Screening for colorectal cancer: the cost to find an advanced adenoma

Utility-Based Multicriteria Model for Screening Patients under the COVID-19 Pandemic

In this paper, a utility-based multicriteria model is proposed to support the physicians to deal with an important medical decision—the screening decision problem—given the squeeze put on resources due to the COVID-19 pandemic. Since the COVID-19 emerged, the number of patients with an acute respiratory failure has increased in the health units. This chaotic situation has led to a deficiency in health resources. Thus, this study, using the concepts of the multiattribute utility theory (MAUT), puts forward a mathematical model to aid physicians in the screening decision problem. The model is used to generate which of the three alternatives is the best one for where patients with suspected COVID-19 should be treated, namely, an intensive care unit (ICU), a hospital ward, or at home in isolation. Also, a decision information system, called SIDTriagem, is constructed and illustrated to operate the mathematical model proposed.

Cost-Effectiveness of Colorectal Cancer Screening Strategies-A Systematic Review

BACKGROUND & AIMS

Widespread screening for colorectal cancer (CRC) has reduced its incidence and mortality. Previous studies investigated the economic effects of CRC screening. We performed a systematic review to provide up-to-date evidence of the cost effectiveness of CRC screening strategies by answering 3 research questions.

METHODS

We searched PubMed, National Institute for Health Research Economic Evaluation Database, Social Sciences Citation Index (via the Web of Science), EconLit (American Economic Association) and 3 supplemental databases for original articles published in English from January 2010 through December 2017. All monetary values were converted to US dollars (year 2016). For all research questions, we extracted, or calculated (if necessary), per-person costs and life years (LYs) and/or quality-adjusted LYs, as well as the incremental costs per LY gained or quality-adjusted LY gained compared with the baseline strategy. A cost-saving strategy was defined as one that was less costly and equally or more effective than the baseline strategy. The net monetary benefit approach was used to answer research question 2.

RESULTS

Our review comprised 33 studies (17 from Europe, 11 from North America, 4 from Asia, and 1 from Australia). Annual and biennial guaiac-based fecal occult blood tests, annual and biennial fecal immunochemical tests, colonoscopy every 10 years, and flexible sigmoidoscopy every 5 years were cost effective (even cost saving in most US models) compared to no screening. In addition, colonoscopy every 10 years was less costly and/or more effective than other common strategies in the United States. Newer strategies such as computed tomographic colonography, every 5 or 10 years, was cost effective compared with no screening.

CONCLUSIONS

In an updated review, we found that common CRC screening strategies and computed tomographic colonography continued to be cost effective compared to no screening. There were discrepancies among studies from different regions, which could be associated with the model types or model assumptions.

Reduction of faecal immunochemical test false-positive results using a signature based on faecal bacterial markers

BACKGROUND

Colorectal cancer is the second commonest cause of cancer mortality. Some countries are implementing colorectal cancer screening to detect lesions at an early stage using non-invasive tools like the faecal immunochemical test. Despite affordability, this test shows a low sensitivity for precancerous lesions and a low positive predictive value for colorectal cancer, resulting in a high false-positive rate.

AIM

To develop a new, non-invasive colorectal cancer screening tool based on bacterial faecal biomarkers, which in combination with the faecal immunochemical test, could allow a reduction in the false-positive rate. This tool is called risk assessment of intestinal disease for colorectal cancer (RAID-CRC).

METHODS

We performed both the faecal immunochemical test and the bacterial markers analysis (RAID-CRC test) in stool samples from individuals with normal colonoscopy (167), non-advanced adenomas (88), advanced adenomas (30) and colorectal cancer (48). All the participants showed colorectal cancer-associated symptoms.

RESULTS

Performance of the faecal immunochemical test for advanced neoplasia (ie advanced adenoma and colorectal cancer) was determined by using the cut-off value established in Catalonia (20 µg haemoglobin/g of faeces) for a population-based screening approach. Sensitivity and specificity values of 83% and 80%, respectively, and positive and negative predictive values of 56% and 94%, respectively, were obtained. When both the immunological and the biological analysis were combined, the corresponding values were 80% and 90% for sensitivity and specificity, respectively, and 70% and 94% for positive and negative predictive values, respectively, resulting in a 50% reduction of the false-positive rate.

