Assessment of the multiple components of the variability in the adenoma detection rate in sigmoidoscopy screening, and lessons for training

The impact of endoscopist performance and patient factors on distal adenoma detection and colorectal cancer incidence

BACKGROUND

High quality endoscopy is key for detecting and removing precursor lesions to colorectal cancer (CRC). Adenoma detection rates (ADRs) measure endoscopist performance. Improving other components of examinations could increase adenoma detection.

AIMS

To investigate how endoscopist performance at flexible sigmoidoscopy (FS) affects adenoma detection and CRC incidence.

METHODS

Among 34,139 participants receiving FS screening by the main endoscopist at one of 13 centres in the UK FS Screening Trial, median follow-up was 17 years. Factors examined included family history of CRC, bowel preparation quality, insertion and withdrawal time, bowel segment reached, patient pain and ADR. Odds ratios (OR) for distal adenoma detection were estimated by logistic regression. Hazard ratios (HR) for distal CRC incidence were estimated by Cox regression.

RESULTS

At screening, 4,104 participants had distal adenomas detected and 168 participants developed distal CRC during follow-up. In multivariable models, a family history of CRC (yes vs. no: OR 1.40, 95%CI 1.21-1.62), good or adequate bowel preparation quality (vs. excellent: OR 0.84, 95%CI 0.74-0.95; OR 0.56, 95%CI 0.49-0.65, respectively) and longer insertion and withdrawal times (≥ 4.00 vs. < 2.00 min: OR 1.96, 95%CI 1.68-2.29; OR 32.79, 95%CI 28.22-38.11, respectively) were associated with adenoma detection. Being screened by endoscopists with low or intermediate ADRs, compared to high ADRs, was positively associated with CRC incidence (multivariable: HR 4.71, 95%CI 2.65-8.38; HR 2.16, 95%CI 1.22-3.81, respectively).

CONCLUSIONS

Bowel preparation quality and longer insertion and withdrawal time are key for improving distal adenoma detection. Higher ADRs were associated with a lower risk of distal CRC.

Peer evaluation and feedback for invasive medical procedures: a systematic review

BACKGROUND

There is significant variability in the performance and outcomes of invasive medical procedures such as percutaneous coronary intervention, endoscopy, and bronchoscopy. Peer evaluation is a common mechanism for assessment of clinician performance and care quality, and may be ideally suited for the evaluation of medical procedures. We therefore sought to perform a systematic review to identify and characterize peer evaluation tools for practicing clinicians, assess evidence supporting the validity of peer evaluation, and describe best practices of peer evaluation programs across multiple invasive medical procedures.

METHODS

A systematic search of Medline and Embase (through September 7, 2021) was conducted to identify studies of peer evaluation and feedback relating to procedures in the field of internal medicine and related subspecialties. The methodological quality of the studies was assessed. Data were extracted on peer evaluation methods, feedback structures, and the validity and reproducibility of peer evaluations, including inter-observer agreement and associations with other quality measures when available.

RESULTS

Of 2,135 retrieved references, 32 studies met inclusion criteria. Of these, 21 were from the field of gastroenterology, 5 from cardiology, 3 from pulmonology, and 3 from interventional radiology. Overall, 22 studies described the development or testing of peer scoring systems and 18 reported inter-observer agreement, which was good or excellent in all but 2 studies. Only 4 studies, all from gastroenterology, tested the association of scoring systems with other quality measures, and no studies tested the impact of peer evaluation on patient outcomes. Best practices included standardized scoring systems, prospective criteria for case selection, and collaborative and non-judgmental review.

CONCLUSIONS

Peer evaluation of invasive medical procedures is feasible and generally demonstrates good or excellent inter-observer agreement when performed with structured tools. Our review identifies common elements of successful interventions across specialties. However, there is limited evidence that peer-evaluated performance is linked to other quality measures or that feedback to clinicians improves patient care or outcomes. Additional research is needed to develop and test peer evaluation and feedback interventions.

Water immersion sigmoidoscopy versus standard insufflation for colorectal cancer screening: A cohort study

BACKGROUND

Although the efficacy of water-assisted colonoscopy is well established, the role of water immersion sigmoidoscopy (WIS) remains unclear. We compared WIS with carbon dioxide insufflation sigmoidoscopy (CO₂S) on patient outcomes.

