Adenoma characteristics in the English Bowel Cancer Screening Programme.

AIM: The English Bowel Cancer Screening Programme detects colorectal cancers and premalignant polyps in a faecal occult blood test-positive population. The aim of this work is to describe the detection rates and characteristics of adenomas within the programme, identify predictive factors influencing the presence or absence of carcinoma within adenomas and identify the factors predicting the presence of advanced colonic neoplasia in different colon segments. METHOD: The Bowel Cancer Screening System was retrospectively searched for polyps detected during colonoscopies between June 2006 and June 2012, at which time a guaiac test was being used. Data on size, location and histological features were collected, and described. Univariate and multivariate analyses were used to determine the significant factors influencing the development of carcinoma within an adenoma. RESULTS: A total of 229 419 polyps were identified; after exclusions 136 973 adenomas from 58 334 patients were evaluated. Over half were in the rectum or sigmoid colon. Subcentimetre adenomas accounted for 69.8% of the total. The proportion of adenomas containing advanced histological features increased with increasing adenoma size up to 35 mm, then plateaued. A focus of carcinoma was found in 2282 (1.7%) adenomas, of which 95.6% were located distally. Carcinoma was identified even in diminutive adenomas (0.1%). The proportion of adenomas containing cancer was significantly higher in women than men (2.0% vs. 1.5%, p < 0.001). CONCLUSION: This national, prospectively captured dataset adds robust information about histological features of adenomas that convey an increased risk for colorectal cancer, and identifies caecal adenomas, high-grade dysplasia, increasing adenoma size, distal location and female sex as independent risk factors associated with carcinoma.

Colorectal polyp outcomes after participation in the seAFOod polyp prevention trial: Evidence of rebound elevated colorectal polyp risk after short-term aspirin use.

BACKGROUND: The seAFOod polyp prevention trial was a randomised, placebo-controlled, 2 × 2 factorial trial of aspirin 300 mg and eicosapentaenoic acid (EPA) 2000 mg daily in individuals who had a screening colonoscopy in the English Bowel Cancer Screening Programme (BCSP). Aspirin treatment was associated with a 20% reduction in colorectal polyp number at BCSP surveillance colonoscopy 12 months later. It is unclear what happens to colorectal polyp risk after short-term aspirin use. AIM: To investigate colorectal polyp risk according to the original trial treatment allocation, up to 6 years after trial participation. METHODS: All seAFOod trial participants were scheduled for further BCSP surveillance and provided informed consent for the collection of colonoscopy outcomes. We linked BCSP colonoscopy data to trial outcomes data. RESULTS: In total, 507 individuals underwent one or more colonoscopies after trial participation. Individuals grouped by treatment allocation were well matched for clinical characteristics, follow-up duration and number of surveillance colonoscopies. The polyp detection rate (PDR; the number of individuals who had ≥1 colorectal polyp detected) after randomization to placebo aspirin was 71.1%. The PDR was 80.1% for individuals who had received aspirin (odds ratio [OR] 1.13 [95% confidence interval 1.02, 1.24]; p = 0.02). There was no difference in colorectal polyp outcomes between individuals who had been allocated to EPA compared with its placebo (OR for PDR 1.00 [0.91, 1.10]; p = 0.92). CONCLUSION: Individuals who received aspirin in the seAFOod trial demonstrated increased colorectal polyp risk during post-trial surveillance. Rebound elevated neoplastic risk after short-term aspirin use has important implications for aspirin cessation driven by age-related bleeding risk. ISRCTN05926847.

Colorectal cancer and advanced adenoma incidence during post-polypectomy surveillance: a national cohort study in the English Bowel Cancer Screening Programme.

