Variation in Adenoma Detection Rate and the Lifetime Benefits and Cost of Colorectal Cancer Screening: A Microsimulation Model

Projected Colorectal Cancer Incidence and Mortality Based on Observed Adherence to Colonoscopy and Sequential Stool-Based Screening

INTRODUCTION

Modeling supporting recommendations for colonoscopy and stool-based colorectal cancer (CRC) screening tests assumes 100% sequential participant adherence. The impact of observed adherence on the long-term effectiveness of screening is unknown. We evaluated the effectiveness of a program of screening colonoscopy every 10 years vs annual high-sensitivity guaiac-based fecal occult blood testing (HSgFOBT) using observed sequential adherence data.

METHODS

The MIcrosimulation SCreening ANalysis (MISCAN) model used observed sequential screening adherence, HSgFOBT positivity, and diagnostic colonoscopy adherence in HSgFOBT-positive individuals from the National Colonoscopy Study (single-screening colonoscopy vs ≥4 HSgFOBT sequential rounds). We compared CRC incidence and mortality over 15 years with no screening or 10 yearly screening colonoscopy vs annual HSgFOBT with 100% and differential observed adherence from the trial.

RESULTS

Without screening, simulated incidence and mortality over 15 years were 20.9 (95% probability interval 15.8-26.9) and 6.9 (5.0-9.2) per 1,000 participants, respectively. In the case of 100% adherence, only screening colonoscopy was predicted to result in lower incidence; however, both tests lowered simulated mortality to a similar level (2.1 [1.6-2.9] for screening colonoscopy and 2.5 [1.8-3.4] for HSgFOBT). Observed adherence for screening colonoscopy (83.6%) was higher than observed sequential HSgFOBT adherence (73.1% first round; 49.1% by round 4), resulting in lower simulated incidence and mortality for screening colonoscopy (14.4 [10.8-18.5] and 2.9 [2.1-3.9], respectively) than HSgFOBT (20.8 [15.8-28.1] and 3.9 [2.9-5.4], respectively), despite a 91% adherence to diagnostic colonoscopy with FOBT positivity. The relative risk of CRC mortality for screening colonoscopy vs HSgFOBT was 0.75 (95% probability interval 0.68-0.80). Findings were similar in sensitivity analyses with alternative assumptions for repeat colonoscopy, test performance, risk, age, and projection horizon.

DISCUSSION

Where sequential adherence to stool-based screening is suboptimal and colonoscopy is accessible and acceptable-as observed in the national colonoscopy study, microsimulation, comparative effectiveness, screening recommendations.

Differential impact of test performance characteristics on burden-to-benefit tradeoffs for blood-based colorectal cancer screening: A microsimulation analysis

OBJECTIVES

To inform the development and evaluation of new blood-based colorectal cancer (CRC) screening tests satisfying minimum United States (US) coverage criteria, we estimated the impact of the different test performance characteristics on long-term testing benefits and burdens.

METHODS

A novel CRC-Microsimulation of Adenoma Progression and Screening (CRC-MAPS) model was developed, validated, then used to assess different screening tests for CRC. We compared multiple, hypothetical blood-based CRC screening tests satisfying minimum coverage criteria of 74% CRC sensitivity and 90% specificity, to measure how changes in a test's CRC sensitivity, specificity, and adenoma sensitivity (sizes 1-5 mm, 6-9 mm, ≥10 mm) affect total number of colonoscopies (COL), CRC incidence reduction (IR), CRC mortality reduction (MR), and burden-to-benefit ratios (incremental COLs per percentage-point increase in IR or MR).

RESULTS

A blood test meeting minimum US coverage criteria for performance characteristics resulted in 1576 lifetime COLs per 1000 individuals, 46.7% IR and 59.2% MR compared to no screening. Tests with increased CRC sensitivity of 99% ( + 25%) vs. increased ≥10 mm adenoma sensitivity of 13.6% ( + 3.6%) both yielded the same MR, 62.7%. Test benefits improved the most with increases in all-size adenoma sensitivity, then size-specific adenoma sensitivities, then specificity and CRC sensitivity, while increases in specificity or ≥10 mm adenoma sensitivity resulted in the most favorable burden-to-benefit tradeoffs (ratios <11.5).

CONCLUSIONS

Burden-to-benefit ratios for blood-based CRC screening tests differ by performance characteristic, with the most favorable tradeoffs resulting from improvements in specificity and ≥10 mm adenoma sensitivity.

Impact of a scalable training program on the quality of colonoscopy performance and risk of postcolonoscopy colorectal cancer

BACKGROUND AND AIMS

Endoscopist adenoma detection rates (ADRs) vary widely and are associated with patients' risk of postcolonoscopy colorectal cancers (PCCRCs). However, few scalable physician-directed interventions demonstrably both improve ADR and reduce PCCRC risk.

METHODS

Among patients undergoing colonoscopy, we evaluated the influence of a scalable online training on individual-level ADRs and PCCRC risk. The intervention was a 30-minute, interactive, online training, developed using behavior change theory, to address factors that potentially impede detection of adenomas. Analyses included interrupted time series analyses for pretraining versus posttraining individual-physician ADR changes (adjusted for temporal trends) and Cox regression for associations between ADR changes and patients' PCCRC risk.

RESULTS

Across 21 endoscopy centers and all 86 eligible endoscopists, ADRs increased immediately by an absolute 3.13% (95% confidence interval [CI], 1.31-4.94) in the 3-month quarter after training compared with .58% per quarter (95% CI, .40-.77) and 0.33% per quarter (95% CI, .16-.49) in the 3-year pretraining and posttraining periods, respectively. Posttraining ADR increases were higher among endoscopists with pretraining ADRs below the median. Among 146,786 posttraining colonoscopies (all indications), each 1% absolute increase in screening ADR posttraining was associated with a 4% decrease in their patients' PCCRC risk (hazard ratio, .96; 95% CI, .93-.99). An ADR increase of ≥10% versus <1% was associated with a 55% reduced risk of PCCRC (hazard ratio, .45; 95% CI, .24-.82).

CONCLUSIONS

A scalable, online behavior change training intervention focused on modifiable factors was associated with significant and sustained improvements in ADR, particularly among endoscopists with lower ADRs. These ADR changes were associated with substantial reductions in their patients' risk of PCCRC.

Older Age at First Screening Colonoscopy is Associated With an Increased Risk of Colorectal Adenomas and Cancer

INTRODUCTION

The goal of colorectal cancer (CRC) screening is to detect precancerous polyps before cancer development or identification of cancer at an early stage. Guidelines have recommended screening colonoscopy to start at age 45. Our aim was to determine the impact of delays in performing the first screening colonoscopy on the risk of adenoma or CRC detection.

METHODS

We analyzed colonoscopy and histopathology data of average CRC risk patients who had their first screening colonoscopy between 2010 and 2017. Univariate and multivariable logistic regression was performed to determine the association between demographic variables and the risk of adenomas or CRC.

RESULTS

A total of 1155 average risk patients underwent their initial screening colonoscopy during the study period. Median age was 54 years (range of 45-87) and 58.2% were females. In multivariable analysis, older age at first screening colonoscopy was significantly associated with the detection of adenomatous polyps (odds ratio 1.05, 95% confidence interval 1.04-1.07, P <0.001) and CRC (odds ratio 1.11, 95% confidence interval 1.06-1.16, P <0.001). The association between age and risk of adenomatous polyps (F-test 35.43, P =0.0019) and CRC (F-test 36.94, P =0.0017) fit an exponential growth model. It was estimated that the detection rate doubled every 14.20 years and 4.75 years for adenomas and CRC, respectively.

CONCLUSION

We found that older age at the initial performance of a screening colonoscopy was associated with increased detection of adenomatous polyps and CRC. This work highlights the need for guideline adherence for the prevention of CRC development.

Evaluation of the quality of colonoscopies performed by Alberta North Zone surgeons, family physicians and internists: a quality improvement initiative

BACKGROUND

In Canada, endoscopy is primarily performed by gastroenterologists and surgeons, and some studies report that colonoscopies performed by nongastroenterologists have more complications and higher rates of future colorectal cancer. Our objective was to determine whether rural-based nongastroenterologist endoscopists are achieving quality benchmarks in colonoscopy.

METHODS

This quality improvement initiative prospectively evaluated 6 key performance indicators (KPIs) (cecal intubations, polyp detection [males and females; for first-time colonoscopies on patients aged ≥ 50 yr], bowel preparations, patient comfort and withdrawal times) on consecutive colonoscopies performed by participating Alberta North Zone endoscopists. The study period was June 2018 to March 2020. Overall and individual endoscopist's KPIs were compared with standard benchmarks. Additional performance indicators included mean number of polyps per colonoscopy and an exploration of study-defined sedation-related level of consciousness.

RESULTS

Data were collected on 6212 colonoscopies performed by 16 endoscopists (9 surgeons, 5 family physicians and 2 internists) in 6 hospitals. All 6 KPI benchmarks were achieved when results were pooled over all endoscopists in the study. Overall, cecal intubation occurred in 6006 of 6209 (96.7%, 95% confidence interval 94.5%-99.0%) cases. Polyp detection was 65.9% (592/898) and 49.8% (348/699) for male and female patients, respectively, aged 50 years or older. Variability in individual endoscopist results existed, especially for the mean number of polyps per 100 colonoscopies and sedation-related level of consciousness.

