITs; colonoscopies; and cases of colorectal neoplasia detected by colonoscopy in 2020 vs 2019. RESULTS: FIT kit mailings ceased in mid-March through April 2020 but then rebounded and there was an 8.7% increase in kits mailed compared with 2019. With the later mailing of FIT kits, there were 9.0% fewer FITs completed and 10.1% fewer positive tests in 2020 vs 2019. Colonoscopy volumes declined 79.4% in April 2020 compared with April 2019 but recovered to near pre-pandemic volumes in September through December, resulting in a 26.9% decline in total colonoscopies performed in 2020. The number of patients diagnosed by colonoscopy with CRC and advanced adenoma declined by 8.7% and 26.9%, respectively, in 2020 vs 2019. CONCLUSIONS: The pandemic led to fewer FIT screenings and colonoscopies in 2020 vs 2019; however, after the lifting of shelter-in-place orders, FIT screenings exceeded, and colonoscopy volumes nearly reached numbers from those same months in 2019. Overall, there was an 8.7% reduction in CRC cases diagnosed by colonoscopy in 2020. These data may help inform the development of strategies for CRC screening and diagnostic testing during future national emergencies.

Interactive training versus self-driven training in the prediction of colorectal polyp histology by trainees using the NICE classification.

BACKGROUND: The COVID-19 pandemic has impacted endoscopic training of the Narrow Band Imaging International Colorectal Endoscopic (NICE) classification, which could accurately predict pathology of colorectal polyps. This study aimed to evaluate the diagnostic performance by trainees of self-driven training vs. interactive training in the prediction of colorectal polyp histology. METHODS: This was a prospective randomized controlled study at five academic centers from January 1, 2021 to May 31, 2021. Trainees with no previous formal training of narrow band imaging or blue light imaging for prediction of colorectal polyp histology were randomly allocated to the self-driven training group or interactive training group. Before and after the training, all trainees were given 20 selected cases of colorectal polyp for testing. Their diagnostic performance was analyzed. RESULTS: Overall, the two training groups showed similar accuracy of NICE classification (79.3% vs. 78.1%; P = 0.637), vessel analysis (77.8% vs. 77.6%, P = 0.939), and surface pattern analysis (78.1% vs. 76.9%, P = 0.616). The accuracy of color analysis in the interactive training group was better (74.4% vs. 80.0%, P = 0.027). For high-confidence predictions, the self-driven training group showed higher accuracy of NICE classification (84.8% vs. 78.7%, P < 0.001) but no difference for analysis of color (79.6% vs. 81.0%), vessel pattern (83.0% vs. 78.5%), and surface pattern (81.8% vs. 78.5%). CONCLUSIONS: Overall, self-driven training showed comparable accuracy of NICE classification, vessel pattern, and surface pattern to interactive training, but lower accuracy of color analysis. This method showed comparable effectiveness and is more applicable than interactive training. It is worth spreading during the COVID-19 pandemic. Trial registration Name of the registry: Chinese Clinical Trial Registry, Trial registration number: ChiCTR2000031659, Date of registration: 06/04/2020, URL of trial registry record: http://www.chictr.org.cn/showproj.aspx?proj=51994.

Rates of Follow-up Colonoscopy After a Positive Stool-Based Screening Test Result for Colorectal Cancer Among Health Care Organizations in the US, 2017-2020.