BACKGROUND: Improved colonoscopy quality has led to debate about whether all post-polypectomy surveillance is justified. We evaluated surveillance within the English Bowel Cancer Screening Programme (BCSP) to determine the yield of surveillance and identify predictive factors for surveillance outcome. METHODS: We performed a retrospective cohort study of individuals undergoing post-polypectomy surveillance between July 2006 and January 2017. BCSP records were linked to the National Cancer Registration Database to identify interval-type post-colonoscopy colorectal cancers (CRCs). Advanced adenoma and CRC at surveillance were documented. CRC incidence was compared with the general population using standardized incidence ratios (SIRs). Predictors of advanced adenomas at first surveillance (S1), and CRC during follow-up, were identified. RESULTS: 44 151 individuals (23 078 intermediate risk; 21 073 high risk) underwent 64 544 surveillance episodes. Advanced adenoma and CRC yields were, respectively, 10.0 % and 0.5 % at S1, 8.5 % and 0.4 % at S2, and 10.8 % and 0.4 % at S3. S1 yield was lowest in those with one index adenoma ≥ 10 mm (advanced adenoma 6.1 %; CRC 0.3 %). The SIR was 0.76 (95 %CI 0.66-0.88), accounted for by the intermediate risk group (intermediate risk SIR 0.61, 95 %CI 0.49-0.75; high risk SIR 0.95, 95 %CI 0.79-1.15). Adenoma multiplicity, presence of a large nonpedunculated adenoma, and greater villous component were associated with advanced adenoma at S1. Older age and multiplicity were significantly associated with CRC risk. CONCLUSION: This large, national analysis found low levels of CRC in those undergoing surveillance and low advanced adenoma yield in most subgroups. Less intensive surveillance in some subgroups is warranted, and surveillance may be avoided in those with a single large adenoma.

Heterogeneity in colorectal cancer incidence among people recommended 3-yearly surveillance post-polypectomy: a validation study.

BACKGROUND: Colonoscopy surveillance is recommended for patients at increased risk of colorectal cancer (CRC) following adenoma removal. Low-, intermediate-, and high-risk groups are defined by baseline adenoma characteristics. We previously examined intermediate-risk patients from hospital data and identified a higher-risk subgroup who benefited from surveillance and a lower-risk subgroup who may not require surveillance. This study explored whether these findings apply in individuals undergoing CRC screening. METHODS: This retrospective study used data from the UK Flexible Sigmoidoscopy Screening Trial (UKFSST), English CRC screening pilot (ECP), and US Kaiser Permanente CRC prevention program (KPCP). Screening participants (50 - 74 years) classified as intermediate-risk at baseline colonoscopy were included. CRC data were available through 2006 (KPCP) or 2014 (UKFSST, ECP). Lower- and higher-risk subgroups were defined using our previously identified baseline risk factors: higher-risk participants had incomplete colonoscopies, poor bowel preparation, adenomas ≥ 20 mm or with high-grade dysplasia, or proximal polyps. We compared CRC incidence in these subgroups and in the presence vs. absence of surveillance using Cox regression. RESULTS: Of 2291 intermediate-risk participants, 45 % were classified as higher risk. Median follow-up was 11.8 years. CRC incidence was higher in the higher-risk than lower-risk subgroup (hazard ratio [HR] 2.08, 95 % confidence interval [CI] 1.07 - 4.06). Surveillance reduced CRC incidence in higher-risk participants (HR 0.35, 95 %CI 0.14 - 0.86) but not statistically significantly so in lower-risk participants (HR 0.41, 95 %CI 0.12 - 1.38). CONCLUSION: As previously demonstrated for hospital patients, screening participants classified as intermediate risk comprised two risk subgroups. Surveillance clearly benefited the higher-risk subgroup.

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.

The association between long-term conditions and uptake of population-based screening for colorectal cancer: results from two English cohort studies.