INTERPRETATION

Overall, Alberta North Zone endoscopists are performing high-quality colonoscopies, collectively achieving all 6 KPIs. To understand endoscopic performance and encourage individual and group reflection on endoscopic practices, Canadian endoscopists are encouraged to participate in similar colonoscopy quality initiative studies.

An Evaluation of Critical Factors for the Cost-Effectiveness of Real-Time Computer-Aided Detection: Sensitivity and Threshold Analyses Using a Microsimulation Model

BACKGROUND

The use of computer-aided detection (CAD) increases the adenoma detection rates (ADRs) during colorectal cancer (CRC) screening/surveillance. This study aimed to evaluate the requirements for CAD to be cost-effective and the impact of CAD on adenoma detection by endoscopists with different ADRs.

METHODS

We developed a semi-Markov microsimulation model to compare the effectiveness of traditional colonoscopy (mean ADR, 26%) to colonoscopy with CAD (mean ADR, 37%). CAD was modeled as having a $75 per-procedure cost. Extensive 1-way sensitivity and threshold analysis were performed to vary cost and ADR of CAD. Multiple scenarios evaluated the potential effect of CAD on endoscopists' ADRs. Outcome measures were reported in incremental cost-effectiveness ratios, with a willingness-to-pay threshold of $100,000/quality-adjusted life year.

RESULTS

When modeling CAD improved ADR for all endoscopists, the CAD cohort had 79 and 34 fewer lifetime CRC cases and deaths, respectively, per 10,000 persons. This scenario was dominant with a cost savings of $143 and incremental effectiveness of 0.01 quality-adjusted life years. Threshold analysis demonstrated that CAD would be cost-effective up to an additional cost of $579 per colonoscopy, or if it increases ADR from 26% to at least 30%. CAD reduced CRC incidence and mortality when limited to improving ADRs for low-ADR endoscopists (ADR <25%), with 67 fewer CRC cases and 28 CRC deaths per 10,000 persons compared with traditional colonoscopy.

CONCLUSIONS

As CAD is implemented clinically, it needs to improve mean ADR from 26% to at least 30% or cost less than $579 per colonoscopy to be cost-effective when compared with traditional colonoscopy. Further studies are needed to understand the impact of CAD on community practice.

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.

Systematic analysis of the test design and performance of AI/ML-based medical devices approved for triage/detection/diagnosis in the USA and Japan

The development of computer-aided detection (CAD) using artificial intelligence (AI) and machine learning (ML) is rapidly evolving. Submission of AI/ML-based CAD devices for regulatory approval requires information about clinical trial design and performance criteria, but the requirements vary between countries. This study compares the requirements for AI/ML-based CAD devices approved by the US Food and Drug Administration (FDA) and the Pharmaceuticals and Medical Devices Agency (PMDA) in Japan. A list of 45 FDA-approved and 12 PMDA-approved AI/ML-based CAD devices was compiled. In the USA, devices classified as computer-aided simple triage were approved based on standalone software testing, whereas devices classified as computer-aided detection/diagnosis were approved based on reader study testing. In Japan, however, there was no clear distinction between evaluation methods according to the category. In the USA, a prospective randomized controlled trial was conducted for AI/ML-based CAD devices used for the detection of colorectal polyps, whereas in Japan, such devices were approved based on standalone software testing. This study indicated that the different viewpoints of AI/ML-based CAD in the two countries influenced the selection of different evaluation methods. This study’s findings may be useful for defining a unified global development and approval standard for AI/ML-based CAD.

Oral sulfate solution benefits polyp and adenoma detection during colonoscopy: Meta-analysis of randomized controlled trials

OBJECTIVES

Although oral sulfate solution (OSS) has been revealed to be not only safe and efficacious but also noninferior to polyethylene glycol with ascorbic acid (PEG + ASC), it is unclear whether OSS can ultimately increase the polyp detection rate (PDR) and adenoma detection rate (ADR). We performed this meta-analysis to estimate the effect of OSS on PDR and ADR during colonoscopy.

METHODS

We searched PubMed, EMBASE, and the Cochrane Library to identify relevant randomized controlled trials (RCTs) investigating the comparative effect of OSS versus PEG + ASC on the PDR and ADR during colonoscopy. Cecal intubation time (CIT), cecal intubation rate (CIR), and bowel preparation score were also evaluated. Review Manager (RevMan) version 5.3.0 was used to perform statistical analysis.

RESULTS

Eight RCTs involving 2059 patients fulfilled the selection criteria. Meta-analysis suggested that OSS significantly increased the PDR (47.34% vs. 40.14%, risk ratio [RR] 1.13, 95% confidence interval [CI] 1.03-1.24, P = 0.01) and ADR (44.60% vs. 38.14%, RR 1.17, 95% CI 1.03-1.33, P = 0.01) during colonoscopy. Subgroup analysis showed that the beneficial effects of OSS on PDR and ADR were consistent among patients with mean age >55 years and with body mass index <25 kg/m² receiving outpatient colonoscopy, morning colonoscopy, and the 2-L bowel preparation protocol. Meanwhile, patients receiving OSS had a beneficial bowel preparation score.

CONCLUSION

Compared with polyethylene glycol-based regimens, the OSS bowel preparation regimen significantly increased the PDR and ADR in patients undergoing colonoscopy.

3 liters of polyethylene glycol vs. standard bowel preparation have equal efficacy in a Chinese population: a randomized, controlled trial

BACKGROUND

The European Society of Gastrointestinal Endoscopy recommends 4L Polyethylene Glycol (PEG) as the standard regimen for bowel preparation (BP). The current study compared 3L and 4L PEG with regard to their effectiveness, tolerability, and safety among Chinese patients to identify the best bowel cleansing method for this population.

METHODS

The study employed a prospective, observer-blinded, randomized and controlled design in a high-volume endoscopic center. Consecutive patients undergoing colonoscopy were randomly assigned (1:1) to the 3L-PEG or 4L-PEG group. The quality of bowel cleansing, procedure time, adenoma detection rate (ADR), patient tolerance, and adverse events were compared.

RESULTS

A total of 330 patients were included in the study. After exclusions, 160 cases in the 3L-PEG group and 158 cases in the 4L-PEG group were included in the final analysis. The quality of bowel cleansing (Boston Bowel Preparation Scale) for both the whole intestine and each segment had no significant differences between the groups (P > 0.05). No significant differences were found with regard to procedure time or ADR. The incidences of adverse events such as nausea (P = 0.001), vomiting (P = 0.002), and bloating (P < 0.001) were lower in the 3L-PEG group. Moreover, there was a higher rate of satisfaction in the 3L-PEG group than in the 4L-PEG group (P = 0.009).

CONCLUSIONS

3L-PEG bowel cleansing represents an optimal alternative to a 4L-PEG preparation, showing similar efficacy and superior levels of satisfaction, acceptability, and safety among users. We recommend 3L PEG as a routine regimen in the clinical setting for Chinese patients. (ClinicalTrials.gov registration number: NCT03356015, registered in 29 November, 2017, https://www.

CLINICALTRIALS

gov/ct2/show/NCT03356015).

The Impact of the Colonoscopy Starting Position and Its Potential Outcomes

Based on the literature review, many studies have been inconclusive in regards to adenoma detection and procedural positioning during a colonoscopy. Scope looping can make cecal intubation challenging, changing the positioning of the patient and application of external abdominal pressure can overcome this difficulty. A colonoscopy in a prone position can overcome these challenges and reduce cecal intubation time. It can thus improve the safety of the patient and the staff by minimizing the movement of a sedated patient.

Screening and prevention of colorectal cancer

Mortality from colorectal cancer is reduced through screening and early detection; moreover, removal of neoplastic lesions can reduce cancer incidence. While understanding of the risk factors, pathogenesis, and precursor lesions of colorectal cancer has advanced, the cause of the recent increase in cancer among young adults is largely unknown. Multiple invasive, semi- and non-invasive screening modalities have emerged over the past decade. The current emphasis on quality of colonoscopy has improved the effectiveness of screening and prevention, and the role of new technologies in detection of neoplasia, such as artificial intelligence, is rapidly emerging. The overall screening rates in the US, however, are suboptimal, and few interventions have been shown to increase screening uptake. This review provides an overview of colorectal cancer, the current status of screening efforts, and the tools available to reduce mortality from colorectal cancer.

Effect of antifoaming agent on benign colorectal tumors in colonoscopy: A meta-analysis

BACKGROUND

Although several trials have shown that the addition of antifoaming agents to polyethylene glycol (PEG) can improve bowel preparation, whether PEG plus antifoaming agents have a beneficial role in the detection of benign tumors during colonoscopy has yet to be confirmed. Our aim was to clarify whether adding simethicone to PEG solution could improve the detection of benign colorectal tumors.

AIM

To clarify whether adding simethicone to PEG solution could improve the detection of benign colorectal tumors.

METHODS

The PubMed, EMBASE, and Cochrane Library databases were searched for articles published prior to September 2019. The outcomes included the detection rates of colorectal adenomas and polyps.

