Demographic and comorbidity predictors of adherence to diagnostic colonoscopy in the Danish Colorectal Cancer Screening Program: a nationwide cross-sectional study

Increasing coverage in cervical and colorectal cancer screening by leveraging attendance at breast cancer screening: A cluster-randomised, crossover trial

BACKGROUND

Screening participation remains suboptimal in cervical cancer (CC) and colorectal cancer (CRC) screening despite their effectiveness in reducing cancer-related morbidity and mortality. We investigated the effectiveness of an intervention by leveraging the high participation rate in breast cancer (BC) screening as an opportunity to offer self-sampling kits to nonparticipants in CC and CRC screening.

METHODS AND FINDINGS

A pragmatic, unblinded, cluster-randomised, multiple period, crossover trial was conducted in 5 BC screening units in the Central Denmark Region (CDR) between September 1, 2021 and May 25, 2022. On each of 100 selected weekdays, 1 BC screening unit was randomly allocated as the intervention unit while the remaining units served as controls. Women aged 50 to 69 years attending BC screening at the intervention unit were offered administrative check-up on their CC screening status (ages 50 to 64 years) and CRC screening status (aged 50 to 69), and women with overdue screening were offered self-sampling. Women in the control group received only standard screening offers according to the organised programmes. The primary outcomes were differences between the intervention group and the control group in the total screening coverage for the 2 programmes and in screening participation among women with overdue screening, measured 6 months after the intervention. These were assessed using intention-to-treat analysis, reporting risk differences with 95% confidence intervals (CIs). A total of 27,116 women were included in the trial, with 5,618 (20.7%) in the intervention group and 21,498 (79.3%) in the control group. Six months after the intervention, total coverage was higher in the intervention group as compared with the control group in CC screening (88.3 versus 83.5, difference 4.8 percentage points, 95% CI [3.6, 6.0]; p < 0.001) and in CRC screening (79.8 versus 76.0, difference 3.8 percentage points, 95% CI [2.6, 5.1]; p < 0.001). Among women overdue with CC screening, participation in the intervention group was 32.0% compared with 6.1% in the control group (difference 25.8 percentage points, 95% CI [22.0, 29.6]; p < 0.001). In CRC screening, participation among women overdue with screening in the intervention group was 23.8% compared with 8.9% in the control group (difference 14.9 percentage points, 95% CI [12.3, 17.5]; p < 0.001). Women who did not participate in BC screening were not included in this study.

CONCLUSIONS

Offering self-sampling to women overdue with CC and CRC screening when they attend BC screening was a feasible intervention, resulting in an increase in participation and total coverage. Other interventions are required to reach women who are not participating in BC screening.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05022511. The record of processing activities for research projects in the Central Denmark Region (R. No.: 1-16-02-217-21).

Adherence to follow-up and resource use after abnormal FIT-screening: Evaluation of the Danish colorectal cancer screening program

Background and study aims The effectiveness of colorectal cancer screening programs depends on adherence to surveillance protocols for screening-positive individuals. We evaluated adherence in the Danish population-based screening program and estimated the volume of diagnostic resources required to achieve this adherence. Patients and methods In this register- and population-based study, we included individuals with a positive fecal immunochemical test (FIT) screening from 2014 to 2017 and followed them until mid-2022. All endoscopic, imaging, and surgical procedures performed at public and private hospitals were identified. Adherence to national protocols was reported in terms of proportions and timeliness. Use of diagnostic and surveillance procedures was estimated during a 4-year post-screening period. Results Among 82,221 individuals with a positive FIT test, 84% had a baseline colonoscopy within 1 month. After removal of intermediate or high-risk adenomas, 12% and 6%, respectively, did not have any follow-up. Only ~50% had timely surveillance. Approximately 10% to 20%, depending on their referral diagnosis, did not have a second surveillance colonoscopy. In addition, 12% with a negative colonoscopy had a second colonoscopy within 4 years. Conclusions High adherence to baseline colonoscopy after positive FIT-screening is followed by lower adherence throughout the adenoma surveillance program. Better adherence to the guidelines could potentially improve the effectiveness and efficiency of the screening program.