INTRODUCTION: Uptake of screening for colorectal cancer (CRC) can reduce mortality, and population-based screening is offered in England. To date, there is little evidence on the association between having a long-term condition (LTC) and CRC screening uptake. The objective of this study was to examine the association between having an LTC and uptake of CRC screening in England with the guaiac fecal occult blood test, with a particular focus on common mental disorders. METHODS: The study was a preregistered secondary analysis of two cohorts: first, a linked data set between the regional Yorkshire Health Study (YHS) and the National Health Service National Bowel Cancer Screening Program (BCSP, years 2006-2014); second, the national English Longitudinal Study of Ageing (ELSA, years 2014-2015). Individuals eligible for BCSP screening who participated in either the YHS (7,142) or ELSA Wave 7 (4,099) were included. Study registration: ClinicalTrials.gov, number NCT02503969. RESULTS: In both the cohorts, diabetes was associated with lower uptake (YHS odds ratio [OR] for non-uptake 1.35, 95% CI 1.03-1.78; ELSA 1.33, 1.03-1.72) and osteoarthritis was associated with increased uptake (YHS 0.75, 0.57-0.99; ELSA 0.76, 0.62-0.93). After controlling for broader determinants of health, there was no evidence of significantly different uptake for individuals with common mental disorders. CONCLUSION: Two large independent cohorts provided evidence that uptake of CRC screening is lower among individuals with diabetes and higher among individuals with osteoarthritis. Further work should compare barriers and facilitators to screening among individuals with either of these conditions. This study also demonstrates the benefits of data linkage for improving clinical decision-making.

Colonoscopic perforations in the English National Health Service Bowel Cancer Screening Programme.

BACKGROUND: Perforation is the most serious adverse event associated with colonoscopy. In this study of data from the English National Health Service Bowel Cancer Screening Programme, we aimed to describe the presentation and management of perforations, and to determine factors associated with poorer outcomes post-perforation. METHODS: The medical records of patients with a perforation following the national screening colonoscopy were retrospectively examined. All colonoscopies performed from 02/08/2006 to 13/03/2014 were studied. Bowel Cancer Screening Centres across England were contacted and asked to complete a detailed dataset relating to perforation presentation, management, and outcome. RESULTS: 263 129 colonoscopies were analyzed, and the rate of perforation was 0.06 %. Complete data were reviewed for 117 perforations: 70.1 % of perforations (82/117) occurred during therapeutic colonoscopies; 54.9 % (62/113) of patients with perforations who were admitted to hospital and in whom data were complete underwent surgery; 26.1 % (30/115) of hospitalized patients left the hospital with a stoma and 19.1 % (22/115) developed post-perforation morbidity. Perforations not detected during colonoscopy were significantly more likely to require surgery (P = 0.03). Diagnostic perforations were significantly more likely to require surgery (P = 0.002) and were associated with higher rates of post-perforation morbidity (P = 0.01). At presentation, the presence of abdominal pain (P = 0.01), a pulse rate > 100 beats per minute (P = 0.049), and a respiratory rate > 20 breaths per minute (P = 0.01) were significantly associated with the patient having surgery. CONCLUSIONS: This is the largest retrospective observational case series in Europe to describe post-perforation presentation, management, and outcomes. We have confirmed that perforation leads to surgical intervention, stoma formation, and post-perforation morbidity. Perforations not recognized during the colonoscopy were significantly more likely to require surgery. Diagnostic perforations were at greater risk of requiring surgery and developing post-perforation morbidity.

High test positivity and low positive predictive value for colorectal cancer of continued faecal occult blood test screening after negative colonoscopy.

Objectives The English Bowel Cancer Screening Programme offers biennial guaiac faecal occult blood test (gFOBT) screening to 60-74-year-olds. Participants with positive results are referred for follow-up, but many do not have significant findings. If they remain age eligible, these individuals are reinvited for gFOBT screening. We evaluated the performance of repeat screening in this group. Methods We analysed data on programme participants reinvited to gFOBT screening after either previous negative gFOBT ( n = 327,542), or positive gFOBT followed by a diagnostic investigation negative for colorectal cancer (CRC) or adenomas requiring surveillance ( n = 42,280). Outcomes calculated were uptake, test positivity, yield of CRC, and positive predictive value (PPV) of gFOBT for CRC. Results For participants with a previous negative gFOBT, uptake in the subsequent screening round was 87.5%, positivity was 1.3%, yield of CRC was 0.112% of those adequately screened, and the PPV of gFOBT for CRC was 9.1%. After a positive gFOBT and a negative diagnostic investigation, uptake in the repeat screening round was 82.6%, positivity was 11.3%, CRC yield was 0.172% of participants adequately screened, and the PPV of gFOBT for CRC was 1.7%. Conclusion With high positivity and low PPV for CRC, the suitability of routine repeat gFOBT screening in two years among individuals with a previous positive test and a negative diagnostic examination needs to be carefully considered.