RESULT

Twenty studies were eligible. Although there was no difference in the colorectal adenoma detection rate (ADR), a significant effect of simethicone for diminutive adenomas (< 10 mm) was revealed in the group taking simethicone. We also found that simethicone could significantly improve the ADR in the proximal colon but did not affect the colorectal polyp detection rate. Furthermore, the subgroup analyses revealed a beneficial effect of simethicone on the ADR among Asians (P = 0.005) and those with an ADR < 25% (P = 0.003). Moreover, it was a significant finding that the low dose simethicone was as effective as the high dose one with respect to the detection of benign colorectal tumors.

CONCLUSION

In summary, the addition of simethicone to PEG might improve the detection of diminutive adenomas in the right colon by colonoscopy in Asia. Low-dose simethicone was recommended for the detection of benign colorectal tumors. However, large clinical trials are necessary to validate our results and determine the ideal dose of simethicone.

Colonoscopy screening and surveillance guidelines

The Colonoscopy Screening and Surveillance Guidelines were developed by the Japan Gastroenterological Endoscopy Society as basic guidelines based on the scientific methods. The importance of endoscopic screening and surveillance for both detection and post-treatment follow-up of colorectal cancer has been recognized as essential to reduce disease mortality. There is limited high-level evidence in this field; therefore, we had to focus on the consensus of experts. These clinical practice guidelines consist of 20 clinical questions and eight background knowledge topics that have been determined as the current guiding principles.

Colonoscopy in poorly prepped colons: a cost effectiveness analysis comparing standard of care to a new cleansing technology

Background

The objective of this Markov model lifetime cost-effectiveness analysis was to evaluate a new medical device technology which minimizes redo colonoscopies on the outcomes of cost, quality of life, and aversion of colorectal cancers (CRC).

Methods

A new technology (PureVu® System) which cleans inadequately prepped colons was evaluated using TreeAge 2019 software in patients who presented with inadequate prep in outpatient settings in the US. PureVu was compared to the standard of care (SOC). Peer reviewed literature was used to identify the CRC incidence cancers based on missing polyps. Costs for procedures were derived from 2019 Medicare and from estimated private payer reimbursements. Base case costs, sensitivity analysis and incremental cost effectiveness (ICE) were evaluated. The cost of PureVu was $750.

Results

Assuming a national average compliance rate of 60% for colonoscopy, the use of PureVu saved the healthcare system $833–$992/patient depending upon the insurer when compared to SOC. QALYs were also improved with PureVu mainly due to a lower incidence of CRCs. In sensitivity analysis, SOC becomes less expensive than PureVu when compliance to screening for CRC using colonoscopy is ≤ 28%. Also, in order for SOC to be less expensive than PureVu, the list price of PureVu would need to exceed $1753. In incremental cost effectiveness analysis, PureVu dominated SOC.

Conclusion

Using the PureVu System to improve bowel prep can save the healthcare system $3.1–$3.7 billion per year, while ensuring a similar quality of life and reducing the incidence of CRCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12962-021-00277-5.

Improving Adenoma Detection Rates: The Role of the Fecal Immunochemical Test

Background

There is limited knowledge about adenoma detection rates (ADRs) in patients with a positive fecal immunochemical test (FIT). We hypothesized that colonoscopy performed after FIT would result in higher ADRs.

Methods

We reviewed ADRs for colonoscopies performed after a positive FIT test and compared them to ADR rates for routine colonoscopy performed without an initial FIT test between November 2014 and March 2017 at multiple endoscopy sites.

Results

A total of 979 patients underwent a FIT testing in the Texas panhandle, of whom 12.1% (n=119) tested positive. Also, 32.8% (n=39) were found to have one or more tubular adenomatous polyps on final pathological examination. Among these patients, the majority were female (64.1%; n=25). Of the patients, 15.9% (n=19) had a hyperplastic polyp, 1.7% (n=2) had findings consistent with ulcerative colitis, and 0.8% (n=1) were positive for an adenocarcinoma. In the control group of 2,603 patients in whom routine colonoscopy was performed as the initial tool for screening, 719 were found to have one or more tubular adenomas, with an ADR rate of 27.5%. In this group, the cancer rate was found to be 1%.

Conclusions

There was a significant increase in the ADR when colonoscopy is conducted after a positive FIT test. Recommending colonoscopies after a positive FIT test will not only improve ADRs significantly but also lower the overall healthcare cost for screening colon cancer in this era of escalating healthcare costs.

Impact of simethicone on bowel cleansing during colonoscopy in Chinese patients

BACKGROUND

Four-liter polyethylene glycol (PEG) solutions are effective for bowel cleansing, but their large volume might hinder patient compliance. Due to the unique features of Asians, 4 L PEG might be a suboptimal bowel preparation in predominantly ethnically Asian countries. In view of this, a balance should be achieved between the volume and effectiveness. The ideal bowel cleansing regimen for a colonoscopy has yet to be determined in a Chinese population.

AIM

To compare the cleansing efficacy of 3 L PEG plus simethicone with 4 L PEG.

METHODS

A total of 291 patients were randomly allocated to two groups: Group 1 (n = 145) received 4 L split-dose PEG (4-P); group 2 (n = 146) received 3 L split-dose PEG plus simethicone (3-PS). Bowel-cleansing efficacy was evaluated by endoscopists using the Boston bowel preparation scale (BBPS) and the bubbles score.

RESULTS

Although there were no significant differences in the total BBPS score or the adequate rate of bowel preparation between the two groups, the BBPS score of the right-side colon was significantly higher in the 3-SP group (2.37 ± 0.54 vs 2.21 ± 0.78; P = 0.04). Moreover, the use of simethicone significantly reduced bubbles in all colon segments (P < 0.001). The mean withdrawal time was significantly shorter in the 3-PS group (8.8 ± 3.4 vs 9.6 ± 2.3; P = 0.02). Furthermore, significantly more proximal adenomas were detected in the 3-PS group (53.6% vs 45.7%; P = 0.03). In addition, the proportions of patients with nausea and bloating were significantly lower in the 3-SP group (P < 0.01 for both). More patients in the 3-PS group expressed willingness to repeat the bowel preparation (87.7% vs 76.6%, P = 0.01).

CONCLUSION

Three-liter PEG shows satisfactory bowel cleansing despite the decrease in dosage, and addition of simethicone with better bubble elimination and enhanced patient acceptance offers excellent potential impact on the detection of proximal adenomas in Chinese patients.

Quality Improvement of Bowel Preparation for Screening Colonoscopies: A Study of Hospital Team Resource Management in Taiwan

BACKGROUND AND OBJECTIVES

This study aimed to investigate the impact of patient education using a medical team resource management (TRM) method on the adequacy of bowel preparation.

METHODS

The study setting was a single hospital in northern Taiwan, and a total of 2104 (884 female, 1220 male) healthy subjects who underwent a health checkup colonoscopy screening were enrolled before and after the application of the TRM program intervention. The efficacy of the TRM intervention and the factors affecting bowel preparation were estimated using multivariate logistic regression.

RESULTS

The prevalence of adequate bowel preparation improved significantly from the preintervention period to the postintervention and validation periods, which had prevalence of 79.0%, 81.3%, and 84.0%, respectively. Using the preintervention period prevalence as a reference, the adjusted odds ratios (aORs) for adequate bowel preparation in the postintervention and validation periods were 2.199 (95% confidence interval [CI]: 1.538-3.142) and 2.035 (1.525-2.716), respectively. Men had a lower probability of adequate cleansing than women (aOR = 0.757; 95% CI = 0.598-0.957), and purgative containing polyethylene glycol had a lower probability of adequate cleansing than purgative containing sodium phosphate (aOR = 0.366; 95% CI: 0.277-0.483).

CONCLUSIONS

Bowel preparation quality for colonoscopy could be improved by enhancing patient education via TRM, and we suggest that effective quality improvement schemes should be proposed for health-screening programs.

Colonoscopy quality in community hospitals and nonhospital facilities in Korea

BACKGROUND/AIMS

High-quality colonoscopy is essential to reduce colorectal cancer-related deaths. Little is known about colonoscopy quality in non-academic practice settings. We aimed to evaluate the quality of colonoscopies performed in community hospitals and nonhospital facilities.

METHODS

Colonoscopy data were collected from patients referred to six tertiary care centers after receiving colonoscopies at community hospitals and nonhospital facilities. Based on their photographs, we measured quality indicators including cecal intubation rate, withdrawal time, adequacy of bowel preparation, and number of polyps.

RESULTS

Data from a total of 1,064 colonoscopies were analyzed. The overall cecal intubation rate was 93.1%. The median withdrawal time was 8.3 minutes, but 31.3% of colonoscopies were withdrawn within 6 minutes. Community hospitals had longer withdrawal time and more polyps than nonhospital facilities (median withdrawal time: 9.9 minutes vs. 7.5 minutes, p < 0.001; mean number of polyps: 3.1 vs. 2.3, p = 0.001). Board-certified endoscopists had a higher rate of cecal intubation than non-board-certified endoscopists (93.2% vs. 85.2%, p = 0.006). A total of 819 follow-up colonoscopies were performed at referral centers with a median interval of 28 days. In total, 2,546 polyps were detected at baseline, and 1,088 were newly identified (polyp miss rate, 29.9%). Multivariable analysis revealed that older age (odds ratio [OR], 1.032; 95% confidence interval [CI], 1.020 to 1.044) and male sex (OR, 1.719; 95% CI, 1.281 to 2.308) were associated with increased risk of missed polyps.