METHODS

We conducted an analysis of prospectively collected data from a single-center quality improvement program about patients undergoing unsedated screening sigmoidoscopy (WIS and CO₂S) between May 2019 and January 2020. Outcomes studied included the following: Rates of severe pain <17% (score of ≥7 on a numeric rating scale of 0-10, and on a Likert scale), willingness to repeat the procedure without sedation, adequate bowel cleanliness >75% (proportion of Boston Bowel Preparation Scale score: 2-3) and adenoma detection rate (ADR).

RESULTS

In total, 234 patients (111 WIS; 123 CO₂S) were included. All patients were aged 58 years and 58.9% were female; baseline characteristics were comparable between groups. There were no significant differences in rates of severe pain (WIS: 16.5%, CO₂S: 13.8%; P = 0.586), willingness to repeat the unsedated procedure (WIS: 82.3%, CO₂S: 84.5%; P = 0.713), adequate bowel cleanliness (WIS: 78.4%, CO₂S: 78%, P = 0.999) or ADR (WIS: 25.2%, CO₂S: 16.3%; P = 0.106) between groups. However, average procedure times were longer with WIS (9.06 min) compared to CO₂S (6.45 min; P < 0.001). Overall, 29.6% of women reported that they would repeat sigmoidoscopy only if sedated.

CONCLUSIONS

WIS does not ameliorate tolerance to and quality of sigmoidoscopy screening measured by several scores. When offered a choice, the women's willingness to repeat WIS or CO₂S without sedation was poor and raises concern on the opportunity of screening sigmoidoscopy without sedation in these subjects.

Factors affecting adenoma detection rate in a national flexible sigmoidoscopy screening programme: a retrospective analysis

BACKGROUND

A national colorectal cancer screening programme started in England in 2013, offering one-off flexible sigmoidoscopy to all men and women aged 55 years in addition to the biennial faecal occult blood testing programme offered to all individuals aged 60-74 years. We analysed data from six pilot flexible sigmoidoscopy screening centres to examine factors affecting the adenoma detection rate (ADR).

METHODS

We did a retrospective analysis of flexible sigmoidoscopy screening procedures performed in individuals aged 55 years at six pilot sites in England as part of the National Health Service Bowel Scope Screening programme. ADR (number of procedures in which at least one adenoma was removed or biopsied, divided by total number of procedures) was calculated for each site and each endoscopist. Multiple regression models were used to examine the variation in ADR with withdrawal time and extent of examination, and the effect of other factors including comfort and bowel preparation on extent of examination.

FINDINGS

The analysis included 8256 procedures done between May 7, 2013, and May 6, 2014. The overall ADR was 9·1% (95% CI 8·5-9·8; 755 of 8256 procedures), varying from 7·4% (6·2-8·9) to 11·0% (9·1-13·4) by screening centre. The ADR was 11·5% (95% CI 10·6-12·5; 493 of 4299 procedures) in men and 6·6% (5·9-7·4; 262 of 3957 procedures) in women (p<0·0001). On multivariate analysis, factors associated with adenoma detection were male sex (relative risk 1·69, 95% CI 1·46-1·95; p<0·0001) and a withdrawal time from the splenic flexure of at least 3·25 min in negative procedures (1·22, 1·00-1·48; p=0·045). However, increasing the withdrawal time to 4·0 min or more did not increase the likelihood of adenoma detection (1·22, 0·99-1·51; p=0·057). Procedures not reaching the splenic flexure were associated with lower chance of adenoma detection (eg, 0·77, 0·66-0·91; p=0·0015 for procedures reaching the descending colon), but there was no additional benefit associated with reaching the transverse colon (0·83, 0·67-1·02; p=0·069). Women (0·83, 0·80-0·87; p<0·0001), individuals with adequate (0·79, 0·76-0·83; p<0·0001) or poor (0·58, 0·51-0·67; p<0·0001) bowel preparation (compared with good bowel preparation), and those with mild (0·82, 0·76-0·88; p<0·0001) or moderate or severe (0·58, 0·51-0·66; p<0·0001) discomfort (compared with no discomfort) were less likely to have a procedure reaching the splenic flexure.

INTERPRETATION

Key performance indicators for flexible sigmoidoscopy screening should be defined, including standards for insertion and withdrawal times, optimal depth, and bowel preparation. ADR could be improved by recommending a withdrawal time from the splenic flexure of at least 3·25 min (ideally 3·5-4·0 min).

FUNDING

None.