Post-polypectomy bleeding in the English National Health Service Bowel Cancer Screening Programme.

Background and study aims Colonoscopic polypectomy reduces colorectal cancer incidence, but is associated with complications including post-polypectomy bleeding (PPB). PPB ranges in severity from minor to life-threatening, making interpretation and comparison difficult. No previous studies have examined PPB rate according to a standardized severity grading system. We aimed to determine the PPB rate stratified by severity grading, explore factors that contribute to PPB severity grading, and describe PPB management. Methods Data relating to PPB were prospectively collected from all colonoscopies performed in one region of the English NHS Bowel Cancer Screening Programme (BCSP) from 06/12/2010 to 15/07/2014. PPB was defined and stratified into major, intermediate, and minor according to BCSP standardized definitions based on the American Society for Gastrointestinal Endoscopy adverse events lexicon. Results A total of 15 285 colonoscopies (23 766 polypectomies) were analyzed. The PPB rate per colonoscopy was 0.44 % (95 % confidence interval [CI] 0.34 - 0.54) and the rate per polypectomy was 0.29 % (95 %CI 0.20 - 0.38); 2.9 % of PPBs were major and 42.6 % were intermediate. Repeat endoscopy occurred in 27.9 % and was the most common reason for bleeding being categorized as of intermediate severity, although therapy was applied in only 36.8 % of these cases. A therapeutic intervention was significantly more common in patients with PPB who had either a hemoglobin drop ≥ 2 g/dL and/or a blood transfusion (P = 0.04, relative risk 3.47, 95 %CI 1.05 - 11.52). Conclusions This study specifically examined colonoscopic PPB rate, stratified using standardized criteria. The rates of PPB were low, with the majority of PPB being of minor severity. Current stratification of PPB severity combines measures of bleed severity with interventions. Using only hemoglobin drop ≥ 2 g/dL and/or blood transfusion as markers of PPB severity may simplify stratification, and allow a better assessment of the necessity and impact of an intervention.

Patient experience of CT colonography and colonoscopy after fecal occult blood test in a national screening programme.

OBJECTIVE: To investigate patient experience of CT colonography (CTC) and colonoscopy in a national screening programme. METHODS: Retrospective analysis of patient experience postal questionnaires. We included screenees from a fecal occult blood test (FOBt) based screening programme, where CTC was performed when colonoscopy was incomplete or deemed unsuitable. We analyzed questionnaire responses concerning communication of test risks, test-related discomfort and post-test pain, as well as complications. CTC and colonoscopy responses were compared using multilevel logistic regression. RESULTS: Of 67,114 subjects identified, 52,805 (79 %) responded. Understanding of test risks was lower for CTC (1712/1970 = 86.9 %) than colonoscopy (48783/50975 = 95.7 %, p < 0.0001). Overall, a slightly greater proportion of screenees found CTC unexpectedly uncomfortable (506/1970 = 25.7 %) than colonoscopy (10,705/50,975 = 21.0 %, p < 0.0001). CTC was tolerated well as a completion procedure for failed colonoscopy (unexpected discomfort; CTC = 26.3 %: colonoscopy = 57.0 %, p < 0.001). Post-procedural pain was equally common (CTC: 288/1970,14.6 %, colonoscopy: 7544/50,975,14.8 %; p = 0.55). Adverse event rates were similar in both groups (CTC: 20/2947 = 1.2 %; colonoscopy: 683/64,312 = 1.1 %), but generally less serious with CTC. CONCLUSIONS: Even though CTC was reserved for individuals either unsuitable for or unable to complete colonoscopy, we found only small differences in test-related discomfort. CTC was well tolerated as a completion procedure and was extremely safe. CTC can be delivered across a national screening programme with high patient satisfaction. KEY POINTS: • High patient satisfaction at CTC is deliverable across a national screening programme. • Patients who cannot tolerate screening colonoscopy are likely to find CTC acceptable. • CTC is extremely safe; complications are rare and almost never serious. • Patients may require more detailed information regarding the expected discomfort of CTC.