CONCLUSION

The quality of colonoscopies performed in community hospitals and nonhospital facilities was suboptimal. Systematic reporting, auditing, and feedback are needed for quality improvement.

Prevalence of Colorectal Neoplasms and Mortality in New Users of Low-Dose Aspirin With Lower Gastrointestinal Bleeding

BACKGROUND

Aspirin inhibits platelet function and may therefore accelerate early lower gastrointestinal bleeding (LGIB) from colorectal cancer (CRC) precursor polyps. The bleeding may increase endoscopic polyp detection.

STUDY QUESTION

To estimate the prevalence of polyps and CRC comparing new users of low-dose aspirin with nonusers who all received a diagnosis of LGIB and to investigate the mortality among these patients.

STUDY DESIGN

Using Danish nationwide health registries, we conducted a cohort study (2006-2013) of all new aspirin users who also received a diagnosis of LGIB (n = 40,578). Each new user was matched with 5 nonusers with LGIB by gender and age at the LGIB diagnosis date.

MEASURES AND OUTCOMES

We computed the prevalence and prevalence ratios (PRs) of colorectal polyps and CRCs, and the mortality ratios within 6 months after the LGIB, comparing new users with nonusers.

RESULTS

We identified 1038 new aspirin users and 5190 nonusers with LGIB. We observed 220 new users and 950 nonusers recorded with endoscopically detected polyps. New aspirin users had a higher prevalence of conventional {PR = 1.28 [95% confidence interval (CI): 1.06-1.55]} and serrated [PR = 1.31 (95% CI: 0.95-1.80)] polyps. New users and nonusers had a similar prevalence of CRC [PR = 1.04 (95% CI: 0.77-1.39)]. However, after stratifying by location of CRC, the prevalence of proximal tumors was lower [PR = 0.71 (95% CI: 0.35-1.43)] in new users than in nonusers. No difference in mortality was observed.

CONCLUSIONS

These findings indicate that new use of low-dose aspirin is associated with an increased detection of colorectal polyps compared with nonuse.

AGA White Paper: Roadmap for the Future of Colorectal Cancer Screening in the United States

The American Gastroenterological Association's Center for Gastrointestinal Innovation and Technology convened a consensus conference in December 2018, entitled, "Colorectal Cancer Screening and Surveillance: Role of Emerging Technology and Innovation to Improve Outcomes." The goal of the conference, which attracted more than 60 experts in screening and related disciplines, including the authors, was to envision a future in which colorectal cancer (CRC) screening and surveillance are optimized, and to identify barriers to achieving that future. This White Paper originates from that meeting and delineates the priorities and steps needed to improve CRC outcomes, with the goal of minimizing CRC morbidity and mortality. A one-size-fits-all approach to CRC screening has not and is unlikely to result in increased screening uptake or desired outcomes owing to barriers stemming from behavioral, cultural, and socioeconomic causes, especially when combined with inefficiencies in deployment of screening technologies. Overcoming these barriers will require the following: efficient utilization of multiple screening modalities to achieve increased uptake; continued development of noninvasive screening tests, with iterative reassessments of how best to integrate new technologies; and improved personal risk assessment to better risk-stratify patients for appropriate screening testing paradigms.

Efficacy and Patient Tolerability Profiles of Probiotic Solution with Bisacodyl Versus Conventional Cleansing Solution for Bowel Preparation: A Prospective, Randomized, Controlled Trial

Although adequate bowel preparation is essential in screening colonoscopy, patient intolerability to bowel cleansing agents is problematic. Recently, a probiotic mixture solution with bisacodyl emerged to improve patient tolerability. We investigated the efficacy, safety, and patient tolerability profiles of probiotics with bisacodyl versus conventional polyethylene glycol (PEG) solution for bowel preparation for screening colonoscopies in healthy patients in this prospective, randomized, case-control study. In total, 385 volunteers were randomly assigned to receive 2 L of water + 200 mL of probiotic solution (case group, n = 195) or 4 L of PEG solution (control group, n = 190). The efficacy of the bowel cleansing was evaluated using the Ottawa scale system, polyp detection rate, and adenoma detection rate, and the patient tolerability profiles were assessed using a questionnaire. The demographics were not significantly different between groups. When the Ottawa score for each bowel segment was stratified into an adequate vs. inadequate level (Ottawa score ≤ 3 vs. >3), there were no statistical differences between groups in each segment of the colon. There were no significant differences in the polyp and adenoma detection rates between groups (38.42% vs. 32.42, p = 0.30; 25.79% vs. 18.97%, p = 0.11). The case group showed significantly fewer events than the control group, especially nausea, vomiting, and abdominal bloating events. Regarding the overall satisfaction grade, the case group reported significantly more “average” scores (95% vs. 44%, p < 0.001) and were more willing to use the same agents again (90.26% vs. 61.85%, p < 0.001). As patient compliance with bowel preparation agents is associated with an adequate level of bowel cleansing, a probiotic solution with bisacodyl might be a new bowel preparation candidate, especially in patients who show a poor compliance with conventional bowel preparation agents.

Improved detection of colorectal adenomas by high-quality colon cleansing

Background and study aims  Reliable adenoma detection requires "adequate" bowel preparation. The adenoma detection rate (ADR) was assessed in patients with high-quality (stool-free) cleansing versus adequate cleansing. Patients and methods  This study was a post-hoc combined analysis of three randomized trials individually powered for cleansing quality assessment. Treatment-independent ADR was assessed versus colon cleansing quality by central readers using the Harefield Cleansing Scale (HCS) and the Boston Bowel Preparation Scale (BBPS). The number needed to treat (NNT) to find an additional patient with at least one adenoma was calculated for high-quality versus adequate-quality cleansing. Results  A total of 1749 patients were included. ADR increased with high-quality versus adequate-quality cleansing: HCS grade A versus B, 39 % (94/242) versus 27 % (336/1229); NNT = 8.7; P  < 0.001. ADR also increased with high-quality versus uniform adequate segmental cleansing scores: HCS grade A versus uniform segmental scores 2, 39 % (94/242) versus 26 % (97/379); NNT = 7.5; P  < 0.001. ADR increased with top-quality versus adequate segmental cleansing scores: HCS uniform segmental scores 4 versus 2, 54 % (21/39) versus 26 % (97/379); NNT = 3.6; P  < 0.001. ADR increased with BBPS 9 versus 6, 43 % (71/166) versus 26 % (247/950); NNT = 6.0; P  < 0.001. Right colon ADR increased with top-quality versus adequate cleansing: HCS 4 versus 2, 20 % (25/122) versus 11 % (121/1117); NNT = 10.4; P  < 0.001 and BBPS 3 versus 2, 15 % (42/284) versus 11 % (130/1192); NNT = 25.8; P  = 0.033. Conclusions  High-quality colon cleansing improves adenoma detection, and it should be a priority for bowel preparations for colonoscopy.

High-quality colon cleansing and multiple neoplasia detection with 1L NER1006 versus mid-volume options: Post hoc analysis of phase 3 clinical trials

Background and study aims  Multiple neoplasia increase the risk of colorectal cancer. High-quality cleansing may improve adenoma detection. We assessed whether a new bowel preparation can improve colon cleansing and multiple lesion detection. Patients and methods  This post hoc analysis of two randomized clinical trials in Europe and the US assessed the per study and combined cleansing efficacy of overnight split dosing with (preparation + clear fluids) 1 + 1 L polyethylene glycol (PEG) NER1006 versus 2 + 1 L PEG + ascorbate (2LPEG) or 1 + 2 L oral sulfate solution (OSS) combined. Treatment-blinded central readers assessed cleansing quality using the Harefield Cleansing Scale (HCS). Patients with full segmental scoring were included. HCS segmental scores 0-4 (high-quality = HCS 3-4) were analyzed for NER1006 versus 2LPEG/OSS. Mean number of polyps or adenomas per patient (MPP/MAP) was calculated for treatments in patients with at least one polyp or adenoma. Results  In 1037 patients, NER1006 attained a greater rate of HCS 3 scores (29 % vs. 20 %; P  < 0.001) and HCS 4 scores (20 % vs. 17 %; P  = 0.007) versus 2LPEG/OSS. More polyps (678 versus 585) and adenomas (397 versus 331) were detected with NER1006 (N = 517) versus 2LPEG/OSS (N = 520). In all neoplasia-positive patients, with increasing minimal per-patient neoplasia multiplicity from 1 to 10, NER1006 numerically improved MPP (difference ± SE: 0.48 ± 0.24 to 3.89 ± 3.37) and MAP (0.47 ± 0.26 to 7.50 ± 9.00) versus 2LPEG/OSS. Conclusions  Low-volume NER1006 enhances high-quality cleansing versus medium-volume 2LPEG or OSS, individually and when combined. NER1006 may consequently facilitate the detection of multiple neoplasia in patients.

