Canadian colorectal cancer screening programs: How do they measure up using the International Agency for Research on Cancer criteria for organized screening?

Background: Canada has one of the highest incidences of colorectal cancer (CRC) worldwide. CRC screening improves CRC outcomes and is cost-effective. This study compares Canadian CRC screening programs using essential elements of an organized screening program outlined by the International Agency for Research on Cancer (IARC). Methods: We collaborated with the Cancer Screening in 5 continents (CanScreen5) program, an initiative of IARC. Standardized data collection forms were sent to representatives of provincial and territorial CRC screening programs. Twenty-five questions were selected to reflect IARC's essential elements of an organized screening program. We performed a qualitative analysis of Canada's CRC screening programs and compared programs within Canada and internationally. Results: CRC screening programs exist in 10 provinces and 2 territories. None of the programs in Canada met all the essential criteria of an organized screening program outlined by IARC. Three programs do not send invitations to participate in screening. Among those that do, 4 programs do not include a stool test kit in the invitations. While all provinces met the essential elements for leadership, governance, finance, and access to essential services, there was more heterogeneity in the domains of service delivery as well as information systems and quality assurance. Conclusions: There is considerable heterogeneity in the design of CRC screening programs in Canada and worldwide. Programs should strive to meet all the essential IARC criteria for organized screening if local resources allow, such as issuing invitations and implementing systems to track and compare outcomes to maximize screening program quality, effectiveness, and impact.

Incidence, Predictors, and Outcomes of Clinically Significant Post-ERCP Bleeding: a Contemporary Multi-center Study.

BACKGROUND AIMS: Clinically significant post-endoscopic retrograde cholangiopancreatography (ERCP) bleeding (CSPEB) is common. Contemporary estimates of risk are lacking. We aimed to identify risk factors for and outcomes following CSPEB. METHODS: We analyzed multi-center prospective ERCP data between 2018-2023 with 30-day follow-up. The primary outcome was CSPEB, defined as hematemesis, melena, or hematochezia resulting in: hemoglobin drop ≥20 g/L or transfusion and/or endoscopy to evaluate suspected bleeding, and/or unplanned healthcare visitation and/or prolongation of existing admission. Firth logistic regression was employed. P-values <0.05 were significant, with odds ratios (ORs) and 95% confidence intervals reported. RESULTS: CSPEB occurred following 129 (1.5%) of 8,517 ERCPs (mean onset 3.2 days), with 110 of 4,849 events (2.3%) occurring following higher-risk interventions (sphincterotomy, sphincteroplasty, pre-cut sphincterotomy, and/or needle-knife access). CSPEB patients required endoscopy and transfusion in 86.0% and 53.5% of cases, respectively, with three cases (2.3%) being fatal. P2Y12 inhibitors were held for a median of 4 days (IQR 4) prior to higher-risk ERCP. Following higher-risk interventions, P2Y12 inhibitors (OR 3.33, 1.26-7.74), warfarin (OR 8.54, 3.32-19.81), dabigatran (OR 13.40, 2.06-59.96), rivaroxaban (OR 7.42, 3.43-15.24) and apixaban (OR 4.16, 1.99-8.20) were associated with CSPEB. Significant intraprocedural bleeding post sphincterotomy (OR 2.32, 1.06-4.60), but not post sphincteroplasty, was also associated. Concomitant cardiorespiratory events occurred more frequently within 30 days following CSPEB (OR 12.71, 4.75-32.54). CONCLUSIONS: Risks of antiplatelet-related CSPEB may be underestimated by endoscopists based on observations of suboptimal holding before higher-risk ERCP. Appropriate periprocedural antithrombotic management is essential and could represent novel quality initiative targets.

The use of cap-mounted clips as a primary hemostatic modality in nonvariceal upper gastrointestinal bleeding: A systematic review and meta-analysis of randomized trials.