Quality indicators in digestive endoscopy: introduction to structure, process, and outcome common indicators

The general goal of the project wherein this paper is framed is the proposal of useful quality and safety procedures and indicators to facilitate quality improvement in digestive endoscopy units. This initial offspring sets forth procedures and indicators common to all digestive endoscopy procedures. First, a diagram of pre- and post-digestive endoscopy steps was developed. A group of health care quality and/or endoscopy experts under the auspices of the Sociedad Española de Patología Digestiva (Spanish Society of Digestive Diseases) carried out a qualitative review of the literature regarding the search for quality indicators in endoscopic procedures. Then, a paired analysis was used for the selection of literature references and their subsequent review. Twenty indicators were identified, including seven for structure, eleven for process (five pre-procedure, three intra-procedure, three post-procedure), and two for outcome. Quality of evidence was analyzed for each indicator using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) classification.

Patient- and procedure-related factors affecting proximal and distal detection rates for polyps and adenomas: results from 1603 screening colonoscopies

BACKGROUND

Screening colonoscopy is less effective in reducing the incidence of proximal compared to distal colorectal cancer, presumably because of missed adenomas and advanced lesions during endoscopy. Thus, effectiveness and success of colorectal cancer (CRC) screening programs depend decisively on the quality of the endoscopic procedures.

METHODS

A retrospective analysis of 1603 average risk screening colonoscopies to calculate and to identify determinants of separate detection rates for proximally and distally located polyps, adenomas, and advanced adenomas was performed.

RESULTS

56.1 % of 1603 individuals included were men, and the mean age was 60.2 ± 10.2 years. Distal detection rates were markedly higher compared to proximal detection rates for polyps (40.9 vs. 23.8 %), adenomas (21.3 vs. 16.2 %), and advanced adenomas (4.0 vs. 2.0 %). A gradual increase in detection rates with increasing age was found for proximal and distal localization. Gender difference was also seen for polyps and adenomas, but not for advanced adenomas. In multivariate analysis, age <65.0 years and female gender were independently associated with a lower separate polyp detection rate (PDR) and adenoma detection rate (ADR). The use of propofol was the only procedure-related variable significantly associated with higher polyp detection rate.

CONCLUSION

Since age and gender affect detection rates of proximally and distally located polyps and adenomas, the requirement of a specific gender-related limit in total detection rates may be insufficient as a quality indicator for screening colonoscopies.

Meticulous cecal image documentation at colonoscopy is associated with improved polyp detection

BACKGROUND AND STUDY AIMS

No studies have looked at the quality of cecal images versus the outcomes of colonoscopic procedures. Here, we tested our hypothesis that endoscopists who provide better image documentation of the cecum during their procedures have a higher polyp detection rate (PDR).

PATIENTS AND METHODS

In this retrospective study, planned colonoscopies performed by 16 experienced colonoscopists were included. We formulated a new scoring system, the cecal image documentation score (CIDS), for quantifying the quality of the cecal images obtained at colonoscopy. Cecal image documentation was graded as follows: no image, 0; unclear image, 1; clear image, 2; clear image with a label, 3. We assessed the correlation between image quality and the PDR.

RESULTS

A total of 651 procedures performed by 16 colonoscopists were analyzed retrospectively. The mean CIDS for the 16 endoscopists was 2.13. The mean PDR was 23.5 %, and the mean polyps per procedure value (PPP) was 0.42. The 10 colonoscopists with a mean CIDS > 2.0 (n = 429 procedures) had a PDR of 27.8 % and a PPP of 0.51. On the other hand, the 6 colonoscopists (n = 222 procedures) with a mean CIDS < 2.0 had a PDR of 15.2 % and a PPP of 0.23. A mean CIDS > 2.0 was associated with a higher PDR (odds ratio [OR] 2.1, 95 % confidence interval [CI] 1.4 - 3.2, P = 0.001). A mean CIDS > 2.0 was found to be an independent predictor of a higher PDR (OR 2.53, 95 %CI 1.45 - 3.59, P = 0.001). A mean CIDS > 2.0 was also associated with a higher right-sided PDR (OR 3.67, 95 %CI 1.91 - 7.02, P < 0.001).

CONCLUSIONS

Colonoscopists who are more meticulous in cecal image documentation detect more polyps per procedure and have higher PDRs. Better cecal image documentation is also associated with better right-sided colonic polyp detection.