CONCLUSIONS

RAID-CRC test allows a substantial reduction in the faecal immunochemical test false-positive results (50%) in a symptomatic population. Further validation is indicated in a colorectal cancer-screening scenario.

Real-time prediction of inpatient length of stay for discharge prioritization

OBJECTIVE

Hospitals are challenged to provide timely patient care while maintaining high resource utilization. This has prompted hospital initiatives to increase patient flow and minimize nonvalue added care time. Real-time demand capacity management (RTDC) is one such initiative whereby clinicians convene each morning to predict patients able to leave the same day and prioritize their remaining tasks for early discharge. Our objective is to automate and improve these discharge predictions by applying supervised machine learning methods to readily available health information.

MATERIALS AND METHODS

The authors use supervised machine learning methods to predict patients' likelihood of discharge by 2 p.m. and by midnight each day for an inpatient medical unit. Using data collected over 8000 patient stays and 20 000 patient days, the predictive performance of the model is compared to clinicians using sensitivity, specificity, Youden's Index (i.e., sensitivity + specificity - 1), and aggregate accuracy measures.

RESULTS

The model compared to clinician predictions demonstrated significantly higher sensitivity (P < .01), lower specificity (P < .01), and a comparable Youden Index (P > .10). Early discharges were less predictable than midnight discharges. The model was more accurate than clinicians in predicting the total number of daily discharges and capable of ranking patients closest to future discharge.

CONCLUSIONS

There is potential to use readily available health information to predict daily patient discharges with accuracies comparable to clinician predictions. This approach may be used to automate and support daily RTDC predictions aimed at improving patient flow.

Colorectal Cancer Screening Based on Age and Gender: A Cost-Effectiveness Analysis

We evaluated whether age- and gender-based colorectal cancer screening is cost-effective.Recent studies in the United States identified age and gender as 2 important variables predicting advanced proximal neoplasia, and that women aged <60 to 70 years were more suited for sigmoidoscopy screening due to their low risk of proximal neoplasia. Yet, quantitative assessment of the incremental benefits, risks, and cost remains to be performed.Primary care screening practice (2008-2015).A Markov modeling was constructed using data from a screening cohort. The following strategies were compared according to the Incremental Cost Effectiveness Ratio (ICER) for 1 life-year saved: flexible sigmoidoscopy (FS) 5 yearly; colonoscopy 10 yearly; FS for each woman at 50- and 55-year old followed by colonoscopy at 60- and 70-year old; FS for each woman at 50-, 55-, 60-, and 65-year old followed by colonoscopy at 70-year old; FS for each woman at 50-, 55-, 60-, 65-, and 70-year old. All male subjects received colonoscopy at 50-, 60-, and 70-year old under strategies 3 to 5.From a hypothetical population of 100,000 asymptomatic subjects, strategy 2 could save the largest number of life-years (4226 vs 2268 to 3841 by other strategies). When compared with no screening, strategy 5 had the lowest ICER (US$42,515), followed by strategy 3 (US$43,517), strategy 2 (US$43,739), strategy 4 (US$47,710), and strategy 1 (US$56,510). Strategy 2 leads to the highest number of bleeding and perforations, and required a prohibitive number of colonoscopy procedures. Strategy 5 remains the most cost-effective when assessed with a wide range of deterministic sensitivity analyses around the base case.From the cost effectiveness analysis, FS for women and colonoscopy for men represent an economically favorable screening strategy. These findings could inform physicians and policy-makers in triaging eligible subjects for risk-based screening, especially in countries with limited colonoscopic resources. Future research should study the acceptability, feasibility, and feasibility of this risk-based strategy in different populations.