The prevalence of comorbidity in the lung cancer screening population: A systematic review and meta-analysis

OBJECTIVE

Comorbidity is associated with adverse outcomes for all lung cancer patients, but its burden is less understood in the context of screening. This review synthesises the prevalence of comorbidities among lung cancer screening (LCS) candidates and summarises the clinical recommendations for screening comorbid individuals.

METHODS

We searched MEDLINE, EMBASE, EBM Reviews, and CINAHL databases from January 1990 to February 2021. We included LCS studies that reported a prevalence of comorbidity, as a prevalence of a particular condition, or as a summary score. We also summarised LCS clinical guidelines that addressed comorbidity or frailty for LCS as a secondary objective for this review. Meta-analysis was used with inverse-variance weights obtained from a random-effects model to estimate the prevalence of selected comorbidities.

RESULTS

We included 69 studies in the review; seven reported comorbidity summary scores, two reported performance status, 48 reported individual comorbidities, and 12 were clinical guideline papers. The meta-analysis of individual comorbidities resulted in an estimated prevalence of 35.2% for hypertension, 23.5% for history of chronic obstructive pulmonary disease (COPD) (10.7% for severe COPD), 16.6% for ischaemic heart disease (IHD), 13.1% for peripheral vascular disease (PVD), 12.9% for asthma, 12.5% for diabetes, 4.5% for bronchiectasis, 2.2% for stroke, and 0.5% for pulmonary fibrosis.

CONCLUSIONS

Comorbidities were highly prevalent in LCS populations and likely to be more prevalent than in other cancer screening programmes. Further research on the burden of comorbid disease and its impact on screening uptake and outcomes is needed. Identifying individuals with frailty and comorbidities who might not benefit from screening should become a priority in LCS research.

Subsequent participation in organized FIT based screening following screen-derived colonoscopy - A Danish nationwide cohort study

Introduction

In the Danish National Colorectal Cancer (CRC) screening program, participants with screen-detected low-risk adenomas are invited to a new faecal immunochemical test (FIT) screening after two years. However, participation rate in next FIT screening is unknown. We aimed to investigate this subsequent participation rate within the Danish CRC screening program.

Methods

This nationwide register-based study included participants aged 50-72 years registered with FIT screening in the Danish CRC screening program between January 1, 2016, and June 30, 2017. Participants were included if their index FIT was negative or if it was positive and the subsequent colonoscopy detected low-risk adenomas. Invitees were categorized as subsequent participants if they returned a FIT within 135 days following the invitation to screening. We estimated the relative risk for participation depending on screening outcome, age, and sex.

Result

415,107 with a negative result and 5,550 with low-risk adenomas were included. 86.0% (85.9;86.1) of the invitees with a negative result participated in the subsequent screening, while 71.8% (70.6;73.0) of the invitees with low-risk adenomas participated subsequently. The risk of participation in the subsequent screening was significantly lower among all age groups of men and women with low-risk adenomas compared to similar groups with negative results.

Conclusion

Invitees with low-risk adenomas detected at their initial colonoscopy are less likely to participate in the subsequent screening than invitees with negative results. This association was found in all age groups and for both sexes. Further studies are necessary to assess whether non-attendance is more pronounced in specific subgroups.

Effect of comorbidity assessed by the Charlson Comorbidity Index on the length of stay, costs, and mortality among colorectal cancer patients undergoing colorectal surgery

OBJECTIVE

Charlson Comorbidity Index (CCI) is a good predictor for hospitalization cost and mortality among patients with chronic disease. However, the impact of CCI on patients after colorectal cancer surgery is unclear. This study aims to investigate the influence of comorbidity assessed by CCI on length of stay, hospitalization costs, and in-hospital mortality in patients with colorectal cancer (CRC) who underwent surgical resection.

METHODS

This historical cohort study collected 10,271 adult inpatients for CRC undergoing resection surgery in 33 tertiary hospitals between January 2018 and December 2019. All patients were categorized by the CCI score into four classes: 0, 1,2, and ≥3. Linear regression was used for outcome indicators as continuous variables and logical regression for categorical variables. EmpowerStats software and R were used for data analysis.