BACKGROUND: Cap-mounted-clips, especially Over-The-Scope-Clip (OTSC™), are recommended for recurrent nonvariceal upper gastrointestinal bleeding (NVUGIB). There has been recent interest in their use as an initial hemostatic modality. We performed a systematic review of randomized controlled trials (RCTs) assessing cap-mounted clips' efficacy as a primary hemostatic modality in NVUGIB. METHODS: A literature search of MEDLINE, EMBASE, and ISI Web of Science databases up to April 2024 identified RCTs comparing cap-mounted clips to standard endoscopic therapy (SET) as a primary hemostatic modality in NVUGIB. The primary endpoint was the composite outcome of further bleeding (persistent or recurrent) at 30 days. Secondary outcomes included persistent bleeding at index endoscopy and 30-day rebleeding, individually. Other pertinent outcomes were also recorded. A meta-analysis was performed to determine pooled risk ratios (RRs), comparing cap-mounted clip to SET. Out of 516 citations, five RCTs (n = 555), all assessing OTSC™, were included. RESULTS: The composite outcome of further bleeding was lower with cap-mounted clip versus SET (RR = 0.33 [95% confidence interval {CI}: 0.20-0.54]). There was no difference in persistent bleeding at initial endoscopy (RR = 0.30 [95% CI: 0.07-1.30]), but 30-day rebleeding was lower with cap-mounted clip (RR = 0.38 [95% CI: 0.21-0.70]). There were no differences in other outcomes. Grading of the evidence ranged from very low to moderate, mainly due to risk of bias and imprecision. CONCLUSIONS: Cap-mounted clips may be an efficacious primary hemostatic modality, associated with a lower further bleeding at 30 days compared to SET in NVUGIB. However, due to limitations in existing evidence, further research must better characterize an optimal subgroup of patients benefiting most from this approach before adopting its routine use.

Peptic ulcer disease.

Annual prevalence estimates of peptic ulcer disease range between 0·12% and 1·5%. Peptic ulcer disease is usually attributable to Helicobacter pylori infection, intake of some medications (such as aspirin and non-steroidal anti-inflammatory medications), or being critically ill (stress-related), or it can be idiopathic. The clinical presentation is usually uncomplicated, with peptic ulcer disease management based on eradicating H pylori if present, the use of acid-suppressing medications-most often proton pump inhibitors (PPIs)-or addressing complications, such as with early endoscopy and high-dose PPIs for peptic ulcer bleeding. Special considerations apply to patients on antiplatelet and antithrombotic agents. H pylori treatment has evolved, with the choice of regimen dictated by local antibiotic resistance patterns. Indications for primary and secondary prophylaxis vary across societies; most suggest PPIs for patients at highest risk of developing a peptic ulcer, its complications, or its recurrence. Additional research areas include the use of potassium-competitive acid blockers and H pylori vaccination; the optimal approach for patients at risk of stress ulcer bleeding requires more robust determinations of optimal patient selection and treatment selection, if any. Appropriate continuation of PPI use outweighs most possible side-effects if given for approved indications, while de-prescribing should be trialled when a definitive indication is no longer present.

Periprocedural management of patients on a direct oral anticoagulant undergoing elective gastrointestinal endoscopy.

This narrative review summarizes the current body of literature regarding periprocedural management of direct oral anticoagulant (DOAC)-treated patients undergoing digestive endoscopy since the publication of the 2022 American College of Gastroenterology - Canadian Association of Gastroenterology guidelines. We provide a detailed analysis of the thromboembolic risk, endoscopic procedure-specific bleeding risks, contemporary intraprocedural techniques to reduce the bleeding risk, and a summary of periprocedural DOAC guidelines developed by major gastrointestinal societies, including recommendations on procedure risk stratification. Despite data heterogeneity, the overall trend of the current literature supports the contemporary practice of a minimal DOAC interruption without the need for heparin bridging.

Previously undiagnosed Morgagni hernia with bowel perforation detected during repeat screening colonoscopy: A case report.