Terminal digit preference biases polyp size measurements at endoscopy, computed tomographic colonography, and histopathology.

BACKGROUND AND STUDY AIMS: Terminal digit preference bias for "pleasing" numbers has been described in many areas of medicine. The aim of this study was to determine whether endoscopists, radiologists, and pathologists exhibit such bias when measuring colorectal polyp diameters. METHODS: Colorectal polyp diameters measured at endoscopy, computed tomographic colonography (CTC), and histopathology were collated from a colorectal cancer screening program and two parallel multicenter randomized trials. Smoothing models were fitted to the data to estimate the expected number of polyps at 1-mm increments, assuming no systematic measurement bias. The difference between the expected and observed numbers of polyps was calculated for each terminal digit using statistical modeling. The impact of measurement bias on per-patient detection rates of polyps ≥ 10 mm was estimated for each modality. RESULTS: A total of 92 124 individual polyps were measured by endoscopy (91 670 screening and 454 from trials), 2385 polyps were measured by CTC (1664 screening, 721 trials), and 79 272 were measured by histopathology (78 783 screening, 489 trials). Clustering of polyp diameter measurements at 5-mm intervals was demonstrated for all modalities, both in the screening program and the trials. The statistical models estimated that per-patient detection rates of polyps ≥ 10 mm were over-inflated by 2.4 % for endoscopy, 3.1 % for CTC, and 3.3 % for histopathology in the screening program, with similar trends in the randomized trials. CONCLUSION: Endoscopists, radiologists, and pathologists all exhibit terminal digit preference when measuring colorectal polyps. This will bias trial data, referral rates for further testing, adenoma surveillance regimens, and comparisons between tests.

Appearances of screen-detected versus symptomatic colorectal cancers at CT colonography.

OBJECTIVES: The aim of this study was to compare the morphology, radiological stage, conspicuity, and computer-assisted detection (CAD) characteristics of colorectal cancers (CRC) detected by computed tomographic colonography (CTC) in screening and symptomatic populations. METHODS: Two radiologists independently analyzed CTC images from 133 patients diagnosed with CRC in (a) two randomized trials of symptomatic patients (35 patients with 36 tumours) and (b) a screening program using fecal occult blood testing (FOBt; 98 patients with 100 tumours), measuring tumour length, volume, morphology, radiological stage, and subjective conspicuity. A commercial CAD package was applied to both datasets. We compared CTC characteristics between screening and symptomatic populations with multivariable regression. RESULTS: Screen-detected CRC were significantly smaller (mean 3.0 vs 4.3 cm, p < 0.001), of lower volume (median 9.1 vs 23.2 cm3, p < 0.001) and more frequently polypoid (34/100, 34 % vs. 5/36, 13.9 %, p = 0.02) than symptomatic CRC. They were of earlier stage than symptomatic tumours (OR = 0.17, 95 %CI 0.07-0.41, p < 0.001), and were judged as significantly less conspicuous (mean conspicuity 54.1/100 vs. 72.8/100, p < 0.001). CAD detection was significantly lower for screen-detected (77.4 %; 95 %CI 67.9-84.7 %) than symptomatic CRC (96.9 %; 95 %CI 83.8-99.4 %, p = 0.02). CONCLUSIONS: Screen-detected CRC are significantly smaller, more frequently polypoid, subjectively less conspicuous, and less likely to be identified by CAD than those in symptomatic patients. KEY POINTS: • Screen-detected colorectal cancers (CRC) are significantly smaller than symptomatic CRC. • Screening cases are significantly less conspicuous to radiologists than symptomatic tumours. • Screen-detected CRC have different morphology compared to symptomatic tumours (more polypoid, fewer annular). • A commercial computer-aided detection (CAD) system was significantly less likely to note screen-detected CRC.