RESULTS

Of all 10,271 CRC patients, 51.72% had at least one comorbidity. Prevalence of metastatic solid tumor (19.68%, except colorectal cancer) and diabetes without complication (15.01%) were the major comorbidities. The highest average cost of hospitalization (86,761.88 CNY), length of stay (18.13 days), and in-hospital mortality (0.89%) were observed in patients with CCI score ≥3 compared to lower CCI scores (p < .001). Multivariate regression analysis showed that the CCI score was associated with hospitalization costs (β, 7340.46 [95% confidence interval (CI) (5710.06-8970.86)], p < .001), length of stay (β, 1.91[95%CI (1.52-2.30)], p < .001), and in-hospital mortality(odds ratio (OR),16.83[95%CI (2.23-126.88)], p = .0062) after adjusted basic clinical characteristics, especially when CCI score ≥3. Notably, the most specific complication associated with hospitalization costs and length of stay was metastatic solid tumor, while the most notable mortality-specific comorbidity was moderate or severe renal disease.

CONCLUSION

The research work has discovered a strong link between CCI and clinical plus economic outcomes in patients with CRC who underwent surgical resection.

Appropriateness of fecal immunochemical testing utilization for colorectal cancer screening at an academic center

Fecal immunochemical testing (FIT) has become the most utilized test for colorectal cancer (CRC) screening. This retrospective quality assurance report analyzed data for 411 patients from one academic center in Central New York who underwent FIT between September 2015 and September 2016. All 67 positive tests and 344 of 952 negative tests were analyzed. Subjects from the FIT-negative "control group" were chosen at random. The mean age was 67 years and the male/female distribution was 391/20, with differences between the FIT-positive and -negative groups. FIT was inappropriately used in 210 (51%) of the 411 patients. The most common reasons for inappropriate FIT use were a documented refusal of colonoscopy (39.60% of inappropriate use), FIT occurring within the recommended surveillance interval from previous colonoscopy (27.98%), and a Charlson Co-Morbidity Index score ≥5 (22.87%). Other reasons were a history of adenoma (9.25%), family history of CRC/high-risk adenoma <60 years of age (5.84%), active/overt gastrointestinal bleed (4.87%), history of CRC (1.46%), and history of inflammatory bowel disease (1.46%). The results of this study show that FIT is being utilized inappropriately about 50% of the time.

Effect of Chronic Comorbidities on Follow-up Colonoscopy After Positive Colorectal Cancer Screening Results: A Population-Based Cohort Study

INTRODUCTION

Fecal occult blood tests (FOBTs) are colorectal cancer screening tests used to identify individuals requiring further investigation with colonoscopy. Delayed colonoscopy after positive FOBT (FOBT+) is associated with poorer cancer outcomes. We assessed the effect of comorbidity on colonoscopy receipt within 12 months after FOBT+.

METHODS

Population-based healthcare databases from Ontario, Canada, were linked to assemble a cohort of 50-74-year-old individuals with FOBT+ results between 2008 and 2017. The associations between comorbidities and colonoscopy receipt within 12 months after FOBT+ were examined using multivariable cause-specific hazard regression models.

RESULTS

Of 168,701 individuals with FOBT+, 80.5% received colonoscopy within 12 months. In multivariable models, renal failure (hazard ratio [HR] 0.71, 95% confidence interval [CI] 0.62-0.82), heart failure (HR 0.77, CI 0.75-0.80), and serious mental illness (HR 0.88, CI 0.85-0.92) were associated with the lowest colonoscopy rates, compared with not having each condition. The number of medical conditions was inversely associated with colonoscopy uptake (≥4 vs 0: HR 0.64, CI 0.58-0.69; 3 vs 0: HR 0.75, CI 0.72-0.78; and 2 vs 0: HR 0.87, CI 0.85-0.89). Having both medical and mental health conditions was associated with a lower colonoscopy uptake relative to no comorbidity (HR 0.88, CI 0.87-0.90).