Importance: Noninvasive stool-based screening tests (SBTs) are effective alternatives to colonoscopy. However, a positive SBT result requires timely follow-up colonoscopy (FU-CY) to complete the colorectal cancer screening paradigm. Objectives: To evaluate FU-CY rates after a positive SBT result and to assess the association of the early COVID-19 pandemic with FU-CY rates. Design, Setting, and Participants: This mixed-methods cohort study included retrospective analysis of deidentified administrative claims and electronic health records data between June 1, 2015, and June 30, 2021, from the Optum Labs Data Warehouse and qualitative, semistructured interviews with clinicians from 5 health care organizations (HCOs). The study population included data from average-risk primary care patients aged 50 to 75 years with a positive SBT result between January 1, 2017, and June 30, 2020, at 39 HCOs. Main Outcomes and Measures: The primary outcome was the FU-CY rate within 1 year of a positive SBT result according to patient age, sex, race, ethnicity, insurance type, Charlson Comorbidity Index (CCI), and prior SBT use. Results: This cohort study included 32 769 individuals (16 929 [51.7%] female; mean [SD] age, 63.1 [7.1] years; 2092 [6.4%] of Black and 28 832 [88.0%] of White race; and 825 [2.5%] of Hispanic ethnicity). The FU-CY rates were 43.3% within 90 days of the positive SBT result, 51.4% within 180 days, and 56.1% within 360 days (n = 32 769). In interviews, clinicians were uniformly surprised by the low FU-CY rates. Rates varied by race, ethnicity, insurance type, presence of comorbidities, and SBT used. In the Cox proportional hazards regression model, the strongest positive association was with multitarget stool DNA use (hazard ratio, 1.63 [95% CI, 1.57-1.68] relative to fecal immunochemical tests; P < .001), and the strongest negative association was with the presence of comorbidities (hazard ratio, 0.64 [95% CI, 0.59-0.71] for a CCI of >4 relative to 0; P < .001). The early COVID-19 pandemic was associated with lower FU-CY rates. Conclusions and Relevance: This study found that FU-CY rates after a positive SBT result for colorectal cancer screening were low among an average-risk population, with the median HCO achieving a 53.4% FU-CY rate within 1 year. Socioeconomic factors and the COVID-19 pandemic were associated with lower FU-CY rates, presenting opportunities for targeted intervention by clinicians and health care systems.

Artificial Intelligence-Aided Colonoscopy Does Not Increase Adenoma Detection Rate in Routine Clinical Practice.

The performance of artificial intelligence-aided colonoscopy (AIAC) in a real-world setting has not been described. We compared adenoma and polyp detection rates (ADR/PDR) in a 6-month period before (pre-AIAC) and after introduction of AIAC (GI Genius, Medtronic) in all endoscopy suites in our large-volume center. The ADR and PDR in the AIAC group was lower compared with those in the pre-AIAC group (30.3% vs 35.2%, P < 0.001; 36.5% vs 40.9%, P = 0.004, respectively); procedure time was significantly shorter in the AIAC group. In summary, introduction of AIAC did not result in performance improvement in our large-center cohort, raising important questions on AI-human interactions in medicine.

A Novel Convolutional Neural Network Model as an Alternative Approach to Bowel Preparation Evaluation Before Colonoscopy in the COVID-19 Era: A Multicenter, Single-Blinded, Randomized Study.

INTRODUCTION: Adequate bowel preparation is key to a successful colonoscopy, which is necessary for detecting adenomas and preventing colorectal cancer. We developed an artificial intelligence (AI) platform using a convolutional neural network (CNN) model (AI-CNN model) to evaluate the quality of bowel preparation before colonoscopy. METHODS: This was a colonoscopist-blinded, randomized study. Enrolled patients were randomized into an experimental group, in which our AI-CNN model was used to evaluate the quality of bowel preparation (AI-CNN group), or a control group, which performed self-evaluation per routine practice (control group). The primary outcome was the consistency (homogeneity) between the results of the 2 methods. The secondary outcomes included the quality of bowel preparation according to the Boston Bowel Preparation Scale (BBPS), polyp detection rate, and adenoma detection rate. RESULTS: A total of 1,434 patients were enrolled (AI-CNN, n = 730; control, n = 704). No significant difference was observed between the evaluation results ("pass" or "not pass") of the groups in the adequacy of bowel preparation as represented by BBPS scores. The mean BBPS scores, polyp detection rate, and adenoma detection rate were similar between the groups. These results indicated that the AI-CNN model and routine practice were generally consistent in the evaluation of bowel preparation quality. However, the mean BBPS score of patients with "pass" results were significantly higher in the AI-CNN group than in the control group, indicating that the AI-CNN model may further improve the quality of bowel preparation in patients exhibiting adequate bowel preparation. DISCUSSION: The novel AI-CNN model, which demonstrated comparable outcomes to the routine practice, may serve as an alternative approach for evaluating bowel preparation quality before colonoscopy.