BACKGROUND: Morgagni hernia (MH) is a form of congenital diaphragmatic hernia (CDH) characterized by an incomplete formation of diaphragm, resulting in the protrusion of abdominal organs into the thoracic cavity. The estimated incidence of CDH is between 1 in 2000 and 1 in 5000 live births, although the true incidence is unknown. MH typically presents in childhood and can be diagnosed either prenatally or postnatally. However, it can also be asymptomatic and carry the risk of developing into a life-threatening condition in adulthood. CASE SUMMARY: A 76-year-old female with no history of prior abdominal surgeries presented for an elective colonoscopy for polyp surveillance. During the procedure, when approaching the hepatic flexure, the scope could not be advanced further despite multiple attempts. The patient experienced mild abdominal discomfort, leading to the abortion of the procedure. While in the recovery area, she developed increasing abdominal pains and hypotension. Urgent abdominal imaging revealed herniation of the proximal transverse colon through a MH into the chest with evidence of perforation. The patient underwent laparoscopic urgent colonic resection and primary hernia repair and was discharged uneventfully 2 d later. CONCLUSION: A MH is a rare condition in adults that can present as a life-threatening complication of colonoscopy, even in patients with a history of uneventful colonoscopies. This case highlights the importance of considering congenital and internal hernias when faced with sudden and unexplained difficulties during colonoscopy. If there is a suspicion of MH, the endoscopist should halt the procedure and immediately obtain abdominal imaging to confirm the diagnosis.

Effect of fecal immunochemical test cut-off levels on adenoma detection rate: a systematic review and meta-analysis.

BACKGROUND: Adenoma detection rate (ADR) is higher after a positive fecal immunochemical test (FIT) compared to direct screening colonoscopy. OBJECTIVE: This meta-analysis evaluated how ADR, the rates of advanced adenoma detection (AADR), colorectal cancer detection (CDR), and sessile serrated lesion detection (SSLDR) are affected by different FIT positivity thresholds. METHODS: We searched MEDLINE, EMBASE, CINAHL, and EBM Reviews databases for studies reporting ADR, AADR, CDR, and SSLDR according to different FIT cut-off values in asymptomatic average-risk individuals aged 50-74 years old. Data were stratified according to sex, age, time to colonoscopy, publication year, continent, and FIT kit type. Study quality, heterogeneity, and publication bias were assessed. RESULTS: Overall, 4280 articles were retrieved and fifty-eight studies were included (277,661 FIT-positive colonoscopies; mean cecal intubation 96.3%; mean age 60.8 years; male 52.1%). Mean ADR was 56.1% (95% CI 53.4 - 58.7%), while mean AADR, CDR, and SSLDR were 27.2% (95% CI 24.4 - 30.1%), 5.3% (95% CI 4.7 - 6.0%), and 3.0% (95% CI 1.7 - 4.6%), respectively. For each 20 µg Hb/g increase in FIT cut-off level, ADR increased by 1.54% (95% CI 0.52 - 2.56%, p < 0.01), AADR by 3.90% (95% CI 2.76 - 5.05%, p < 0.01) and CDR by 1.46% (95% CI 0.66 - 2.24%, p < 0.01). Many detection rates were greater amongst males and Europeans. CONCLUSIONS: ADRs in FIT-positive colonoscopies are influenced by the adopted FIT positivity threshold, and identified targets, importantly, proved to be higher than most current societal recommendations.

Expert endoscopist assessment of colorectal polyp size using virtual scale endoscopy, visual or snare-based estimation: a prospective video-based study.