The comparative cost-effectiveness of colorectal cancer screening using faecal immunochemical test vs. colonoscopy

Faecal immunochemical tests (FITs) and colonoscopy are two common screening tools for colorectal cancer(CRC). Most cost-effectiveness studies focused on survival as the outcome, and were based on modeling techniques instead of real world observational data. This study evaluated the cost-effectiveness of these two tests to detect colorectal neoplastic lesions based on data from a 5-year community screening service. The incremental cost-effectiveness ratio (ICER) was assessed based on the detection rates of neoplastic lesions, and costs including screening compliance, polypectomy, colonoscopy complications, and staging of CRC detected. A total of 5,863 patients received yearly FIT and 4,869 received colonoscopy. Compared with FIT, colonoscopy detected notably more adenomas (23.6% vs. 1.6%) and advanced lesions or cancer (4.2% vs. 1.2%). Using FIT as control, the ICER of screening colonoscopy in detecting adenoma, advanced adenoma, CRC and a composite endpoint of either advanced adenoma or stage I CRC was US$3,489, US$27,962, US$922,762 and US$23,981 respectively. The respective ICER was US$3,597, US$439,513, -US$2,765,876 and US$32,297 among lower-risk subjects; whilst the corresponding figure was US$3,153, US$14,852, US$184,162 and US$13,919 among higher-risk subjects. When compared to FIT, colonoscopy is considered cost-effective for screening adenoma, advanced neoplasia, and a composite endpoint of advanced neoplasia or stage I CRC.

Screening strategies for colorectal cancer among patients with nonalcoholic fatty liver disease and family history

Patients with nonalcoholic fatty liver disease (NAFLD) and family history of colorectal cancer (CRC) are at higher risks but how they should be screened remains uncertain. Hence, we evaluated the cost-effectiveness of CRC screening among patients with NAFLD and family history by different strategies. A hypothetical population of 100,000 subjects aged 40-75 years receive: (i) yearly fecal immunochemical test (FIT) at 50 years; (ii) flexible sigmoidoscopy (FS) every 5 years at 50 years; (iii) colonoscopy 10 yearly at 50 years; (iv) colonoscopy 10 yearly at 50 years among those with family history/NAFLD and yearly FIT at 50 years among those without; (v) colonoscopy 10 yearly at 40 years among those with family history/NAFLD and yearly FIT at 50 years among those without and (vi) colonoscopy 10 yearly at 40 years among those with family history/NAFLD and colonoscopy 10 yearly at 50 years among those without. The incremental cost-effectiveness ratio (ICER) was studied by Markov modeling. It was found that colonoscopy, FS and FIT reduced incidence of CRC by 49.5, 26.3 and 23.6%, respectively. Using strategies 4, 5 and 6, the corresponding reduction in CRC incidence was 29.9, 30.9 and 69.3% for family history, and 33.2, 34.7 and 69.8% for NAFLD. Compared with no screening, strategies 4 (US$1,018/life-year saved) and 5 (US$7,485) for family history offered the lowest ICER, whilst strategy 4 (US$5,877) for NAFLD was the most cost-effective. These findings were robust when assessed with a wide range of deterministic sensitivity analyses around the base case. These indicated that screening patients with family history or NAFLD by colonoscopy at 50 years was economically favorable.

The cost-effectiveness of screening for colorectal cancer

BACKGROUND

Published decision analyses show that screening for colorectal cancer is cost-effective. However, because of the number of tests available, the optimal screening strategy in Canada is unknown. We estimated the incremental cost-effectiveness of 10 strategies for colorectal cancer screening, as well as no screening, incorporating quality of life, noncompliance and data on the costs and benefits of chemotherapy.

METHODS

We used a probabilistic Markov model to estimate the costs and quality-adjusted life expectancy of 50-year-old average-risk Canadians without screening and with screening by each test. We populated the model with data from the published literature. We calculated costs from the perspective of a third-party payer, with inflation to 2007 Canadian dollars.

RESULTS

Of the 10 strategies considered, we focused on three tests currently being used for population screening in some Canadian provinces: low-sensitivity guaiac fecal occult blood test, performed annually; fecal immunochemical test, performed annually; and colonoscopy, performed every 10 years. These strategies reduced the incidence of colorectal cancer by 44%, 65% and 81%, and mortality by 55%, 74% and 83%, respectively, compared with no screening. These strategies generated incremental cost-effectiveness ratios of $9159, $611 and $6133 per quality-adjusted life year, respectively. The findings were robust to probabilistic sensitivity analysis. Colonoscopy every 10 years yielded the greatest net health benefit.