Successful mRNA COVID-19 Vaccination and Colonoscopy After Oral Desensitization in a Patient With Polyethylene Glycol Allergy.

Anaphylaxis to polyethylene glycol (PEG) is rare and mainly occurs with the use of laxatives containing PEG. Recently, an increasing number of PEG allergies have been reported, particularly those related to coronavirus disease 2019 (COVID-19) vaccines. mRNA COVID-19 vaccines, such as the BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines, contain PEG2000 as an excipient and are contraindicated when allergy to a vaccine component exist. We report a 55-year-old woman's history as a case of successful mRNA COVID-19 vaccination and colonoscopy after oral desensitization to PEG in a patient with PEG allergy who required both COVID-19 vaccination and colon evaluation. Allergy to PEG was diagnosed based on clinical history, skin test results, and basophil histamine release testing. Oral desensitization effectively suppressed histamine release from basophils in response to PEG stimulation, suggesting that oral desensitization using PEG-based laxatives may be an effective treatment option for patients with allergy to the substance.

Impact of social determinants of health on colorectal cancer screening and surveillance in the COVID reopening phase.

BACKGROUND/AIMS: Procedural delays due to the coronavirus disease 2019 (COVID-19) pandemic may exacerbate disparities in colorectal cancer (CRC) preventive care. We aimed to measure racial and socioeconomic disparities in the prioritization of CRC screening or adenoma surveillance during the COVID reopening period. METHODS: We identified CRC screening or surveillance colonoscopies performed during two time periods: (1) 9 June 2019-30 September 2019 (pre-COVID) and (2) 9 June 2020-30 September 2020 (COVID reopening). We recorded the procedure indication, patient age, sex, race/ethnicity, primary language, insurance status and zip code. Multivariable logistic regression was used to determine factors independently associated with undergoing colonoscopy in the COVID reopening era. RESULTS: We identified 1473 colonoscopies for CRC screening or adenoma surveillance; 890 occurred in the pre-COVID period and 583 occurred in the COVID reopening period. In total 342 (38.4%) pre-COVID patients underwent adenoma surveillance and 548 (61.6%) underwent CRC screening; in the COVID reopening cohort, 257 (44.1%) underwent adenoma surveillance and 326 (55.9%) underwent CRC screening (P = 0.031). This increased proportion of surveillance procedures in the reopening cohort was statistically significant on multivariable analysis [odds ratio (OR), 1.26; 95% confidence interval (CI), 1.001-1.58]. Black patients comprised 17.4% of the pre-COVID cohort, which declined to 15.3% (P = 0.613). There was a trend toward an inverse association between reopening phase colonoscopy and Medicaid insurance compared with commercial insurance (OR, 0.71; 95% CI, 0.49-1.04). No significant associations were found between reopening phase colonoscopy and the remaining variables. CONCLUSIONS: During the COVID reopening period, colonoscopies for CRC fell by over one-third with significantly more surveillance than screening procedures. Nonwhite patients and non-English speakers comprised a shrinking proportion in the COVID reopening period.

Effect of enhanced personal protective equipment on colonoscopy performance and pain linked to procedure during the COVID-19 pandemic.

Background and study aim: During the COVID-19 pandemic, the use of standard personal protective equipment (SPPE) reduces transmission risks during endoscopic procedures. Our aim was to assess the effect of enhanced personal protective equipment (EPPE) on colonoscopy performance and pain linked to the procedure compared with SPPE. Patients and methods: During two similar periods with three-month duration (in 2019 and in 2020 during the COVID-19 pandemic), electronic medical records and colonoscopy reports were investigated for sequential patients undergoing colonoscopy. SPPE was used in 2019 and EPPE in 2020. The patients' clinical data and information related to the procedure were collected and analyzed. Primary outcomes were the duration to intubate the cecum, total procedure duration and patient pain score at the end of the procedure. Secondary outcomes were adenoma detection rate (ADR), polyp detection rate (PDR) and cecal intubation rate (CIR). Results: A total of 426 patients with colonoscopy performed were analyzed. The demographic features and indications for colonoscopy were similar for patients in both groups. The EPPE group had higher values for the parameters assessed as primary endpoints of cecal intubation time, withdrawal time, total procedure time and pain at the end of the procedure compared to the SPPE group and the differences were statistically significant. Conclusion: Our findings show that though the use of EPPE negatively affected colonoscopy performance and patient pain at the end of the procedure, it had no effect on the colonoscopy quality indices such as ADR, PDR and CIR.