The importance of colonoscopy bowel preparation for the detection of colorectal lesions and colorectal cancer prevention

Background and study aims  Colonoscopy for colorectal cancer (CRC) screening has reduced CRC incidence and mortality and improved prognosis. Optimal bowel preparation and high-quality endoscopic technique facilitate early CRC detection. This review provides a narrative on the clinical importance of bowel preparation for colonoscopy and highlights available bowel preparations. Methods  A PubMed search was conducted through June 2019 to identify studies evaluating clinical outcomes, efficacy, safety, and tolerability associated with bowel preparation for CRC screening-related colonoscopy. Results  Selecting the optimal bowel preparation regimen is based on considerations of efficacy, safety, and tolerability, in conjunction with individual patient characteristics and preferences. Available bowel preparations include high-volume (4 L) and low-volume (2 L and 1 L), polyethylene glycol (PEG) solutions, sodium sulfate, sodium picosulfate/magnesium oxide plus anhydrous citric acid, sodium phosphate tablets, and the over-the-counter preparations magnesium citrate and PEG-3350. These preparations may be administered as a single dose on the same day or evening before, or as two doses administered the same day or evening before/morning of colonoscopy. Ingesting at least half the bowel preparation on the day of colonoscopy (split-dosing) is associated with higher adequate bowel preparation quality versus evening-before dosing (odds ratio [OR], 2.5; 95 % confidence interval [CI], 1.9-3.4). Conclusions  High-quality bowel preparation is integral for optimal CRC screening/surveillance by colonoscopy. Over the last 30 years, patients and providers have gained more options for bowel preparation, including low-volume agents with enhanced tolerability and cleansing quality that are equivalent to 4 L preparations. Split-dosing is preferred for achieving a high-quality preparation.

Similar Adenoma Detection Rates in Colonoscopic Procedures of Patients with Spinal Cord Injury Compared to Controls

BACKGROUND

Cancer is a major cause of death in patients with spinal cord injury (SCI). Preventive strategies, such as colonoscopy, deal with higher burdens that may lead to lower quality.

AIMS

The primary objective was to evaluate the adenoma detection rate. Secondary objectives were to investigate other quality indicators regarding bowel preparation, sedation, and endoscopy.

METHODS

Consecutive SCI patients who had undergone colonoscopy from 2003 to 2014 were assigned to a control group matched for age, gender, and year of procedure and reviewed retrospectively.

RESULTS

Bowel preparation lasted longer (3.6 ± 1.5 vs. 1.2 ± 0.6 days, p = 0.001), achieved unsatisfactory cleansing results more often (23.7 vs. 3.6%) and caused more adverse events in 236 SCI compared to 414 control patients. Colonoscopy needed a longer time (36.9 vs. 25.0 min) and remained incomplete more often (24.6 vs. 4.6%), resulting in more re-colonoscopies (14.8 vs. 4.3%). Endoscopy- and sedation-related adverse events were equal. However, neither overall nor size-dependent polyp (30.9 vs. 34.8%), adenoma (21.2 vs. 21.0%), advanced adenoma (6.8 vs. 7.2%), or cancer (1.7 vs. 2.0%) detection rates differed.

CONCLUSION

Despite intensified protocols, bowel preparation shows inferior results in SCI patients; colonoscopy needs more effort to succeed but achieves a comparable quality.

Predicting colorectal cancer risk from adenoma detection via a two-type branching process model

Despite advances in the modeling and understanding of colorectal cancer development, the dynamics of the progression from benign adenomatous polyp to colorectal carcinoma are still not fully resolved. To take advantage of adenoma size and prevalence data in the National Endoscopic Database of the Clinical Outcomes Research Initiative (CORI) as well as colorectal cancer incidence and size data from the Surveillance Epidemiology and End Results (SEER) database, we construct a two-type branching process model with compartments representing adenoma and carcinoma cells. To perform parameter inference we present a new large-size approximation to the size distribution of the cancer compartment and validate our approach on simulated data. By fitting the model to the CORI and SEER data, we learn biologically relevant parameters, including the transition rate from adenoma to cancer. The inferred parameters allow us to predict the individualized risk of the presence of cancer cells for each screened patient. We provide a web application which allows the user to calculate these individual probabilities at https://ccrc-eth.shinyapps.io/CCRC/. For example, we find a 1 in 100 chance of cancer given the presence of an adenoma between 10 and 20mm size in an average risk patient at age 50. We show that our two-type branching process model recapitulates the early growth dynamics of colon adenomas and cancers and can recover epidemiological trends such as adenoma prevalence and cancer incidence while remaining mathematically and computationally tractable.

Colorectal cancer is a major public health burden. The development of colorectal cancer starts with the mutational initiation of non-cancerous growths in the form of benign adenomatous polyps. These adenomas grow over time with the potential to develop into carcinomas. Many mathematical and simulation-based models have been used to gain insight into this process. We aimed to understand rates of adenoma growth and transition into carcinomas, to enable better planning of colorectal cancer screening strategies. To this end, we expand the two-type branching process model, and fit it on data describing the frequency of sizes of adenomas and carcinomas. The results provide new, data-based, estimates of the rates of development for colorectal cancer.

Cost-utility of colorectal cancer screening at 40 years old for average-risk patients

The incidence of colorectal cancer (CRC) is increasing in patients under the age of 50. The purpose of this study was to assess the cost-utility of available screening modalities starting at 40 years in the general population compared to standard screening at 50 years old. A decision tree modeling average-risk of CRC in the United States population was constructed for the cost per quality-adjusted life year (QALY) of the five most common and effective CRC screening modalities in average-risk 40-year olds versus deferring screening until 50 years old (standard of care) under a limited societal perspective. All parameters were derived from existing literature. We evaluated the incremental cost-utility ratio of each comparator at a willingness-to-pay threshold of $50,000/QALY and included multivariable probabilistic sensitivity analysis. All screening modalities assessed were more cost-effective with increased QALYs than current standard care (no screening until 50). The most favorable intervention by net monetary benefit was flexible sigmoidoscopy ($3284 per person). Flexible sigmoidoscopy, FOBT, and FIT all dominated the current standard of care. Colonoscopy and FIT-DNA were both cost-effective (respectively, $4777 and $11,532 per QALY). The cost-effective favorability of flexible sigmoidoscopy diminished relative to colonoscopy with increasing willingness-to-pay. Regardless of screening modality, CRC screening at 40 years old is cost-effective with increased QALYs compared to current screening initiation at 50 years old, with flexible sigmoidoscopy most preferred. Consideration should be given for a general recommendation to start screening at age 40 for average risk individuals.

High-Intensity Versus Low-Intensity Surveillance for Patients With Colorectal Adenomas: A Cost-Effectiveness Analysis

BACKGROUND

Surveillance of patients with colorectal adenomas has limited long-term evidence to support current practice.

OBJECTIVE

To compare the lifetime benefits and costs of high- versus low-intensity surveillance.

DESIGN

Microsimulation model.

DATA SOURCES

U.S. cancer registry, cost data, and published literature.

TARGET POPULATION

U.S. patients aged 50, 60, or 70 years with low-risk adenomas (LRAs) (1 to 2 small adenomas) or high-risk adenomas (HRAs) (3 to 10 small adenomas or ≥1 large adenoma) removed after screening with colonoscopy or fecal immunochemical testing (FIT).

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTION

No further screening or surveillance, routine screening after 10 years, low-intensity surveillance (10 years after LRA removal and 5 years after HRA removal), and high-intensity surveillance (5 years after LRA removal and 3 years after HRA removal).

OUTCOME MEASURES

Colorectal cancer (CRC) incidence and incremental cost-effectiveness.

RESULTS OF BASE-CASE ANALYSIS

Without surveillance or screening, lifetime CRC incidence for patients aged 50 years was 10.9% after LRA removal and 17.2% after HRA removal at screening colonoscopy. Subsequent colonoscopic screening, low-intensity surveillance, or high-intensity surveillance decreased incidence by 39%, 46% to 48%, and 55% to 56%, respectively. Incidence of CRC and surveillance benefits were higher for adenomas detected at FIT screening and lower for older patients. High-intensity surveillance cost less than $30 000 per quality-adjusted life-year (QALY) gained compared with low-intensity surveillance.

RESULTS OF SENSITIVITY ANALYSIS

High-intensity surveillance cost less than $100 000 per QALY gained in most alternative scenarios for adenoma recurrence, CRC incidence, longevity, quality of life, screening ages, surveillance ages, test performance, disutilities, and cost.

LIMITATION

Few surveillance outcome data exist.

CONCLUSION

The model suggests that high-intensity surveillance as recommended in the United States provides modest but clinically relevant benefits over low-intensity surveillance at acceptable cost.

PRIMARY FUNDING SOURCE

National Cancer Institute.

A comparison of 2 distal attachment mucosal exposure devices: a noninferiority randomized controlled trial

BACKGROUND AND AIMS

Endocuff (Arc Medical Design, Leeds, UK) and Endocuff Vision (Arc Medical Design, Leeds, UK) are effective mucosal exposure devices for improving polyp detection during colonoscopy. AmplifEYE (Medivators Inc, Minneapolis, Minn, USA) is a device that appears similar to the Endocuff devices but has received minimal clinical testing.