INTERPRETATION

Screening for colorectal cancer is cost-effective over conventional levels of willingness to pay. Annual high-sensitivity fecal occult blood testing, such as a fecal immunochemical test, or colonoscopy every 10 years offer the best value for the money in Canada.

Pecuniary compensation increases participation in screening for colorectal cancer

The participation rate in medical screening programmes is typically below 100%, which means that not all potential health benefits are fully exploited. In this paper, the prospect of pecuniary compensation is tested as a method of increasing the participation rate. We propose a model explaining the individual's probability of participating in screening for colorectal cancer when he is offered pecuniary compensation, given that he did not participate when first invited. The participant's decision is based on both known and uncertain factors. The estimation is conducted in two steps, where a binary probit model is used in each. We find that pecuniary compensation increases the probability of participation, and that an individual's participation probability systematically varies with variables such as travel expenses, income, age, education level, expected benefit from the screening, use of health-care services, genetic predisposition and subjective health status. Using the results from the estimation, we predict changes in the participation rate for different levels of compensation and estimate the cost per additional individual screened. The cost per additional individual screened is 808, including 25 in compensation; this cost increases with the level of compensation.

The costs of colonoscopy in a Canadian hospital using a microcosting approach

BACKGROUND

Colonoscopy has become accepted as one of the most effective methods of screening patients for colorectal cancer, and is used to remove the majority of colonic adenomas.

OBJECTIVE

Because of the paucity of such estimates in the literature and the significant number of candidates for this procedure, the present study was performed to estimate the direct hospital costs of both diagnostic and therapeutic (polypectomy) colonoscopy.

METHODS

A microcosting methodology was used to itemize the costs of colonoscopy. Variable and fixed costs were divided into labour, supplies, equipment and overhead costs. A third-party payer perspective was adopted. All costs are expressed in 2007 Canadian dollars.

RESULTS

The cost of a diagnostic colonoscopy was $157 and the cost of a therapeutic colonoscopy was $199. Overhead costs represented approximately 30% of these amounts. When physician fees were added, these costs rose to $352 and $467, respectively.

CONCLUSION

Because the overhead costs represent a large proportion of the total costs, allocation methods for these costs should be improved to allow for a more precise determination of the total costs of a colonoscopy. These estimates are useful when analyzing the cost-effectiveness of a strategy that uses colonoscopy when screening for colorectal cancer.

Cost-effectiveness analysis on screening for colorectal neoplasm and management of colorectal cancer in Asia

BACKGROUND

Faecal occult blood testing (FOBT), flexible sigmoidoscopy (FS) and colonoscopy are recommended for subjects above 50 years of age for screening for colorectal cancer (CRC).

AIM

To evaluate the cost-effectiveness of FOBT, FS and colonoscopy on the basis of disease prevalence, compliance rate and cost of screening procedures in Asian countries.

METHODS

A hypothetical population of 100 000 persons aged 50 undergoes either FOBT annually, FS every 5 years or colonoscopy every 10 years until the age of 80 years. Patients with positive FOBT or polyp in FS are offered colonoscopy. Surveillance colonoscopy is repeated every 3 years. The treatment cost of CRC, including surgery and chemotherapy, was evaluated. A Markov model was used to compare the cost-effectiveness of different screening strategies.

RESULTS

Assuming a compliance rate of 90%, colonoscopy, FS and FOBT can reduce CRC incidence by 54.1%, 37.1% and 29.3% respectively. The incremental cost-effectiveness ratio (ICER) for FOBT (US$6222 per life-year saved) is lower than FS (US$8044 per life-year saved) and colonoscopy (US$7211 per life-year saved). When the compliance rate drops to 50% and 30%, FOBT still has the lowest ICER.

CONCLUSION

FOBT is cost-effective compared to FS or colonoscopy for CRC screening in average-risk individuals aged from 50 to 80 years.

What is the value of computered tomography colonography in patients screening positive for fecal occult blood? A systematic review and economic evaluation

BACKGROUND & AIMS

Computerized tomography colonography (CTC) is a highly accurate test for the detection of colorectal polyps and cancers and has been proposed as a potential alternative to colonoscopy. Bowel cancer screening using fecal occult blood testing (FOBT) and follow-up diagnostic colonoscopy is an effective intervention that currently is being implemented in screening programs internationally. Because of high false-positive rates for FOBT, concerns have been raised about patient uptake and access to colonoscopy services. This study assessed the value of CTC as an alternative to colonoscopy in FOBT-positive individuals.