Systematic review and meta-analysis of the evidence for flexible sigmoidoscopy as a screening method for the prevention of colorectal cancer

BACKGROUND

Colorectal cancer is a significant cause of death. Removal of precancerous adenomas, and early detection and treatment of cancer, has been shown to reduce the risk of death. The aim of this review and meta-analysis was to determine whether flexible sigmoidoscopy (FS) is an effective population screening method for reducing mortality from colorectal cancer.

METHODS

MEDLINE (1946 to December 2012) and Embase (1980-2012, week 15) were searched for randomized clinical trials in which FS was used to screen non-symptomatic adults from a general population, and FS was compared with either no screening or any other alternative screening methods. Meta-analysis was carried out using a random-effects Mantel-Haenzsel model.

RESULTS

Twenty-four papers met the inclusion criteria, reporting results from 14 trials. Uptake of FS was usually lower than that for stool-based tests, although FS was more effective at detecting advanced adenoma and carcinoma. FS reduced the incidence of colorectal cancer after screening, and long-term mortality from colorectal cancer, compared with no screening in a selected population. Compared with stool-based tests in a general population, FS was associated with fewer interval cancers.

CONCLUSION

FS is efficacious at reducing colorectal cancer mortality compared with no screening. It is more effective at detecting advanced adenoma and carcinoma than stool-based tests. FS may be compromised by poorer uptake. Introduction of FS as a screening method should be done on a pilot basis in populations in which it is not currently used, and close attention should be paid to maximizing uptake. The relative risk of adverse events with FS compared with stool-based tests should be quantified, and its real-world effectiveness evaluated against the most effective stool-based tests.

Concerns and challenges in flexible sigmoidoscopy screening

In 1992, two well-conducted case-control studies used data from two different health maintenance organizations and demonstrated a 59-79% reduction in mortality from colorectal cancer (CRC) following exposure to sigmoidoscopy. These studies highlight the possibility of reducing mortality from CRC using population-based endoscopic screening. The development of fiber optics improved the technology, and the ease of performing flexible sigmoidoscopy (FS) with widespread adoption of this screening modality. To date, FS is the only endoscopic screening modality that has been shown to reduce mortality in randomized clinical trials. This article reviews the development of sigmoidoscopy, its use in CRC screening and the current reduced role of this proven screening modality, and explores new frontiers for population-based FS screening.

Progress and challenges in colorectal cancer screening. Gastroenterol Res Pract. 2012;2012:846985. [PMID: 22548053 PMCID: PMC3324920 DOI: 10.1155/2012/846985]

Although faecal and endoscopic tests appear to be effective in reducing colorectal cancer incidence and mortality, further technological and organizational advances are expected to improve the performance and acceptability of these tests. Several attempts to improve endoscopic technology have been made in order to improve the detection rate of neoplasia, especially in the proximal colon. Based on the latest evidence on the long-term efficacy of screening tests, new strategies including endoscopic and faecal modalities have also been proposed in order to improve participation and the diagnostic yield of programmatic screening. Overall, several factors in terms of both efficacy and costs of screening strategies, including the high cost of biological therapy for advanced colorectal cancer, are likely to affect the cost-effectiveness of CRC screening in the future.

Screening for colorectal cancer: possible improvements by risk assessment evaluation?

Emerging results indicate that screening improves survival of patients with colorectal cancer. Therefore, screening programs are already implemented or are being considered for implementation in Asia, Europe and North America. At present, a great variety of screening methods are available including colono- and sigmoidoscopy, CT- and MR-colonography, capsule endoscopy, DNA and occult blood in feces, and so on. The pros and cons of the various tests, including economic issues, are debated. Although a plethora of evaluated and validated tests even with high specificities and reasonable sensitivities are available, an international consensus on screening procedures is still not established. The rather limited compliance in present screening procedures is a significant drawback. Furthermore, some of the procedures are costly and, therefore, selection methods for these procedures are needed. Current research into improvements of screening for colorectal cancer includes blood-based biological markers, such as proteins, DNA and RNA in combination with various demographically and clinically parameters into a "risk assessment evaluation" (RAE) test. It is assumed that such a test may lead to higher acceptance among the screening populations, and thereby improve the compliances. Furthermore, the involvement of the media, including social media, may add even more individuals to the screening programs. Implementation of validated RAE and progressively improved screening methods may reform the cost/benefit of screening procedures for colorectal cancer. Therefore, results of present research, validating RAE tests, are awaited with interest.