BACKGROUND AND AIMS: Accurate polyp size estimation during colonoscopy has an impact on clinical decision-making. A laser-based virtual scale endoscope (VSE) is available to allow measuring polyp size using a virtual adaptive scale. This study evaluates video-based polyp size measurement accuracy among expert endoscopists using either VSE or visual assessment (VA) with either snare as reference size or without any reference size information. METHODS: A prospective, video-based study was conducted with 10 expert endoscopists. Video sequences from 90 polyps with known reference size (fresh specimen measured using calipers) were distributed on three different slide sets so that each slide set showed the same polyp only once with either VSE, VA or snare-based information. A slide set was randomly assigned to each endoscopist. Endoscopists were asked to provide size estimation based on video review. RESULTS: Relative accuracies for VSE, VA, and snare-based estimation were 75.1% (95% CI [71.6-78.5]), 65.0% (95% CI [59.5-70.4]) and 62.0% (95% CI [54.8-69.0]), respectively. VSE yielded significantly higher relative accuracy compared to VA (p = 0.002) and to snare (p = 0.001). A significantly lower percentage of polyps 1-5 mm were misclassified as >5 mm using VSE versus VA and snare (6.52% vs. 19.6% and 17.5%, p = 0.004) and a significantly lower percentage of polyps >5 mm were misclassified as 1-5 mm using VSE versus VA and snare (11.4% vs. 31.9% and 14.9%, p = 0.038). CONCLUSIONS: Endoscopists estimate polyp size with the highest accuracy when virtual adaptive scale information is displayed. Using a snare to assist sizing did not improve measurement accuracy compared to displaying visual information alone.

Assessment, Resuscitation and Medical Management of Variceal and Nonvariceal Gastrointestinal Bleeding.

Upper gastrointestinal bleeding (UGIB) continues to be an important cause for emergency room visits and carries significant morbidity and mortality. Early resuscitative measures form the basis of the management of patients presenting with UGIB and can improve the outcomes of such patients including lowering mortality. In this review, using an evidence-based approach, we discuss the initial assessment and resuscitation of patients presenting with UGIB including identifying clues from history and physical examination to confirm UGIB, preendoscopic risk assessment tools, the role of early fluid resuscitation, utilization of blood products, use of pharmacologic interventions, and the optimal timing of endoscopy.

Primary and Specialty Care Trainees' Perceptions About Proton Pump Inhibitor Use.

OBJECTIVE: Proton pump inhibitors (PPIs) are widely prescribed with proven efficacy in many indications, yet longstanding controversy about potential adverse events persists. We aimed to acquire knowledge about perceptions of outpatient PPI long-term prescribing (≥8 wk) among primary and specialty care trainees at 2 Canadian Universities. METHODS: Family medicine, internal medicine, and gastroenterology trainees completed a web-based survey that included 20 clinical scenarios assessing trainee knowledge about PPI efficacy. Contextual PPI prescribing decisions were also elicited, balancing possible PPI indications versus side effects. Management strategies were compared between junior and senior trainees, as well as across training programs. RESULTS: Over a 4-month period,163 trainees (age <26 y: 12%; age 26 to 45: 88%; 59% females) participated in the survey (family medicine: 51%, internal medicine: 44%, and gastroenterology: 5%); 83% were considered junior residents. Only 42% had received formal education on prescribing PPI long-term. Overall, 93% believed they would benefit from such teaching, with 98% stating they would follow related guidelines. No between-group differences were noted in knowledge of appropriate PPI indications nor possible side effects when comparing juniors to seniors, or among different specialties. Across different management scenarios, inappropriate PPI discontinuation was chosen by 14.3% to 67.2%, whereas inappropriate PPI continuation was reported in up to 57%. Trainee seniority and specialty did not differ in appropriate deprescribing rates. CONCLUSIONS: Training level and primary versus specialty care settings are associated with frequent inappropriate PPI prescribing and deprescribing. These findings highlight the need for and may inform future educational programs on PPI usage.

Autonomous Artificial Intelligence vs Artificial Intelligence-Assisted Human Optical Diagnosis of Colorectal Polyps: A Randomized Controlled Trial.