METHODS

A systematic review of studies comparing the accuracy of CTC and colonoscopy for the detection of lesions 10 mm or greater and cancers in nonscreening populations was conducted. A modeled economic analysis was undertaken to assess cost per life-year saved.

RESULTS

Five eligible studies were identified. Pooled sensitivity and specificity for the detection of lesions 10 mm or greater were 63% (95% confidence interval [CI], 55%-71%) and 95% (95% CI, 94%-97%) for CTC, and 95% (95% CI, 90%-98%) and 99.8% (95% CI, 99.5%-100%) for colonoscopy, respectively (3 studies). Pooled sensitivity and specificity for the detection of cancer were 89% (95% CI, 70%-98%) and 97% (95% CI, 95%-98%) for CTC, and 96% (95% CI, 80%-100%) and 99.7% (95% CI, 99%-100%) for colonoscopy, respectively (3 studies). The base case economic analysis showed that CTC is less effective and more costly than colonoscopy. At a low prevalence of polyps, sensitivity analysis found CTC was less effective and less costly than colonoscopy; if CTC was more sensitive than colonoscopy, CTC was more effective, at higher cost.

CONCLUSIONS

Overall, CTC appears less accurate, less effective, and potentially more costly than colonoscopy in individuals with a positive FOBT.

Resource implications for a population-based colorectal cancer screening program in Canada: a study of the impact on colonoscopy capacity and costs in London, Ontario

OBJECTIVE

Cancer Care Ontario has recommended a population-based colorectal cancer (CRC) screening program using fecal occult blood testing. Patients who test positive should undergo further investigation, preferably colonoscopy. So far, no studies have been performed to quantify the costs or demands on the health care system at the community level. The number of consultations, colonoscopies and polypectomies, and the corresponding direct medical costs generated by the CRC screening program, between 2006 and 2015 in London, Ontario, were estimated using a decision analysis model in comparison with the population health model.

METHODS

A faxed survey study was conducted to examine the current CRC screening practice among family physicians in London. Data from the survey and randomized studies were applied to a decision analysis model, which simulated the steps involved in population-based biennial and annual CRC screening between 2006 and 2015. The number of consultations, colonoscopies and polypectomies, and their associated costs were calculated.

RESULTS

For a cohort population of 140,000, between 50 and 74 years of age, in 2006 to 2015, it is estimated that an average of 412 consultations, 463 colonoscopies and 174 polypectomies will be performed per 100,000 screen eligible population per year in biennial screening, and double in annual screening, reflecting an average of 8.7% or 17.6% increase annually in outpatient colonoscopies, respectively, compared with 2003. A mean of $285,000 or $562,000 per year would be required to support the extra consultation and endoscopic procedures generated by the biennial or annual screening.

CONCLUSION

Population-based fecal occult blood testing screening for CRC appears to be a manageable strategy if a modest increase in endoscopic resources is allocated.

A Monotonous Population of Elongated Cells (MPECs) in Colorectal Adenoma Indicates a High Risk of Metachronous Cancer

Accurate predictors for metachronous colorectal cancer (CRC) development after polypectomy are lacking. We evaluated the prognostic value of classical clinicopathologic features and a monotonous population of elongated cells (MPECs) in colorectal adenomas from 171 consecutively selected population-based patients with long-term follow-up. Quantitative image analysis, and univariate and multivariate regression analysis were applied. Ten of 171 adenomas (5.8%) developed metachronous CRC (defined as >24 mo interval and >5 cm from the index adenoma to the cancer). Median follow-up of adenomas with metachronous CRC was 68.4 and without cancer 149.7 months (range: 25 to 192 and 25 to 256, respectively). The most prognostic classical features were the localization of the marker adenoma as proximal (ie, in the cecum through transverse colon) versus distal from the transverse colon [P=0.0003, hazard ratio (HR)=8] and the number of polyps found during colonoscopy (<or=2 vs.>2, P=0.002, HR=6). Quantitative features of the MPECs included the longest nuclear axis and variance of the number of nuclei with 2 neighbors (higher and lower in cancer cases, respectively). Of the 171 adenomas, 50 (29%) had MPECs, of which 9 (18%) patients developed metachronous CRC at follow-up, contrasting 1/121 (0.8%) without MPECs (P=0.0003, HR=23). MPECs occurred in both low-grade and high-grade dysplasia, and in tubular and (tubulo) villous adenomas. MPECs had the strongest predictive value for metachronous CRC development. Adenomas proximally located had additional value but only if they were MPEC positive (which only occurred in 5 adenomas, 3 of which (60%) developed cancer). Having more than 2 polyps also had additional prognostic value but only in MPEC-negative adenomas [10 cases; 1 (10%) developed cancer]. Dysplasia grade and histologic growth pattern had no additional value. Thus, colorectal adenomas with subsequent metachronous cancer development can be identified more accurately with MPECs than with classical prognostic factors.