Colonoscopic-Assisted Laparoscopic Wedge Resection for Colonic Lesions: A Prospective Multicenter Cohort Study (LIMERIC-Study).

OBJECTIVE: The aim of this study was to evaluate the safety and efficacy of a modified CAL-WR. SUMMARY BACKGROUND DATA: The use of segmental colectomy in patients with endoscopically unresectable colonic lesions results in significant morbidity and mortality. CAL-WR is an alternative procedure that may reduce morbidity. METHODS: This prospective multicenter study was performed in 13 Dutch hospitals between January 2017 and December 2019. Inclusion criteria were (1) colonic lesions inaccessible using current endoscopic resection techniques (judged by an expert panel), (2) non-lifting residual/recurrent adenomatous tissue after previous polypectomy or (3) an undetermined resection margin after endoscopic removal of a low-risk pathological T1 (pT1) colon carcinoma. Thirty-day morbidity, technical success rate and radicality were evaluated. RESULTS: Of the 118 patients included (56% male, mean age 66 years, standard deviation ± 8 years), 66 (56%) had complex lesions unsuitable for endoscopic removal, 34 (29%) had non-lifting residual/recurrent adenoma after previous polypectomy and 18 (15%) had uncertain resection margins after polypectomy of a pT1 colon carcinoma. CAL-WR was technically successful in 93% and R0 resection was achieved in 91% of patients. Minor complications (Clavien-Dindo i-ii) were noted in 7 patients (6%) and an additional oncologic segmental resection was performed in 12 cases (11%). Residual tissue at the scar was observed in 5% of patients during endoscopic follow-up. CONCLUSIONS: CAL-WR is an effective, organ-preserving approach that results in minor complications and circumvents the need for major surgery. CAL-WR, therefore, deserves consideration when endoscopic excision of circumscribed lesions is impossible or incomplete.

The impact of delaying colonoscopies during the COVID-19 pandemic on colorectal cancer detection and prevention.

PURPOSE: The COVID-19 pandemic resulted in a partial to total shutdown of endoscopy in many healthcare centers. This study aims to quantify the impact of the reduction in colonoscopies on colorectal cancer (CRC) detection and screening. METHODS: After institutional ethics board approval, the endoscopy database at an academic tertiary-care center in Montreal, Canada, was searched for all colonoscopies performed from during the first wave locally (March-June 2020), and during the ramp up period where endoscopy service resumed (July to August 2020). We compared these periods to the same periods in 2019, the pre-pandemic periods. The indications, CRC and adenoma detection rates, as well as the prioritization of urgent procedures were compared. RESULTS: In the first wave, only 462 colonoscopies were performed, compared to 2515 in the same period in 2019, an 82% reduction. The ramp up period saw 843 colonoscopies performed compared to 1328 in 2019, a 35% reduction. Urgent and inpatient colonoscopies numbers increased (324 (24.8%) vs. 220 (5.7%)) while surveillance and high-risk screening colonoscopies fell (376 (28.8%) vs 1869 (48.6%)). Emergency access to colonoscopy was preserved with a median time to endoscopy of < 1 day (IQR 0,1) in both pandemic periods. During the pandemic periods, there was an absolute reduction in CRC diagnosis of 28, despite the CRC detection per colonoscopy rate increasing slightly in the first wave from 1.7% (44) to 3.9% (18), and in the ramp up period from 2.5% (33) to 3.6% (31). The rate of adenoma detection per colonoscopy did not increase significantly between the pre- and pandemic periods, resulting in reduction in adenoma removal in 723 patients. DISCUSSION: The restriction of access to colonoscopy resulted in a significant reduction in screening and surveillance of high-risk patients, adenomas removed, and CRCs diagnosed. Clinicians and patients will face the oncologic ramifications this the coming years.