BACKGROUND & AIMS: Artificial intelligence (AI)-based optical diagnosis systems (CADx) have been developed to allow pathology prediction of colorectal polyps during colonoscopies. However, CADx systems have not yet been validated for autonomous performance. Therefore, we conducted a trial comparing autonomous AI to AI-assisted human (AI-H) optical diagnosis. METHODS: We performed a randomized noninferiority trial of patients undergoing elective colonoscopies at 1 academic institution. Patients were randomized into (1) autonomous AI-based CADx optical diagnosis of diminutive polyps without human input or (2) diagnosis by endoscopists who performed optical diagnosis of diminutive polyps after seeing the real-time CADx diagnosis. The primary outcome was accuracy in optical diagnosis in both arms using pathology as the gold standard. Secondary outcomes included agreement with pathology for surveillance intervals. RESULTS: A total of 467 patients were randomized (238 patients/158 polyps in the autonomous AI group and 229 patients/179 polyps in the AI-H group). Accuracy for optical diagnosis was 77.2% (95% confidence interval [CI], 69.7-84.7) in the autonomous AI group and 72.1% (95% CI, 65.5-78.6) in the AI-H group (P = .86). For high-confidence diagnoses, accuracy for optical diagnosis was 77.2% (95% CI, 69.7-84.7) in the autonomous AI group and 75.5% (95% CI, 67.9-82.0) in the AI-H group. Autonomous AI had statistically significantly higher agreement with pathology-based surveillance intervals compared to AI-H (91.5% [95% CI, 86.9-96.1] vs 82.1% [95% CI, 76.5-87.7]; P = .016). CONCLUSIONS: Autonomous AI-based optical diagnosis exhibits noninferior accuracy to endoscopist-based diagnosis. Both autonomous AI and AI-H exhibited relatively low accuracy for optical diagnosis; however, autonomous AI achieved higher agreement with pathology-based surveillance intervals. (ClinicalTrials.gov, Number NCT05236790).

Indomethacin with or without prophylactic pancreatic stent placement to prevent pancreatitis after ERCP: a randomised non-inferiority trial.

BACKGROUND: The combination of rectally administered indomethacin and placement of a prophylactic pancreatic stent is recommended to prevent pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP) in high-risk patients. Preliminary evidence suggests that the use of indomethacin might eliminate or substantially reduce the need for stent placement, a technically complex, costly, and potentially harmful intervention. METHODS: In this randomised, non-inferiority trial conducted at 20 referral centres in the USA and Canada, patients (aged ≥18 years) at high risk for post-ERCP pancreatitis were randomly assigned (1:1) to receive rectal indomethacin alone or the combination of indomethacin plus a prophylactic pancreatic stent. Patients, treating clinicians, and outcomes assessors were masked to study group assignment. The primary outcome was post-ERCP pancreatitis. To declare non-inferiority, the upper bound of the two-sided 95% CI for the difference in post-ERCP pancreatitis (indomethacin alone minus indomethacin plus stent) would have to be less than 5% (non-inferiority margin) in both the intention-to-treat and per-protocol populations. This trial is registered with ClinicalTrials.gov (NCT02476279), and is complete. FINDINGS: Between Sept 17, 2015, and Jan 25, 2023, a total of 1950 patients were randomly assigned. Post-ERCP pancreatitis occurred in 145 (14·9%) of 975 patients in the indomethacin alone group and in 110 (11·3%) of 975 in the indomethacin plus stent group (risk difference 3·6%; 95% CI 0·6-6·6; p=0·18 for non-inferiority). A post-hoc intention-to-treat analysis of the risk difference between groups showed that indomethacin alone was inferior to the combination of indomethacin plus prophylactic stent (p=0·011). The relative benefit of stent placement was generally consistent across study subgroups but appeared more prominent among patients at highest risk for pancreatitis. Safety outcomes (serious adverse events, intensive care unit admission, and hospital length of stay) did not differ between groups. INTERPRETATION: For preventing post-ERCP pancreatitis in high-risk patients, a strategy of indomethacin alone was not as effective as a strategy of indomethacin plus prophylactic pancreatic stent placement. These results support prophylactic pancreatic stent placement in addition to rectal indomethacin administration in high-risk patients, in accordance with clinical practice guidelines. FUNDING: US National Institutes of Health.