Colorectal cancer screening

Colorectal cancer (CRC) is the third most common cause of cancer death worldwide and a major health problem. In this review, the different approaches for CRC screening will be outlined with emphasis on evidence-based medicine. Evidence from randomized trials on the effectiveness of CRC screening is summarized. Several screening tools for CRC are available. They can be categorized according to their mode of action: early detection tools such as the faecal occult blood test (FOBT) and cancer prevention tools such as flexible sigmoidoscopy and colonoscopy. Meta-analyses of randomized trials show that FOBT screening reduces CRC mortality by 16% (risk ratio 0.84; 95% confidence interval (CI) 0.78-0.9) compared with 30% (risk ratio 0.7; 95% CI 0.6-0.81) for flexible sigmoidoscopy screening. FOBT screening is cheap and noninvasive, but results in large numbers of false-positive tests and needs to be repeated frequently. Flexible sigmoidoscopy is more invasive, but is effective for once-only screening. Although colonoscopy screening is used in some countries, no randomized trials have been conducted to estimate its benefit, and therefore, it should not be recommended at the present time. Faecal occult blood test and flexible sigmoidoscopy are the two CRC screening tools that can be recommended as they have been proven to reduce CRC mortality. Colonoscopy has the potential to be superior to FOBT and flexible sigmoidoscopy, but needs to be evaluated in randomized trials before any recommendation can be provided.

Neoplasia detection rates after positive fecal occult blood test results are not affected by endoscopy center: a population-based study

BACKGROUND

We previously showed a significant variability in adenoma detection among colonoscopists who were participating in a mass screening program. The reasons for such variability remain largely unknown.

OBJECTIVE

To study intercenter variations in neoplasia detection.

DESIGN AND SETTING

Secondary analyses of colonoscopy findings from the 2 first rounds of a French screening program: logistic regressions and repeated-measures analyses of variance.

MATERIAL

A total of 3487 colonoscopies performed by all 19 endoscopists who performed 30 examinations or more per round at 8 centers (6 private, 2 public).

MAIN OUTCOME MEASUREMENTS

Probabilities of detecting 1, 2, or 3 or more adenomas, 1 adenoma 10 mm or larger, or colorectal cancer, as well as the corresponding adjusted (for patient age and sex) per-center detection rates.

RESULTS

Endoscopy centers were not significant predictors of the probability of detecting any category of neoplasia with the exception of the 2 adenomas or more category (P < .005). The ranges of the adjusted detection rates for each of these categories were 33.1% to 43.1%, 11.1% to 21.6%, 3.6% to 8.1%, 16.3% to 23.6%, and 8.3% to 12.6%, respectively. When the colonoscopies that were performed by the 11 endoscopists who performed 30 examinations or more per center in 2 or more centers were separately analyzed, no intercenter statistically significant variability was observed with the exception of 1 endoscopist and the 1 adenoma category. In a subgroup of 1100 colonoscopies performed by 6 endoscopists who were working at the same 3 centers, intercenter variability was not statistically significant.

LIMITATIONS

Type II error because of sample sizes.

CONCLUSIONS

In our setting, intercenter variability did not explain interendoscopist variability for neoplasia detection rate.

Evidence for colorectal cancer screening

The incidence of colorectal cancer (CRC) has been increasing during the past decades, and the lifetime risk for CRC in industrialised countries is about 5%. CRC is a good candidate for screening, because it is a disease with high prevalence, has recognised precursors, and early treatment is beneficial. This paper outlines the evidence for efficacy from randomised trials for the most commonly used CRC screening tests to reduce CRC incidence and mortality in the average-risk population. Four randomised trials have investigated the effect of guaiac-based fecal occult blood screening on CRC mortality, with a combined CRC mortality risk reduction of 15-17% in an intention-to-screen analysis, and 25% for those people who attended screening. Flexible sigmoidoscopy screening has been evaluated in three randomised trials. The observed reduction in CRC incidence varied between 23 and 80%, and between 27 and 67% for CRC mortality, respectively (intention-to-screen analyses) in the trials with long follow-up time. No randomised trials exist in other CRC screening tools, included colonoscopy screening. FOBT and flexible sigmoidoscopy are the two CRC screening methods which have been tested in randomised trials and shown to reduce CRC mortality. These tests can be recommended for CRC screening.