DISCUSSION

Persons with medical and mental health conditions had lower colonoscopy rates after FOBT+ than those without these conditions. Better strategies are needed to optimize colorectal cancer screening and follow-up in individuals with comorbidities.

Early detection of colorectal neoplasia: application of a blood-based serological protein test on subjects undergoing population-based screening

BACKGROUND

Blood-based biomarkers used for colorectal cancer screening need to be developed and validated in appropriate screening populations. We aimed to develop a cancer-associated protein biomarker test for the detection of colorectal cancer in a screening population.

METHODS

Participants from the Danish Colorectal Cancer Screening Program were recruited. Blood samples were collected prior to colonoscopy. The cohort was divided into training and validation sets. We present the results of model development using the training set. Age, sex, and the serological proteins CEA, hsCRP, TIMP-1, Pepsinogen-2, HE4, CyFra21-1, Galectin-3, ferritin and B2M were used to develop a signature test to discriminate between participants with colorectal cancer versus all other findings at colonoscopy.

RESULTS

The training set included 4048 FIT-positive participants of whom 242 had a colorectal cancer. The final model for discriminating colorectal cancer versus all other findings at colonoscopy had an AUC of 0.70 (95% CI: 0.66-0.74) and included age, sex, CEA, hsCRP, HE4 and ferritin.

CONCLUSION

The performance of the biomarker signature in this FIT-positive screening population did not reflect the positive performance of biomarker signatures seen in symptomatic populations. Additional biomarkers are needed if the serological biomarkers are to be used as a frontline screening test.

Risk-stratified selection to colonoscopy in FIT colorectal cancer screening: development and temporal validation of a prediction model

BACKGROUND

Faecal immunochemical tests (FITs) yield many false positives and challenge colonoscopy capacity in colorectal cancer (CRC) screening programmes. We aimed to develop a risk-based selection of participants to undergo diagnostic colonoscopy.

METHODS

The study was observational and used registry data from the Danish CRC screening programme. We included all participants invited 2014-2016 with a positive FIT (≥ 20 μg fHb/g) who underwent colonoscopy (n = 56,459). We predicted the risk of CRC or advanced neoplasia (AN) from age, gender and FIT value using logistic regression. We evaluated calibration and discrimination and conducted temporal validation. We compared the number of CRCs and adenomas identified by risk cut-offs and by a corresponding FIT cut-off.

RESULTS

AUCs were 74.9% (95% CI: 73.6; 76.3) and 67.4% (95% CI: 66.8%; 68.0%) for the models predicting CRC and AN in the validation dataset. The cut-off of CRC risk calculated from age, gender and FIT value identified 1.03 times (95% CI: 1.02; 1.05) more CRCs and 1.01 times (95% CI: 1.01; 1.01) more medium/high-risk adenomas compared with the corresponding FIT cut-off.

CONCLUSIONS

With existing data, risk-stratified FIT screening using a risk cut-off instead of a FIT cut-off can slightly improve the selection to colonoscopy of those at highest risk of cancer and adenomas.

Characteristics of non-participants in a randomized colorectal cancer screening trial comparing sigmoidoscopy and faecal immunochemical testing

Public health systems should guarantee universal access to health care services, including cancer screening. We assessed whether certain population subgroups were underrepresented among participants in colorectal cancer screening with sigmoidoscopy and faecal immunochemical testing (FIT). Between 2012 and 2019, about 140 000 individuals aged 50 to 74 years were randomly invited to once‐only sigmoidoscopy or first round of FIT screening. Our study included 46 919 individuals invited to sigmoidoscopy and 70 019 to FIT between 2012 and 2017. We used logistic regression models to evaluate if demographic and socioeconomic factors and use of certain drugs were associated with participation. Twenty‐four thousand one hundred and fifty‐nine (51.5%) individuals attended sigmoidoscopy and 40 931 (58.5%) FIT screening. Male gender, young age, low education and income, being retired or unemployed, living alone, being an immigrant, long driving time to screening centre, and use of antidiabetic and psychotropic drugs were associated with low participation in both screening groups. Many of these factors also predicted low acceptance of colonoscopy after positive FIT. While male gender, young age and living alone were more strongly associated with nonparticipation in FIT than sigmoidoscopy, low education and income, being retired or immigrant and long driving time were more strongly associated with nonparticipation in sigmoidoscopy than FIT. In conclusion, participation was lower in sigmoidoscopy than FIT. Predictors of nonparticipation were similar between arms. However, low socioeconomic status, being an immigrant and long driving time affected participation more in sigmoidoscopy screening, suggesting that FIT may guarantee more equal access to screening services than sigmoidoscopy.