Faecal immunochemical test mitigates risk of delayed colonoscopy in people with elevated risk of colorectal neoplasia.

BACKGROUND AND AIM: Surveillance colonoscopies may be delayed because of pressure on resources, such as the COVID-19 pandemic. This study aimed to determine whether delayed surveillance colonoscopy increases the risk for advanced neoplasia and whether interval screening with faecal immunochemical tests (FITs) and other known risk factors can mitigate this risk. METHODS: A retrospective cohort study of individuals undergoing surveillance colonoscopy for personal or family history of colorectal neoplasia was being provided with FIT between colonoscopies. Colonoscopy ≥ 6 months after the guideline-recommended interval was considered "delayed." Individuals were stratified based on prime colonoscopy findings to nonneoplastic findings, non-advanced adenoma, and advanced adenoma. The relative risk (RR) for developing advanced neoplasia was determined using a robust multivariable modified Poisson regression. RESULTS: Of 2548 surveillance colonoscopies, 1457 (57.18%) were delayed. Prior advanced adenoma, older age (> 60 years) and nonparticipation in interval FIT were associated with increased risk for advanced neoplasia (P < 0.05). There was a trend to increased risk in those with prior advanced adenoma with an increasing colonoscopy delay (P trend = 0.01). In participants who did not complete interval FIT and having advanced adenoma in the prime colonoscopy, risk of advanced neoplasia was 2.48 times higher (RR = 2.48, 95% confidence interval: 1.20-5.13) in participants who had beyond 2 years of delayed colonoscopy compared with those with on-time colonoscopy. Colonoscopy delay did not increase the risk of advanced neoplasia in participants with negative interval FIT results. CONCLUSION: Surveillance colonoscopy can be safely extended beyond 6 months in elevated colorectal cancer risk patients who do not have prior advanced adenoma diagnosis, particularly if interval FIT is negative.

Systematic review and meta-analysis of colon capsule endoscopy accuracy for colorectal cancer screening. An alternative during the Covid-19 pandemic?

AIM: To determine the diagnostic accuracy of colon capsule endoscopy for colorectal cancer screening. METHODS: Studies that compared the diagnostic performance of colonoscopy and second-generation colon capsule endoscopy (CCE-2) for screening of asymptomatic patients aged 50-75 years were included. The primary outcomes were sensitivity, specificity, and positive and negative likelihood ratios for polyps and adenomas measuring at least 6 mm or 10 mm. RESULTS: Eight full-text studies that evaluated 1602 patients were included for systematic review. Of these, 840 (52.43%) patients participated in an opportunistic screening program. The pooled outcomes of CCE-2 for polyps at least 6 mm / 10 mm were (CI = confidence interval): sensitivity: 88% (95% CI: 0.84-0.91) / 88% (95% CI: 0.82-0.93), specificity: 94% (95% CI: 0.92-0.95) / 95.5% (95% CI: 0.94-0.97); positive likelihood ratio: 11.86 (95% CI: 5.53-25.46) / 23.07 (95% CI: 6.163-86.36); negative likelihood ratio: 0.14 (95% CI: 0.1-0.21) / 0.14 (95% CI: 0.09-0.21). The area under the summary receiver operating characteristic curve for polyps at least 6 and 10 mm was 96.3% and 96.7%, respectively. The only cancer missed by complete CCE-2 was shown at multiple frames in the unblinded review. In total, 125 (7.8%) patients presented mild adverse events mostly related to bowel preparation. CONCLUSION: CCE-2 is demonstrated to be an effective and safe alternative method for colorectal cancer screening. Diagnostic performance of CCE-2 for polyps of at least 6 and 10 mm was similar. Completion rates still need to be improved.

How a managed service for colon capsule endoscopy works in an overstretched healthcare system.