METHODS

We performed a randomized controlled clinical trial using a noninferiority design to compare Endocuff Vision with AmplifEYE.

RESULTS

The primary endpoint of adenomas per colonoscopy was similar in AmplifEYE at 1.63 (standard deviation 2.83) versus 1.51 (2.29) with Endocuff Vision (P = .535). The 95% lower confidence limit was 0.88 for ratio of means, establishing noninferiority of AmplifEYE (P = .008). There was no difference between the arms for mean insertion time, and mean inspection time (withdrawal time minus polypectomy time and time for washing and suctioning) was shorter with AmplifEYE (6.8 minutes vs 6.9 minutes, P = .042).

CONCLUSIONS

AmplifEYE is noninferior to Endocuff Vision for adenoma detection. The decision on which device to use can be based on cost. Additional comparisons of AmplifEYE with Endocuff by other investigators are warranted. (Clinical trial registration number: NCT03560128.).

Changes in screening colonoscopy following Medicare reimbursement and cost-sharing changes

OBJECTIVES

To compare existing algorithms for classifying screening vs diagnostic colonoscopies and to quantify the increase in screening colonoscopy rates when Medicare began reimbursement in 2001 and when the Affordable Care Act (ACA) eliminated cost-sharing.

DATA SOURCES

Twenty percent random sample of fee-for-service (FFS) Medicare claims, 2000-2012.

STUDY DESIGN

Using recent administrative codes as tarnished gold standards, we examined the sensitivity and specificity of five published algorithms for classifying colonoscopies and calculated annual screening colonoscopy rates. We estimated the change in rates after Medicare began reimbursement and used difference-in-differences analysis to estimate the effects of eliminating cost-sharing by comparing states with and without a mandate to cover screening colonoscopy prior to the ACA.

FINDINGS

Model-based algorithms have higher sensitivity (0.53-0.99) than expert-based algorithms (0.35-0.39), but lower specificity (0.43-0.65 vs 0.79-0.88). All algorithms detected increases in screening from both Medicare's reimbursement change (range: 24-93/10 000) and the 2011 cost-sharing change (range: 1.1-34/10 000). Difference-in-difference estimates of the ACA's effect varied from 51 to 155 tests per 10 000 depending on the algorithm.

CONCLUSIONS

Screening colonoscopy rates increased after eliminating cost-sharing in 2011, but the increase's size varied depending on the algorithm used to classify the indication. Improvements are needed in Medicare coding for screening.

Effect of supplemental simethicone for bowel preparation on adenoma detection during colonoscopy: A meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Although several randomized controlled trials (RCTs) have reported that supplemental simethicone (SIM) can improve bowel preparation based on polyethylene glycol, there is no consensus as to whether SIM can ultimately increase the adenoma detection rate (ADR) during colonoscopy. A meta-analysis was performed to assess the effect of SIM on ADR during colonoscopy.

METHODS

Databases including PubMed, EMBASE, and the Cochrane Library were searched to find relevant RCTs. RCTs evaluating the effect of pre-procedure SIM on the ADR during colonoscopy were finally included, and fixed effect models were applied.

RESULTS

Six trials involving 1855 patients were finally included. The present meta-analysis suggested that the ADR during colonoscopy was significantly increased by supplemental SIM (27.9% vs 23.3%, P = 0.02), with a relative risk of 1.20 (95% confidence interval 1.03-1.39). Subgroup analysis suggested that supplemental SIM may be more useful to improve ADR during colonoscopy in endoscopic centers with low baseline ADR.

CONCLUSIONS

Supplemental SIM for bowel preparation based on polyethylene glycol is useful to improve the ADR during colonoscopy.

Evidence-based sizing of non-inferiority trials using decision models

Background

There are significant challenges to the successful conduct of non-inferiority trials because they require large numbers to demonstrate that an alternative intervention is “not too much worse” than the standard. In this paper, we present a novel strategy for designing non-inferiority trials using an approach for determining the appropriate non-inferiority margin (δ), which explicitly balances the benefits of interventions in the two arms of the study (e.g. lower recurrence rate or better survival) with the burden of interventions (e.g. toxicity, pain), and early and late-term morbidity.

Methods

We use a decision analytic approach to simulate a trial using a fixed value for the trial outcome of interest (e.g. cancer incidence or recurrence) under the standard intervention (p_S) and systematically varying the incidence of the outcome in the alternative intervention (p_A). The non-inferiority margin, p_A – p_S = δ, is reached when the lower event rate of the standard therapy counterbalances the higher event rate but improved morbidity burden of the alternative. We consider the appropriate non-inferiority margin as the tipping point at which the quality-adjusted life-years saved in the two arms are equal.

Results

Using the European Polyp Surveillance non-inferiority trial as an example, our decision analytic approach suggests an appropriate non-inferiority margin, defined here as the difference between the two study arms in the 10-year risk of being diagnosed with colorectal cancer, of 0.42% rather than the 0.50% used to design the trial. The size of the non-inferiority margin was smaller for higher assumed burden of colonoscopies.

Conclusions

The example demonstrates that applying our proposed method appears feasible in real-world settings and offers the benefits of more explicit and rigorous quantification of the various considerations relevant for determining a non-inferiority margin and associated trial sample size.

Risk of Malignancy in Adenomas Detected During Screening Colonoscopy

BACKGROUND & AIMS

A higher incidence of proximal interval cancers after colonoscopy has been reported in several follow-up studies. One possible explanation for this might be that proximally located adenomas have greater malignant potential. The aim of the present study was to assess the risk of malignancy in proximal versus distal adenomas in patients included in a large screening colonoscopy database; adenoma shape and the patients' age and sex distribution were also analyzed.

METHODS

Data for 2007-2012 from the German National Screening Colonoscopy Registry, including 594,614 adenomas identified during 2,532,298 screening colonoscopies, were analyzed retrospectively. The main outcome measure was the rate of high-grade dysplasia (HGD) in adenomas, used as a surrogate marker for the risk of malignancy. Odds ratios (ORs) for the rate of HGD found in adenomas were analyzed in relation to patient- and adenoma-related factors using multivariate analysis.

RESULTS

HGD histology was noted in 20,873 adenomas (3.5%). Proximal adenoma locations were not associated with a higher HGD rate. The most significant risk factor for HGD was adenoma size (OR 10.36 ≥1 cm vs <1 cm), followed by patient age (OR 1.26 and 1.46 for age groups 65-74 and 75-84 vs 55-64 years) and sex (OR 1.15 male vs female). In comparison with flat adenomas as a reference lesion, sessile lesions had a similar HGD rate (OR 1.02) and pedunculated adenomas had a higher rate (OR 1.23). All associations were statistically significant (P ≤ .05).

CONCLUSIONS

In this large screening database, it was found that the rates of adenomas with HGD are similar in the proximal and distal colon. The presence of HGD as a risk marker alone does not explain higher rates of proximal interval colorectal cancer. We suggest that certain lesions (flat, serrated lesions) may be missed in the proximal colon and may acquire a more aggressive biology over time. A combination of endoscopy-related factors and biology may therefore account for higher rates of proximal versus distal interval colorectal cancer.

New-generation full-spectrum endoscopy versus standard forward-viewing colonoscopy: a multicenter, randomized, tandem colonoscopy trial (J-FUSE Study)

BACKGROUND AND AIMS

Although colonoscopy is the criterion standard for detection of colorectal adenomas, some adenomas are missed. Full-spectrum endoscopy (FUSE) allows for observation with a 330-degree angle of view, which is expected to decrease the miss rate. However, no consensus has been reached regarding the superiority of FUSE over standard forward-viewing colonoscopy (SFVC) for detection of adenomas; we therefore compared new-generation FUSE and SFVC regarding colorectal adenoma miss rate (AMR) in this, the first reported randomized control trial using new-generation FUSE.

METHODS

We enrolled individuals aged 40 to 75 years who had been referred for screening, surveillance, fecal occult blood test positivity, or symptoms in a prospective randomized trial of tandem colonoscopy in 8 institutions. Patients were randomly assigned (1:1) via computer-generated stratified randomization. Neither the endoscopists nor patients were blinded to the allocation. The primary endpoint was AMR per patient (AMR-PP).

RESULTS

We enrolled 345 patients and included 319 in the per-protocol analyses. AMR-PP was significantly lower with FUSE (11.7%; 95% confidence interval [CI], 8.0%-15.4%) than with SFVC (22.9%; 95% CI, 17.5%-28.3%; P < .001). AMR-PP for lesions ≤5 mm in size was significantly lower with FUSE (10.4%; 95% CI, 6.5%-14.3%) than with SFVC (20.0%; 95% CI, 14.4%-25.6%; P = .0057). Furthermore, AMR-PP in the ascending colon was significantly lower with FUSE (4.3%; 95% CI, 1.4%-7.2%) than with SFVC (10.6%; 95% CI, 6.1%-15.1%; P = .0212).