Yield and Risk Factors for Advanced Colorectal Neoplasia and Long-term Outcomes in Veterans With 3 or More Nonadvanced Adenomas

BACKGROUND AND AIMS

Until recently, guidelines recommended a 3-year surveillance colonoscopy for persons with 3 to 10 nonadvanced adenomas (NAA). In this study, we quantify yield for metachronous advanced neoplasia (AN); attempt to identify risk factors for AN; and measure colorectal cancer (CRC) incidence and mortality.

METHODS

We used natural language processing to screen an existing data set for Veterans with 3 to 10 NAA. We manually reviewed colonoscopy and pathology reports to verify baseline findings and determine results of subsequent colonoscopy (sCY). Baseline features were extracted from the electronic medical record (EMR) and a national data set, CRC incidence was obtained from the Veterans Affairs cancer registry, and CRC mortality from the National Death Index through September 30, 2017. CRC incidence and mortality were compared between Veterans who did versus did not have sCY.

RESULTS

Natural language processing identified 3673 Veterans who potentially had 3 to 10 NAA, of which 1672 were excluded after EMR review. In the analytical cohort of 2001 subjects, 1178 (59%) had sCY at a mean (SD) follow-up of 4.3 (2.2) years. The sCY group was younger (mean age: 61 vs. 67 y; P<0.01) and were less likely to have diabetes (27% vs. 31%; P=0.02) and congestive heart failure (4% vs. 9%; P<0.01). sCY showed AN in 182 subjects (15.5%). Baseline features were no different between those with versus without metachronous AN. Subjects with sCY had a greater CRC incidence (n=7 vs. n=0; P=0.046), but there was no difference in CRC mortality (0 for both subgroups).

CONCLUSIONS

Among patients with 3 to 10 NAA on index colonoscopy who underwent sCY, AN was present in 15.5% at mean follow-up of 4.3 years. No risk factors for AN were identified. CRC incidence, but not CRC mortality, was higher among those with sCY.

Associations between comorbidities and advanced stage diagnosis of lung, breast, colorectal, and prostate cancer: A systematic review and meta-analysis

Comorbidities and advanced stage diagnosis (ASD) are both associated with poorer cancer outcomes, but the association between comorbidities and ASD is poorly understood. We summarized epidemiological evidence on the association between comorbidities and ASD of selected cancers in a systematic review and meta-analysis. We searched PubMed and Web of Science databases up to June 3rd, 2021 for studies assessing the association between comorbidities and ASD of lung, breast, colorectal, or prostate cancer. Summary odds ratios (ORs) and 95% confidence intervals (95%CIs) were calculated using random-effects models. Also, potential variations in the associations between comorbidities and ASD by cancer type were investigated using random-effects meta-regression. Thirty-seven studies were included in this review, including 8,069,397 lung, breast, colorectal, and prostate cancer patients overall. The Charlson comorbidity index score was positively associated with ASD (stages III-IV) of breast cancer but was inversely associated with ASD of lung cancer (p_interaction = 0.004). Regarding specific comorbidities, diabetes was positively associated with ASD (OR = 1.17, 95%CI = 1.09-1.26), whereas myocardial infarction was inversely associated with ASD (OR = 0.84, 95%CI = 0.75-0.95). The association between renal disease and ASD differed by cancer type (p_interaction < 0.001). A positive association was found with prostate cancer (OR = 2.02, 95%CI = 1.58-2.59) and an inverse association with colorectal cancer (OR = 0.84, 95%CI = 0.70-1.00). In summary, certain comorbidities (e.g., diabetes) may be positively associated with ASD of several cancer types. It needs to be clarified whether closer monitoring for early cancer signs or screening in these patients is reasonable, considering the problem of over-diagnosis particularly relevant in patients with short remaining life expectancy such as those with comorbidities. Also, evaluation of the cost-benefit relationship of cancer screening according to the type and severity of comorbidity (rather than summary scores) may be beneficial for personalized cancer screening in populations with chronic diseases.