Lower gastrointestinal diagnostics have been facing significant capacity constraints, which the COVID-19 pandemic has exacerbated due to significant reductions in endoscopy procedures. Colon Capsule Endoscopy (CCE) provides a safe, viable solution to offset ongoing demand and could be a valuable tool for the recovery of endoscopy services post-COVID. NHS Scotland has already begun a country-wide rollout of CCE as a managed service, and NHS England have committed to a pilot scheme of 11,000 capsules via hospital-based delivery. Here, we outline a proven method of CCE delivery that ensures the CCE and results are delivered in an efficient, clinically robust manner with high patient acceptability levels through a managed service. Delivering CCE without a managed service is likely to be slower, more costly, and less effective, limiting the many benefits of CCE as an addition to the standard diagnostic pathway for bowel cancer.

Colon Capsule Endoscopy in the Assessment of Mucosal Healing in Crohn's Disease.

BACKGROUND: Patients with Crohn's disease (CD) undergo frequent endoscopic procedures, with visualization of the gastrointestinal mucosa central to treatment decision-making. Subsequently, a noninvasive alternative to optical colonoscopy (OC) would be welcomed. One such technology is capsule endoscopy, including the PillCam COLON 2 (PCC2), though research validating its use in ileocolonic CD is limited. This study aims to compare PCC2 with ileocolonoscopy (OC) in assessing mucosal CD through use of a standardized scoring system. METHODS: At an Australian tertiary hospital, same-day PCC2 and ileocolonoscopy results of 47 CD patients, with known nonstricturing disease, were prospectively collected and analyzed for correlation and agreement. Deidentified recordings were reported by a single expert gastroenterologist. Mucosal disease was quantified using the Simple Endoscopic Score for Crohn's Disease (SES-CD). The SES-CD results of paired endoscopic modalities were compared in total per bowel segment and per SES-CD variable. RESULTS: Of 47 PCC2 recordings, 68% were complete, fully assessing terminal ileum to rectum, and OC was complete in 89%. Correlation (r) between total SES-CD scores was strongest in the terminal ileum (r = 0.77, P < .001), with the SES-CD variable of "ulcer detection" showing the strongest agreement. The PCC2 (vs OC) identified additional ulcers in the terminal ileum; ascending, transverse, and descending colon; and rectum; scores were 5 (1), 5 (3), 1 (1), 2 (1), and 2 (2), respectively. CONCLUSIONS: The PCC2 shows promise in assessing ileocolonic mucosa, especially in proximal bowel segments, with greater reach of visualization in the small bowel. Given the resource and safety considerations raised by the Coronavirus disease 2019 pandemic, capsule endoscopy has particular significance.This article aims to contribute to the limited body of research surrounding the validity of capsule endoscopy technology in assessing ileocolonic mucosa in Crohn's Disease patients. In doing so, an alternative option for patients enduring frequent endoscopies is given potential.

Impact of COVID-19 pandemic on fecal immunochemical test screening uptake and compliance to diagnostic colonoscopy.

BACKGROUND AND AIM: During this COVID-19 pandemic, Taiwan is one of the few countries where fecal immunochemical test and endoscopic activity for colorectal cancer screening keeps ongoing. We aimed to investigate how screening uptake and colonoscopy rate were affected in one of the biggest screening hubs in Northern Taiwan. METHODS: We conducted a prospective observational study tracing and analyzing the screening uptake and the trend of compliance to diagnostic colonoscopy in fecal immunochemical test-positive subjects in the National Taiwan University Hospital screening hub since the outbreak of COVID-19 and compared it with that of the corresponding periods in the past 3 years. Cancellation and rescheduling rates of colonoscopy and related reasons were also explored. RESULTS: Screening uptake during December 2019 to April 2020 was 88.8%, which was significantly lower than that in the corresponding period of the past 3 years (91.2-92.7%, P for trend < 0.0001). Colonoscopy rate in this period was 66.1%, which was also significantly lower than that in the past 3 years (70.2-77.5%, P for trend = 0.017). Rescheduling or cancellation rate was up to 10.9%, which was significantly higher than that in the past 3 years (P for trend = 0.023), and half of them was due to the fear of being infected. CONCLUSION: Fecal immunochemical test screening was significantly affected by COVID-19 pandemic. In order to resume the practice in COVID-19 era, screening organizers should consider various approaches to secure timely diagnosis of colorectal cancer.