CONCLUSIONS

FUSE is superior to SFVC regarding both AMR-PP and AMR; additionally, AMR-PP is both significantly lower with FUSE than SFVC for lesions ≤5 mm in size and in the ascending colon. (Clinical trial registration number: UMIN000020448.).

High-definition colonoscopy versus Endocuff versus EndoRings versus full-spectrum endoscopy for adenoma detection at colonoscopy: a multicenter randomized trial

BACKGROUND AND AIMS

Devices used to improve polyp detection during colonoscopy have seldom been compared with each other.

METHODS

We performed a 3-center prospective randomized trial comparing high-definition (HD) forward-viewing colonoscopy alone to HD with Endocuff to HD with EndoRings to the full spectrum endoscopy (FUSE) system. Patients were age ≥50 years and had routine indications and intact colons. The study colonoscopists were all proven high-level detectors. The primary endpoint was adenomas per colonoscopy (APC).

RESULTS

Among 1188 patients who completed the study, APC with Endocuff (APC mean ± standard deviation: 1.82 ± 2.58), EndoRings (1.55 ± 2.42), and standard HD colonoscopy (1.53 ± 2.33) were all higher than FUSE (1.30 ± 1.96; P < .001 for APC). The APC for Endocuff was higher than standard HD colonoscopy (P = .014). Mean cecal insertion times with FUSE (468 ± 311 seconds) and EndoRings (403 ± 263 seconds) were both longer than with Endocuff (354 ± 216 seconds; P = .006 and .018, respectively).

CONCLUSIONS

For high-level detectors at colonoscopy, forward-viewing HD instruments dominate the FUSE system, indicating that for these examiners image resolution trumps angle of view. Further, Endocuff is a dominant strategy over EndoRings and no mucosal exposure device on a forward-viewing HD colonoscope. (Clinical trial registration number: NCT02345889.).

Research progress on patient comfort during bowel preparation

Bowel preparation is one of the key and necessary steps for preoperative preparations of multiple operations such as electronic colonoscopy, capsule endoscopy, barium X-ray, colorectal surgery, gynecology surgery, and urology surgery. Although better methods for bowel preparation have been explored continuously, patient intolerance still exists during the current bowel preparation process. Adverse reactions such as nausea and vomiting often occur, leading to poor comfort experience and affecting the patient's compliance and bowel preparation results. This article reviews the factors influencing patient comfort during bowel preparation and the corresponding interventions.

Impact of differences in adenoma and proximal serrated polyp detection rate on the long-term effectiveness of FIT-based colorectal cancer screening

BACKGROUND

Both the adenoma detection rate (ADR) and proximal serrated polyp detection rate (PSPDR) vary among endoscopists. It is unclear how these variations influence colorectal cancer (CRC) screening effectiveness. We evaluated the effect of variation in these detection rates on the long-term impact of fecal immunochemical test (FIT) based screening.

METHODS

The Adenoma and Serrated pathway to Colorectal CAncer (ASCCA) model was set up to simulate the Dutch national biennial FIT-based CRC screening program between 2014 and 2044. Adherence to FIT and colonoscopy was 73 and 92%. Besides a 'no screening scenario', several screening scenarios varying in ADR and PSPDR were evaluated. Using the available literature on colonoscopy miss rates led to a base-case ADR of 59% and PSPDR of 11%, which were varied with intervals of 3 and 2%.

RESULTS

Compared to no screening, FIT-screening in the base-case scenario reduced long-term mortality with 51.8%. At a fixed PSPDR of 11%, an increase in ADR from 44 to 62% would result in a 10.7% difference in mortality reduction. Using a fixed ADR of 59%, changing the PSPDR from 3 to 15% did not substantially influence long-term mortality (51.0 to 52.3%).

CONCLUSIONS

An increase in ADR gradually reduces CRC burden in a FIT-based screening program, whereas an increase in PSPDR only minimally influences long-term outcomes at a population-level. The limited effect of the PSPDR can be explained by the limited sensitivity of FIT for serrated polyps (SPs). Other triage modalities aiming to detect relevant SPs should be explored.

Methods for certification in colonoscopy - a systematic review

INTRODUCTION

Reliable, valid, and feasible assessment tools are essential to ensure competence in colonoscopy. This study aims to provide an overview of the existing assessment methods and the validity evidence that supports them.

METHODS

A systematic search was conducted in October 2016. Pubmed, EMBASE, and PsycINFO were searched for studies evaluating assessment methods to ensure competency in colonoscopy. Outcome variables were described and evidence of validity was explored using a contemporary framework.

RESULTS

Twenty-five observational studies were included in the systematic review. Most studies were based on small sample sizes. The studies were categorized after outcome measures into five groups: Clinical process related outcome metrics (n = 2), direct observational colonoscopy assessment (n = 8), simulator based metrics (n = 11), automatic computerized metrics (n = 2), and self-assessment (n = 1). Validity score varied among the studies and only five studies presented sufficient evidence to recommend the tool for clinical assessment.

CONCLUSIONS

The objectives vary throughout the presented tools. Some tools are global tools where others focus on procedural technical skill assessment or even part-task skills. There is a tendency in the most recent studies towards more specific assessment of technical skills. The majority of assessment methods lack sufficient validity evidence.

A Nationwide Survey and Needs Assessment of Colonoscopy Quality Assurance Programs in the VA

Variability exists in quality documentation, measurement, and reporting practices of colonoscopy screening in VA facilities, and most do not have formal performance improvement plans.

Colonoscopy surveillance for high risk polyps does not always prevent colorectal cancer

AIM

To determine the frequency and risk factors for colorectal cancer (CRC) development among individuals with resected advanced adenoma (AA)/traditional serrated adenoma (TSA)/advanced sessile serrated adenoma (ASSA).

METHODS

Data was collected from medical records of 14663 subjects found to have AA, TSA, or ASSA at screening or surveillance colonoscopy. Patients with inflammatory bowel disease or known genetic predisposition for CRC were excluded from the study. Factors associated with CRC developing after endoscopic management of high risk polyps were calculated in 4610 such patients who had at least one surveillance colonoscopy within 10 years following the original polypectomy of the incident advanced polyp.

RESULTS

84/4610 (1.8%) patients developed CRC at the polypectomy site within a median of 4.2 years (mean 4.89 years), and 1.2% (54/4610) developed CRC in a region distinct from the AA/TSA/ASSA resection site within a median of 5.1 years (mean 6.67 years). Approximately, 30% (25/84) of patients who developed CRC at the AA/TSA/ASSA site and 27.8% (15/54) of patients who developed CRC at another site had colonoscopy at recommended surveillance intervals. Increasing age; polyp size; male sex; right-sided location; high degree of dysplasia; higher number of polyps resected; and piecemeal removal were associated with an increased risk for CRC development at the same site as the index polyp. Increasing age; right-sided location; higher number of polyps resected and sessile endoscopic appearance of the index AA/TSA/ASSA were significantly associated with an increased risk for CRC development at a different site.

CONCLUSION

Recognition that CRC may develop following AA/TSA/ASSA removal is one step toward improving our practice efficiency and preventing a portion of CRC related morbidity and mortality.

Predictors of post-colonoscopy emergency department use

BACKGROUND AND AIMS

Unplanned hospital visits within 7 days of colonoscopy were recently proposed as a quality measure. It is unknown whether patient, procedure, or endoscopist characteristics predict post-colonoscopy emergency department (ED) visits. Our aim was to determine the incidence and relatedness of ED visits within 7 days of colonoscopy and to identify predictors of post-colonoscopy ED use.

METHODS

In this retrospective, single-center, cohort study, we evaluated outpatient colonoscopies performed at a tertiary academic medical center or affiliated facility between January 2008 and September 2013. We determined the incidence of ED visits within 7 days of colonoscopy and the relatedness of the ED visit to the procedure. We assessed for independent factors associated with ED use within 7 days using logistic regression analysis.

RESULTS

We reviewed 50,319 colonoscopies performed on 44,082 individuals (47% male, median age 59 years) by 40 endoscopists. There were 382 (0.76%) ED visits after colonoscopy, of which 68% were related to the procedure. On multivariate analysis, recent ED visit (odds ratio [OR], 16.60; 95% confidence interval [CI], 12.83-21.48; P < .001), EMR (OR, 4.69; 95% CI, 2.82-7.79; P < .001), number of medication classes (OR, 1.18; 95% CI, 1.11-1.26; P < .001), endoscopist adenoma detection rate (ADR) (OR, 1.14; 95% CI, 1.01-1.29; P = .029), and white race (OR, 0.77; 95% CI, 0.62-0.97; P = .028) were identified as independent variables associated with ED visits after colonoscopy.

CONCLUSIONS

Increased patient complexity, higher endoscopist ADR, and EMR were associated with increased ED use after colonoscopy. Patients at high risk for an unplanned hospital visit within 7 days should be targeted for quality improvement efforts to reduce adverse events and cost.

Regional colorectal cancer screening program using colonoscopy on an island: a prospective Nii-jima study

Objective

Colorectal cancer screening program using fecal immunochemical test had been conducted on an isolated island named Nii-jima. However, the participation rate of the program had been approximately 12%, which was lower than average level of Japan. This study aimed to evaluate the participation rate, safety and efficacy of a colorectal cancer screening program using colonoscopy on the island.