Disparities in Colorectal Cancer Screening Practices in a Midwest Urban Safety-Net Healthcare System

AIMS

Although colorectal cancer screening (CRC) using stool-based test is well-studied, evidence on fecal immunochemical test (FIT) patterns in a safety-net healthcare system utilizing opportunistic screening is limited. We studied the FIT completion rates and adenoma detection rate (ADR) of positive FIT-colonoscopy (FIT-C) in an urban safety-net system.

METHODS

We performed a retrospective cross-sectional chart review on individuals ≥ 50 years who underwent CRC screening using FIT or screening colonoscopy, 09/01/2017-08/30/2018. Demographic differences in FIT completion were studied; ADR of FIT-C was compared to that of screening colonoscopy.

RESULTS

Among 13,427 individuals with FIT ordered, 7248 (54%) completed the stool test and 230 (48%) followed up a positive FIT with colonoscopy. Increasing age (OR 1.01, CI 1.01-1.02), non-Hispanic Blacks (OR 0.87, CI 0.80-0.95, p = 0.002), current smokers (OR 0.84, CI 0.77-0.92, p < 0.0001), those with Medicaid (OR 0.86, CI 0.77-0.96, p = 0.006), commercial insurance (OR 0.85, CI 0.78-0.94, p = 0.002), CCI score ≥ 3 (OR 0.82, CI 0.74-0.91, p < 0.0001), orders by family medicine providers (OR 0.87, CI 0.81-0.94, p < 0.0001) were associated with lower completion of stool test. Individuals from low median household income cities had lower follow-up of positive FIT, OR 0.43, CI 0.21-0.86, p = 0.017. ADR of FIT-C was higher than that of screening colonoscopy.

CONCLUSION

Adherence to CRC screening is low in safety-net systems employing opportunistic screening. Understanding demographic differences may allow providers to formulate targeted strategies in high-risk vulnerable groups.

Differential effects of colorectal cancer screening across sociodemographic groups in Denmark: a register-based study

INTRODUCTION

Colorectal cancer (CRC) does not affect different sociodemographic groups uniformly. CRC screening programmes could seek to reduce this inequality; however, the screening programmes themselves might be subject to differential participation across sociodemographic groups. This study investigates the sociodemographic inequality at all steps in Denmark's nationwide CRC screening programme: screening participation, faecal immunochemical test (FIT) results, colonoscopy compliance, CRC diagnosis, and cancer stage.

MATERIAL AND METHODS

This cohort study includes all first-time invitees from the beginning of the Danish population-based CRC screening programme from 1 March 2014 to 31 December 2017.

RESULTS

Sixty-four percent of the invitees participated in the screening programme, and of those 7% were FIT-positive. After being invited to further diagnostic procedures, 90% responded to the invitation, and among those 5% were CRC-positive. Among those diagnosed with CRC, 9% were stage IV. Through multivariable analyses, we identified sociodemographic inequalities in all steps of the screening programme from returning a stool sample to being diagnosed with CRC. Specifically, we identified inequalities across sex, age, migration status, relationship status, the screening status of one's partner, education, income, and use of health services. Women were more likely to participate compared to men (RR = 1.13; 95% CI: 1.12-1.13), but had a lower risk of a positive FIT result (RR = 0.67; 95% CI: 0.66-0.68) and of a CRC diagnosis (RR = 0.88; 95% CI: 0.82-0.93) compared to men. The likelihood of participating as well as the risk of positive FIT results and CRC diagnosis increased with age.