Patients' experience of colonoscopy in the English Bowel Cancer Screening Programme.

BACKGROUND AND STUDY AIMS: Understanding patients' experience of screening programs is crucial for service improvement. The English Bowel Cancer Screening Programme (BCSP) aims to achieve this by sending out questionnaires to all patients who undergo a colonoscopy following an abnormal fecal occult blood test result. This study used the questionnaire data to report the experiences of these patients. PATIENTS AND METHODS: Data on patients who underwent colonoscopy between 2011 and 2012 were extracted from the BCSP database. Descriptive statistics were used to summarize key questionnaire items relating to informed choice, psychological wellbeing, physical experience, and after-effects. Multilevel logistic regression was used to test for associations with variables of interest: sex, age, socioeconomic status, colonoscopy results, and screening center performance (adenoma detection rate, cecal intubation rate, proportion of colonoscopies involving sedation). RESULTS: Data from 50,858 patients (79.3 % of those eligible) were analyzed. A majority reported a positive experience on items relating to informed choice (e. g. 95.7 % felt they understood the risks) and psychological wellbeing (e. g. 98.3 % felt they were treated with respect). However, an appreciable proportion experienced unexpected test discomfort (21.0 %) or pain at home (14.8 %). There were few notable demographic differences, although women were more likely than men to experience unexpected discomfort (25.1 % vs. 18.0 %; P < 0.01) and pain at home (18.2 % vs. 12.3 %; P < 0.01). No associations with center-level variables were apparent. CONCLUSIONS: Colonoscopy experience was generally positive, suggesting high satisfaction with the BCSP. Reported pain and unexpected discomfort were more negative than most other outcomes (particularly for women); measures to improve this should be considered.

Factors associated with completion of bowel cancer screening and the potential effects of simplifying the screening test algorithm.

BACKGROUND: The primary colorectal cancer screening test in England is a guaiac faecal occult blood test (gFOBt). The NHS Bowel Cancer Screening Programme (BCSP) interprets tests on six samples on up to three test kits to determine a definitive positive or negative result. However, the test algorithm fails to achieve a definitive result for a significant number of participants because they do not comply with the programme requirements. This study identifies factors associated with failed compliance and modifications to the screening algorithm that will improve the clinical effectiveness of the screening programme. METHODS: The BCSP Southern Hub data for screening episodes started in 2006-2012 were analysed for participants aged 60-69 years. The variables included age, sex, level of deprivation, gFOBt results and clinical outcome. RESULTS: The data set included 1,409,335 screening episodes; 95.08% of participants had a definitively normal result on kit 1 (no positive spots). Among participants asked to complete a second or third gFOBt, 5.10% and 4.65%, respectively, failed to return a valid kit. Among participants referred for follow up, 13.80% did not comply. Older age was associated with compliance at repeat testing, but non-compliance at follow up. Increasing levels of deprivation were associated with non-compliance at repeat testing and follow up. Modelling a reduction in the threshold for immediate referral led to a small increase in completion of the screening pathway. CONCLUSIONS: Reducing the number of positive spots required on the first gFOBt kit for referral for follow-up and targeted measures to improve compliance with follow-up may improve completion of the screening pathway.

Uptake of Bowel Scope (Flexible Sigmoidoscopy) Screening in the English National Programme: the first 14 months.