Methods

Educational campaigns were actively conducted every month using information bulletins and special propaganda pamphlets. The primary recommended modality was colonoscopy, followed by fecal immunochemical test. The participants of this program were 1671 individuals aged 40–79 years (men, 819; women, 852).

Results

A total of 789 (47.2%) individuals provided consent for this screening program, and 89.2% (704/789) of participants chose colonoscopy as the primary screening procedure. The completion rate of total colonoscopy was 99.7%, and there was no complication during this program. Detection rates of invasive cancer, intramucosal cancer, advanced neoplasia and any adenoma were 0.9% (n = 6), 2.4% (n = 17), 11.8% (n = 83) and 50.0% (n = 352), respectively. The adenoma detection rate and incidence of advanced neoplasia were significantly higher in men than in women in all age groups.

Conclusions

The colorectal cancer screening program using colonoscopy that was conducted on an island achieved considerably higher participation rate than the conventional screening program using fecal immunochemical test. Completion rate and safety of screening colonoscopy were excellent during this program.

Impact of adenoma detection on the benefit of faecal testing vs. colonoscopy for colorectal cancer

Colonoscopy quality, as measured by adenoma detection rates, varies widely across providers and is inversely related to patients' post-colonoscopy cancer risk. This has unknown consequences for the benefits of faecal immunochemical testing (FIT) vs. primary colonoscopy screening for colorectal cancer. Using an established microsimulation model, we predicted the lifetime colorectal cancer incidence and mortality benefits of annual FIT vs. 10-yearly colonoscopy screening at differing ADR levels (quintiles; averages 15.3-38.7%), with colonoscopy performance assumptions estimated from community-based data on physician ADRs and patients' post-colonoscopy risk of cancer. For patients receiving FIT screening with follow-up colonoscopy by physicians from the highest ADR quintile, simulated lifetime cancer incidence and mortality were 28.8 and 5.4 per 1,000, respectively, vs. 20.6 and 4.4 for primary colonoscopy screening (risk ratios, RR = 1.40; 95% probability interval (PI), 1.19-1.71 for incidence, and RR = 1.22; 95%PI, 1.02-1.54 for mortality). With every 5% point ADR decrease, lifetime cancer incidence was predicted to increase on average 9.0% for FIT vs. 12.3% for colonoscopy, and mortality increased 9.9% vs. 13.3%. In ADR quintile 1, simulated mortality was lower for FIT than colonoscopy screening (10.1 vs. 11.8; RR = 0.85; 95%PI, 0.83-0.90), while incidences were more similar. This suggests that relative cancer incidence and mortality reductions for FIT vs. colonoscopy screening may differ by ADR, with fewer predicted deaths with colonoscopy screening in higher ADR settings and fewer deaths with annual FIT screening in lower ADR settings.

The Effect of Right Colon Retroflexion on Adenoma Detection: A Systematic Review and Meta-analysis

BACKGROUND

Although colonoscopy with polypectomy can prevent up to 80% of colorectal cancers, a significant adenoma miss rate still exists, particularly in the right colon. Previous studies addressing right colon retroflexion have revealed discordant evidence regarding the benefit of this maneuver on adenoma detection with concomitant concerns about safety and rates of maneuver success. In this meta-analysis, we sought to determine the effect of right colon retroflexion on improving adenoma detection compared with conventional colonoscopy without retroflexion, as well as determine the rates of retroflexion maneuver success and adverse events.

METHODS

Multiple databases including MEDLINE, Embase, and Web of Science were searched for studies on right colon retroflexion and its impact on adenoma detection compared with conventional colonoscopy. Pooled analyses of adenoma detection and retroflexion success were based on mixed-effects and random-effects models with heterogeneity analyses.

RESULTS

Eight studies met the inclusion criteria (N=3660). The primary analysis comparing colonoscopy with right-sided retroflexion versus conventional colonoscopy to determine the per-adenoma miss rate in the right colon was 16.9% (95% confidence interval, 12.5%-22.5%). The overall rate of successful retroflexion was 91.9% (95% confidence interval, 86%-95%) and rate of adverse events was 0.03%.

CONCLUSIONS

Colonoscopy with right-sided retroflexion significantly increases the detection of adenomas in the right colon compared with conventional colonoscopy with a high rate of maneuver success and small risk of adverse events. Thus, reexamination of the right colon in retroflexed view should be strongly considered in future standard of care colonoscopy guidelines for quality improvement in colon cancer prevention.

Quality measures in gastrointestinal endoscopy: the current state

PURPOSE OF REVIEW

The purpose of this review is to summarize the current state of endoscopic quality measurement and use of measures in enhancing the value of endoscopic services.

RECENT FINDINGS

Initially, quality measurement of endoscopic procedures was claims based or included small unit or practice-specific efforts. Now we have a mature national registry and large electronic medical or procedural records that are designed to yield valuable data relevant to quality measurement.

SUMMARY

With the advent of better measures, we are beginning to understand that initial process and surrogate outcome measures (adenoma detection rate) can be improved to provide a better reflection of endoscopic quality. Importantly, however, even measures currently in use relate to important patient outcomes such as missed colon cancers. At a federal level, older cumbersome pay-for-performance initiatives have been combined into a new overarching program named the quality payment program within the centers for medicare and medicaid services. This program is an additional step toward furthering the progress from volume-to-value-based reimbursement. The legislation mandating the movement toward outcomes-linked (value) reimbursement is the medicare access and children's health insurance program reauthorization act, which was passed with overwhelming bipartisan support and will not be walked back by alterations of the affordable care act. Increasing portions of medicare reimbursement (and likely commercial to follow) will be linked to quality metrics, so familiarity with the underlying process and rationale will be important for all proceduralists.

Increased Rate of Adenoma Detection Associates With Reduced Risk of Colorectal Cancer and Death

BACKGROUND & AIMS

The quality of endoscopists' colonoscopy performance is measured by adenoma detection rate (ADR). Although ADR is associated inversely with interval colorectal cancer and colorectal cancer death, the effects of an increasing ADR have not been shown. We investigated whether increasing ADRs from individual endoscopists is associated with reduced risks of interval colorectal cancer and subsequent death.

METHODS

We performed a prospective cohort study of individuals who underwent a screening colonoscopy within the National Colorectal Cancer Screening Program in Poland, from January 1, 2004, through December 31, 2008. We collected data from 146,860 colonoscopies performed by 294 endoscopists, with each endoscopist having participated at least twice in annual editions of primary colonoscopy screening. We used annual feedback and quality benchmark indicators to improve colonoscopy performance. We used ADR quintiles in the whole data set to categorize the annual ADRs for each endoscopist. An increased ADR was defined as an increase by at least 1 quintile category, or the maintenance of the highest category in subsequent screening years. Multivariate frailty models were used to evaluate the effects of increased ADR on the risk of interval colorectal cancer and death.

RESULTS

Throughout the enrollment period, 219 endoscopists (74.5%) increased their annual ADR category. During 895,916 person-years of follow-up evaluation through the National Cancer Registry, we identified 168 interval colorectal cancers and 44 interval cancer deaths. An increased ADR was associated with an adjusted hazard ratio for interval colorectal cancer of 0.63 (95% confidence interval [CI], 0.45-0.88; P = .006), and for cancer death of 0.50 (95% CI, 0.27-0.95; P = .035). Compared with no increase in ADR, reaching or maintaining the highest quintile ADR category (such as an ADR > 24.56%) decreased the adjusted hazard ratios for interval colorectal cancer to 0.27 (95% CI, 0.12-0.63; P = .003), and 0.18 (95% CI, 0.06-0.56; P = .003), respectively.

CONCLUSIONS

In a prospective study of individuals who underwent screening colonoscopy within a National Colorectal Cancer Screening Program, we associated increased ADR with a reduced risk of interval colorectal cancer and death.

Impact of feedback and monitoring on colonoscopy withdrawal times and polyp detection rates

Background

Previous studies have shown colonoscopy withdrawal time (WT) to be a reliable surrogate indicator for polyp detection rate (PDR) and adenoma detection rate (ADR) in colonoscopy. Our aim was to assess the impact of feedback and monitoring of WT on PDR in routine colonoscopies with long-term follow-up.

Materials and methods

A total of 307 colonoscopies were performed in three separate clinical scenarios. First, PDR and WT were recorded without the staff being aware of the specific objective of the study. Before the second scenario, the staff was given interventional information and feedback on WTs and PDRs from the first scenario and was encouraged to aim for a minimum WT of 8 min. Retention of knowledge gained was reassessed in the third scenario 1 year later.

Results

The PDR in the first two scenarios differed significantly (p<0.01), with a more than 90% increase in PDR after intervention from 22% to 42% (95% CI 1.44 to 4.95), although the mean WT did not change (6.8 vs 7.2 min; p>0.05). The increase in PDR between the first and second scenarios was retained in the third follow-up scenario 1 year later where the WT of both polyp-positive and polyp-negative colonoscopies was found to be longer.

Conclusions

PDR almost doubled from the first to the second scenario of a real-life colonoscopy setting, indicating that awareness of WT is crucial. The knowledge gained from this intervention in routine practice was even retained after a year.