Prioritisation by FIT to mitigate the impact of delays in the 2-week wait colorectal cancer referral pathway during the COVID-19 pandemic: a UK modelling study.

OBJECTIVE: To evaluate the impact of faecal immunochemical testing (FIT) prioritisation to mitigate the impact of delays in the colorectal cancer (CRC) urgent diagnostic (2-week-wait (2WW)) pathway consequent from the COVID-19 pandemic. DESIGN: We modelled the reduction in CRC survival and life years lost resultant from per-patient delays of 2-6 months in the 2WW pathway. We stratified by age group, individual-level benefit in CRC survival versus age-specific nosocomial COVID-19-related fatality per referred patient undergoing colonoscopy. We modelled mitigation strategies using thresholds of FIT triage of 2, 10 and 150 µg Hb/g to prioritise 2WW referrals for colonoscopy. To construct the underlying models, we employed 10-year net CRC survival for England 2008-2017, 2WW pathway CRC case and referral volumes and per-day-delay HRs generated from observational studies of diagnosis-to-treatment interval. RESULTS: Delay of 2/4/6 months across all 11 266 patients with CRC diagnosed per typical year via the 2WW pathway were estimated to result in 653/1419/2250 attributable deaths and loss of 9214/20 315/32 799 life years. Risk-benefit from urgent investigatory referral is particularly sensitive to nosocomial COVID-19 rates for patients aged >60. Prioritisation out of delay for the 18% of symptomatic referrals with FIT >10 µg Hb/g would avoid 89% of these deaths attributable to presentational/diagnostic delay while reducing immediate requirement for colonoscopy by >80%. CONCLUSIONS: Delays in the pathway to CRC diagnosis and treatment have potential to cause significant mortality and loss of life years. FIT triage of symptomatic patients in primary care could streamline access to colonoscopy, reduce delays for true-positive CRC cases and reduce nosocomial COVID-19 mortality in older true-negative 2WW referrals. However, this strategy offers benefit only in short-term rationalisation of limited endoscopy services: the appreciable false-negative rate of FIT in symptomatic patients means most colonoscopies will still be required.

Adoption of Multi-society Guidelines Facilitates Value-Based Reduction in Screening and Surveillance Colonoscopy Volume During COVID-19 Pandemic.

BACKGROUND: COVID-19 has caused a backlog of endoscopic procedures; colonoscopy must now be prioritized to those who would benefit most. We determined the proportion of screening and surveillance colonoscopies appropriate for rescheduling to a future year through strict adoption of US Multi-Society Task Force (USMSTF) guidelines. METHODS: We conducted a single-center observational study of patients scheduled for "open-access colonoscopy"-ordered by a primary care provider without being seen in gastroenterology clinic-over a 6-week period during the COVID-19 pandemic. Each chart was reviewed to appropriately assign a surveillance year per USMSTF guidelines including demographics, colonoscopy history and family history. When guidelines recommended a range of colonoscopy intervals, both a "conservative" and "liberal" guideline adherence were assessed. RESULTS: We delayed 769 "open-access" screening or surveillance colonoscopies due to COVID-19. Between 14.8% (conservative) and 20.7% (liberal), colonoscopies were appropriate for rescheduling to a future year. Conversely, 415 (54.0%) patients were overdue for colonoscopy. Family history of CRC was associated with being scheduled too early for both screening (OR 3.9; CI 1.9-8.2) and surveillance colonoscopy (OR 2.6, CI 1.0-6.5). The most common reasons a colonoscopy was inappropriately scheduled this year were failure to use new surveillance colonoscopy intervals (28.9%), incorrectly applied family history guidelines (27.2%) and recommending early surveillance colonoscopy after recent normal colonoscopy (19.3%). CONCLUSION: Up to one-fifth of patients scheduled for "open-access" colonoscopy can be rescheduled into a future year based on USMSTF guidelines. Rigorously applying guidelines could judiciously allocate colonoscopy resources as we recover from the COVID-19 pandemic.