OBJECTIVE: To examine uptake in the first six pilot centres of the English Bowel Scope Screening (BSS) programme, which began in early 2013 and invites adults aged 55 for a one off Flexible Sigmoidoscopy. METHODS: Between March 2013 and May 2014 the six pilot centres sent 21,187 invitations. Using multivariate logistic regression analysis, we examined variation in uptake by gender, socioeconomic deprivation (using the Index of Multiple Deprivation), area-based ethnic diversity (proportion of non-white residents), screening centre, and appointment time (routine: daytime vs out-of-hours: evening/weekend). RESULTS: Uptake was 43.1%. Men were more likely to attend than women (45% vs 42%; OR 1.136, 95% CI 1.076, 1.199, p < 0.001). Combining data across centres, there was a socioeconomic gradient in uptake, ranging from 33% in the most deprived to 53% in the least deprived quintile. Areas with the highest level of ethnic diversity also had lower uptake (39%) than other areas (41-47%) (all p < 0.02), but there was no gradient. Individuals offered a routine appointment were less likely to attend than those offered an out-of-hours appointment (42% vs. 44%; OR 0.931, 95% CI 0.882, 0.983, p = 0.01). Multivariate analyses confirmed independent effects of deprivation, gender, and centre, but not of ethnic diversity or appointment time. CONCLUSION: Early indications of uptake are encouraging. Future efforts should focus on increasing public awareness of the programme and reducing socioeconomic inequalities.

Evaluation of colonoscopy performance based on post-procedure bleeding complications: application of procedure complexity-adjusted model.

BACKGROUND AND STUDY AIM: High quality colonoscopy requires low complication rates. However in quality assurance, evaluation of individual colonoscopist complication rates is limited because complications are relatively rare events and there is variation in average procedure complexity. The aim of the study was to develop a quality system that adjusted for procedure complexity to monitor bleeding adverse events at both the screening center and colonoscopist levels. METHODS: The study examined the risk factors for post-procedure bleeding from 130 831 colonoscopies conducted between August 2006 and January 2012. Binomial and logistic regression models were used to examine the risk of events against explanatory variables including age, sex, polyps resected, and polyp size. The models were used to produce a procedure-adjusted standardized adverse event ratio (PASAER) based on the ratio of the observed to expected number of adverse events. The primary outcome of interest was to identify centers that were outside a funnel plot outlier level of 99.8 % (3 SDs). RESULTS: Mulivariate models showed that the risk of bleeding was associated with largest resected polyp size, sex, polyp location, and degree of co-morbidity. These variables were used to calculate PASAERs for the 59 screening centers and 286 colonoscopists. The method highlighted one center with a high PASAER of 3.08 (32 observed compared with 10.4 expected events) and one with a low PASAER of 0.34 (10 observed compared with 29.8 expected events), which merited further investigation. CONCLUSIONS: The PASAER provided additional certainty that a crude adverse event rate was not confounded by procedure complexity, thus objectively identifying centers or colonoscopists that required further performance evaluation.

Non-neoplastic findings at colonoscopy after positive faecal occult blood testing: data from the English Bowel Cancer Screening Programme.

BACKGROUND: The aim of the English Bowel Cancer Screening Programme (BCSP) is to diagnose early colorectal cancer and advanced adenomas. However, other findings are also reported at screening colonoscopy. Small studies demonstrate findings other than cancer or adenomas (non-neoplastic findings (NNF)) in 11-25%. OBJECTIVES AND SETTING: Describe the frequency and nature of NNF within the BSCP. METHODS: Data were obtained from the BCSP national database for all individuals undergoing colonoscopic investigation after positive faecal occult blood testing between August 2006 and November 2011. Data included demographics, smoking status, neoplastic findings and NNF. RESULTS: 121728 colonoscopies were analysed. ≥1 NNF were found in 26251 cases (21.6%). Diverticular disease (18875 cases) and haemorrhoids (7011) were the most frequently reported. Inflammatory bowel disease (IBD) was reported in 2152 cases. Individuals with a neoplastic diagnosis were less likely to have an NNF than those without (19.8% v 24.4%, p < 0.001). After adjustment for confounding using multivariable analysis, older age was still associated with a small but statistically significant risk of NNF. CONCLUSIONS: The BCSP generates a significant volume of NNF. A small proportion of individuals were found to have inflammatory bowel disease (IBD) - an important diagnosis with implications for long-term management. BCSP participants should be aware that findings other than neoplasia may be detected and the relevance of these findings to that individual is not known. Reporting of NNF varies between colonoscopists, and potential underreporting is a limitation of this study. Further study is required to establish the impact of NNF on primary and secondary care.