Review article: Advances in the management of lower gastrointestinal bleeding.

BACKGROUND: Lower gastrointestinal bleeding (LGIB) is a common emergency with substantial associated morbidity and mortality. Elective colonoscopy plays an essential role in management, with an even more important role for radiology in the acute setting. Recent advances in the management of patients with LGIB warrant review as the management has recently evolved. AIMS: To provide a comprehensive and updated overview of advances in the approach to patients with LGIB METHODS: We performed a comprehensive literature search to examine the current data for this narrative review supplemented by expert opinion. RESULTS: The incidence of LGIB is increasing worldwide, partly related to an ageing population and the increasing use of antithrombotics. Diverticulosis continues to be the most common aetiology of LGIB. Pre-endoscopic risk stratification tools, especially the Oakland score, can aid appropriate patient triage. Adequate resuscitation continues to form the basis of management, while appropriate management of antithrombotics is crucial to balance the risk of worsening bleeding against increased cardiovascular risk. Radiological imaging plays an essential role in the diagnosis and treatment of acute LGIB, especially among unstable patients. Colonoscopy remains the gold-standard test for the elective management of stable patients. CONCLUSIONS: The management of LGIB has evolved significantly in recent years, with a shift towards radiological interventions for unstable patients while reserving elective colonoscopy for stable patients. A multidisciplinary approach is essential to optimise the outcomes of patients with LGIB.

Measuring the observer (Hawthorne) effect on adenoma detection rates.

Background and study aims An independent observer can improve procedural quality. We evaluated the impact of the observer (Hawthorne effect) on important quality metrics during colonoscopies. Patients and Methods In a single-center comparative study, consecutive patients undergoing routine screening or diagnostic colonoscopy were prospectively enrolled. In the index group, all procedural steps and quality metrics were observed and documented, and the procedure was video recorded by an independent research assistant. In the reference group, colonoscopies were performed without independent observation. Colonoscopy quality metrics such as polyp, adenoma, serrated lesions, and advanced adenoma detection rates (PDR, ADR, SLDR, AADR) were compared. The probabilities of increased quality metrics were evaluated through regression analyses weighted by the inversed probability of observation during the procedure. Results We included 327 index individuals and 360 referents in the final analyses. The index group had significantly higher PDRs (62.4% vs. 53.1%, P =0.02) and ADRs (39.4% vs. 28.3%, P =0.002) compared with the reference group. The SLDR and AADR were not significantly increased. After adjusting for potential confounders, the ADR and SLDR were 50% (relative risk [RR] 1.51; 95%, CI 1.05-2.17) and more than twofold (RR 2.17; 95%, CI 1.05-4.47) more likely to be higher in the index group than in the reference group. Conclusions The presence of an independent observer documenting colonoscopy quality metrics and video recording the colonoscopy resulted in a significant increase in ADR and other quality metrics. The Hawthorne effect should be considered an alternative strategy to advanced devices to improve colonoscopy quality in practice.

Endoscopic Ultrasound-Guided Biliary Drainage of First Intent With a Lumen-Apposing Metal Stent vs Endoscopic Retrograde Cholangiopancreatography in Malignant Distal Biliary Obstruction: A Multicenter Randomized Controlled Study (ELEMENT Trial).