[Cost-effectiveness of colorectal cancer screening]

Colorectal cancer (CRC) screening in France is based on a faecal occult blood test every two years in average risk subjects 50-74 years of age while other endoscopic or non-endoscopic screening methods are used in Europe and in the USA. Beside the reduced incidence of and mortality from CRC found in available studies, cost-effectiveness data need to be taken into account. Because of the delay between randomized controlled trials and clinical results, transitional probabilistic models of screening programs are useful for public health policy makers. The aim of the present review was to promote the implementation of cost-effectiveness studies, to provide a guide to analyze cost-effectiveness studies on CRC screening and, to propose a French cost effectiveness study comparing CRC screening strategies. Most of these trials were performed by US or UK authors and demonstrate that the incremental cost-effectiveness ratio varies between 5 000 and 15 000 US dollars/one year life gained, with wide variations: these results were highly dependent on the unit costs of the different devices as well as the predictive values of the screening tests. Although CRC screening programs have been implemented in several administrative districts of France since 2002, and the results of these randomized controlled trials using fecal occult blood have been updated, cost-effectiveness criteria need to be integrated; especially since the results of screening campaigns based on other tools such as flexible sigmoidoscopy should be available in 2007.

Extracolonic findings at CT colonography

This review focuses on the detection of extracolonic findings at CT colonography (CTC). Since its introduction, it has been regarded as a promising alternative to conventional colonoscopy for the detection of colorectal polyps and cancers. Unlike conventional colonoscopy and barium enema, CTC allows evaluation not only of the colon but also visualization of the lung bases, the abdomen, and the pelvis. CTC is performed with thin sections (1-5 mm) and small intervals (0.5-2 mm), enabling superb image reconstruction. The ability to evaluate the extracolonic structures can present a clinical dilemma. On the one hand, CTC may incidentally demonstrate asymptomatic malignant diseases or other clinically important conditions, thus possibly reducing morbidity or mortality. On the other hand, CTC may reveal numerous findings of no clinical relevance; this could result in costly additional diagnostic examinations with an increase in morbidity and overall negative impact on patients' health. In this article, extracolonic findings at CTC will be reviewed and the potential benefits and disadvantages will be presented.

Classification and regression tree analysis in public health: methodological review and comparison with logistic regression

BACKGROUND

Audience segmentation strategies are of increasing interest to public health professionals who wish to identify easily defined, mutually exclusive population subgroups whose members share similar characteristics that help determine participation in a health-related behavior as a basis for targeted interventions. Classification and regression tree (C&RT) analysis is a nonparametric decision tree methodology that has the ability to efficiently segment populations into meaningful subgroups. However, it is not commonly used in public health.

PURPOSE

This study provides a methodological overview of C&RT analysis for persons unfamiliar with the procedure.

METHODS AND RESULTS

An example of a C&RT analysis is provided and interpretation of results is discussed. Results are validated with those obtained from a logistic regression model that was created to replicate the C&RT findings. Results obtained from the example C&RT analysis are also compared to those obtained from a common approach to logistic regression, the stepwise selection procedure. Issues to consider when deciding whether to use C&RT are discussed, and situations in which C&RT may and may not be beneficial are described.

CONCLUSIONS

C&RT is a promising research tool for the identification of at-risk populations in public health research and outreach.