Colonoscopic factors associated with adenoma detection in a national colorectal cancer screening program.

BACKGROUND AND STUDY AIMS: Adenoma detection is a key objective of colonoscopy, particularly in the context of colorectal cancer screening. The aim of this observational study was to identify the technical colonoscopy factors associated with adenoma detection. PATIENTS AND METHODS: The study analyzed data from the English Bowel Cancer Screening Programme. The indication for all colonoscopies was a positive fecal occult blood test. The relationships between the following colonoscopy factors and adenoma detection (one or more adenomas, advanced adenomas, right-sided adenomas, and total number of adenomas) were examined in multivariable analyses: bowel preparation quality, cecal intubation, withdrawal time, rectal retroversion, colonoscopist experience, antispasmodic use, sedation use, and start time of procedure. The following patient factors were controlled for: age, sex, body mass index, smoking, alcohol, deprivation, and geographical location. RESULTS: A total of 31088 colonoscopies were analyzed. The following technical factors increased the relative risk of adenoma detection (P < 0.001 in multivariable analysis unless otherwise stated): cecal intubation, increased withdrawal time, higher quality bowel preparation, intravenous antispasmodic use, earlier procedure start time within a session (P = 0.018), and greater colonoscopist experience. Detection of advanced and right-sided adenomas also increased with these factors. Adenoma detection did not differ between sedated and unsedated colonoscopy (P = 0.143). CONCLUSION: This study demonstrated important associations between colonoscopy practice and adenoma detection. Use of intravenous antispasmodic was associated with increased adenoma detection. The effect of the start time of colonoscopy suggests that endoscopist fatigue may have a deleterious impact on adenoma detection.

Risk factors for adverse events related to polypectomy in the English Bowel Cancer Screening Programme.

BACKGROUND AND STUDY AIMS: The English National Health Service Bowel Cancer Screening Programme (NHSBCSP) is one of the world's largest organized screening programs. Minimizing adverse events is essential for any screening program. Study aims were to determine rates and to examine risk factors for adverse events. PATIENTS AND METHODS: Bleeding and perforations in NHSBCSP colonoscopies between August 2006 and January 2012 were examined. Logistic regression was used to examine risk factors for adverse events, including age, gender, polyp size, morphology, and location. For accurate attribution of adverse events, procedures with resection of only one polyp ("single-polypectomy") were analyzed in detail. RESULTS: 130 831 colonoscopies (167 208 polypectomies) were analyzed, including 30 881 single-polypectomies. Overall bleeding rate was 0.65 %, rate of bleeding requiring transfusion was 0.04 % and perforation rate was 0.06 %. Polypectomy increased bleeding risk 11.14-fold and perforation risk 2.97-fold. Cecal location (but not elsewhere in the proximal colon) and increasing polyp size were the two most important risk factors for bleeding and perforation. After adjustment for polyp size, the odds ratio (OR) relative to the distal colon for bleeding requiring transfusion after cecal snare polypectomy was 13.5 (95 %CI 3.9 - 46.4) and for perforation after cecal nonpedunculated polypectomy it was 12.2 (95 %CI 1.2 - 119.5). CONCLUSION: This is the largest study focusing on polyp-specific risk factors. We have confirmed that the greatest risk factor for both post-polypectomy bleeding and perforation is polyp size. This is the first demonstration of substantial and significantly increased risk for both noteworthy bleeding (requiring transfusion) and perforation from cecal polypectomy for a given polyp size, compared with elsewhere in the colon.