BACKGROUND & AIMS: Endoscopic ultrasound-guided choledochoduodenostomy with a lumen-apposing metal stent (EUS-CDS) is a promising modality for management of malignant distal biliary obstruction (MDBO) with potential for better stent patency. We compared its outcomes with endoscopic retrograde cholangiopancreatography with metal stenting (ERCP-M). METHODS: In this multicenter randomized controlled trial, we recruited patients with MDBO secondary to borderline resectable, locally advanced, or unresectable peri-ampullary cancers across 10 Canadian institutions and 1 French institution. This was a superiority trial with a noninferiority assessment of technical success. Patients were randomized to EUS-CDS or ERCP-M. The primary end point was the rate of stent dysfunction at 1 year, considering competing risks of death, clinical failure, and surgical resection. Analyses were performed according to intention-to-treat principles. RESULTS: From February 2019 to February 2022, 144 patients were recruited; 73 were randomized to EUS-CDS and 71 were randomized to ERCP-M. The mean (SD) procedure time was 14.0 (11.4) minutes for EUS-CDS and 23.1 (15.6) minutes for ERCP-M (P < .01); 40% of the former was performed without fluoroscopy. Technical success was achieved in 90.4% (95% CI, 81.5% to 95.3%) of EUS-CDS and 83.1% (95% CI, 72.7% to 90.1%) of ERCP-M with a risk difference of 7.3% (95% CI, -4.0% to 18.8%) indicating noninferiority. Stent dysfunction occurred in 9.6% vs 9.9% of EUS-CDS and ERCP-M cases, respectively (P = .96). No differences in adverse events, pancreaticoduodenectomy and oncologic outcomes, or quality of life were noted. CONCLUSIONS: Although not superior in stent function, EUS-CDS is an efficient and safe alternative to ERCP-M in patients with MDBO. These findings provide evidence for greater adoption of EUS-CDS in clinical practice as a complementary and exchangeable first-line modality to ERCP in patients with MDBO. CLINICALTRIALS: gov, Number: NCT03870386.

Pre-Endoscopic Scores Predicting Low-Risk Patients with Upper Gastrointestinal Bleeding: A Systematic Review and Meta-Analysis.

BACKGROUND: Several risk scores have attempted to risk stratify patients with acute upper gastrointestinal bleeding (UGIB) who are at a lower risk of requiring hospital-based interventions or negative outcomes including death. This systematic review and meta-analysis aimed to compare predictive abilities of pre-endoscopic scores in prognosticating the absence of adverse events in patients with UGIB. METHODS: We searched MEDLINE, EMBASE, Central, and ISI Web of knowledge from inception to February 2023. All fully published studies assessing a pre-endoscopic score in patients with UGIB were included. The primary outcome was a composite score for the need of a hospital-based intervention (endoscopic therapy, surgery, angiography, or blood transfusion). Secondary outcomes included: mortality, rebleeding, or the individual endpoints of the composite outcome. Both proportional and comparative analyses were performed. RESULTS: Thirty-eight studies were included from 2153 citations, (n = 36,215 patients). Few patients with a low Glasgow-Blatchford score (GBS) cutoff (0, ≤1 and ≤2) required hospital-based interventions (0.02 (0.01, 0.05), 0.04 (0.02, 0.09) and 0.03 (0.02, 0.07), respectively). The proportions of patients with clinical Rockall (CRS = 0) and ABC (≤3) scores requiring hospital-based intervention were 0.19 (0.15, 0.24) and 0.69 (0.62, 0.75), respectively. GBS (cutoffs 0, ≤1 and ≤2), CRS (cutoffs 0, ≤1 and ≤2), AIMS65 (cutoffs 0 and ≤1) and ABC (cutoffs ≤1 and ≤3) scores all were associated with few patients (0.01-0.04) dying. The proportion of patients suffering other secondary outcomes varied between scoring systems but, in general, was lowest for the GBS. GBS (using cutoffs 0, ≤1 and ≤2) showed excellent discriminative ability in predicting the need for hospital-based interventions (OR 0.02, (0.00, 0.16), 0.00 (0.00, 0.02) and 0.01 (0.00, 0.01), respectively). A CRS cutoff of 0 was less discriminative. For the other secondary outcomes, discriminative abilities varied between scores but, in general, the GBS (using cutoffs up to 2) was clinically useful for most outcomes. CONCLUSIONS: A GBS cut-off of one or less prognosticated low-risk patients the best. Expanding the GBS cut-off to 2 maintains prognostic accuracy while allowing more patients to be managed safely as outpatients. The evidence is limited by the number, homogeneity, quality, and generalizability of available data and subjectivity of deciding on clinical impact. Additional, comparative and, ideally, interventional studies are needed.