CONCLUSION

All steps of the screening programme were subject to sociodemographic inequalities. Interventions are needed to target groups identified as having lower uptake as well as high-risk of being FIT- and/or CRC-positive. These groups include males, individuals aged 60+ years and individuals who do not visit their GP regularly.

Barriers to completing colonoscopy after a positive fecal occult blood test

Background

Colorectal cancer leads to significant morbidity and mortality. Early detection and treatment are essential. Screening using fecal occult blood tests has increased significantly, but adherence to colonoscopy follow-up is suboptimal, increasing CRC mortality risk.

The aim of this study was to identify barriers to colonoscopy following a positive FOBT at the level of the patient, physician, organization and policymakers.

Methods

This mixed methods study was conducted at two health care organizations in Israel. The study included retrospective analyses of 45,281 50–74 year-old members with positive fecal immunochemical tests from 2010 to 2014, and a survey of 772 patients with a positive test during 2015, with and without follow-up. The qualitative part of the study included focus groups with primary physicians and gastroenterologists and in-depth interviews with opinion leaders in healthcare.

Results

Patient lack of comprehension regarding the test was the strongest predictor of non-adherence to follow-up. Older age, Arab ethnicity, and lower socio economic status significantly reduced adherence. We found no correlation with gender, marital status, patient activation, waiting time for appointments or distance from gastroenterology clinics. Primary care physicians underestimate non-adherence rates. They feel responsible for patient follow-up, but express lack of time and skills that will allow them to ensure adherence among their patients. Gastroenterologists do not consider fecal occult blood an effective tool for CRC detection, and believe that all patients should undergo colonoscopy. Opinion leaders in the healthcare field do not prioritize the issue of follow-up after a positive screening test for colorectal cancer, although they understand the importance.

Conclusions

We identified important barriers that need to be addressed to improve the effectiveness of the screening program. Targeted interventions for populations at risk for non-adherence, specifically for those with low literacy levels, and better explanation of the need for follow-up as a routine need to be set in place. Lack of agreement between screening recommendations and gastroenterologist opinion, and lack of awareness among healthcare authority figures negatively impact the screening program need to be addressed at the organizational and national level.

Trial registration

This study was approved by the IRB in both participating organizations (Meuhedet Health Care Institutional Review Board #02–2–5-15, Maccabi Healthcare Institutional Review Board BBI-0025-16). Participant consent was waived by both IRB’s.

Potential for prevention: a cohort study of colonoscopies and removal of adenomas in a FIT-based colorectal cancer screening programme

Introduction: Evidence suggests that colorectal cancer (CRC) screening using guaiac faecal occult blood tests (gFOBT) reduces the CRC burden by facilitating timely removal of adenomas. Yet, the faecal immunochemical test (FIT) is being implemented in many countries. The aim of this study was to analyse the risk of having adenomas detected when invited for FIT-based screening as compared to those not yet invited. Material and Methods: The study was designed as a register-based retrospective cohort study. The potential for prevention was estimated as number of individuals who had no adenomas, non-advanced adenomas, and advanced adenomas detected per 1000 invited/not yet invited individuals and the relative risk (RR) of each of the three outcomes. Results: A total of 1,359,340 individuals were included, 29.6% of whom had been invited and 70.4% had not yet been invited to participate in CRC screening. Compared with the not yet invited population, the invited group had a RR of no adenomas of 2.28 (2.22-2.34) and a RR of advanced adenomas of 7.41 (6.93-7.91). The RR of colonoscopy was 2.93 (2.87-2.99) for the invited population compared with the not yet invited population. Conclusion: The RR of having a colonoscopy was three times higher among those invited compared to those not yet invited for CRC screening and twice as often those who had been invited compared to those not yet invited had no adenomas detected. Still, the risk of advanced adenomas was more than seven times higher among the invited population, indicating that the screening programme holds great potential for reducing the CRC burden. Abbreviations: CI: Confidence interval; CRC: Colorectal cancer; FIT: Faecal immunochemical test; ICD: International Classification of Disease; RR: Relative risk.