Contrasting Effectiveness and Cost-Effectiveness of Colorectal Cancer Screening Under Commercial Insurance vs. Medicare

The Annual Cost of Cancer Screening in the United States

BACKGROUND

Cancer has substantial health, quality-of-life, and economic impacts. Screening may decrease cancer mortality and treatment costs, but the cost of screening in the United States is unknown.

OBJECTIVE

To estimate the annual cost of initial cancer screening (that is, screening without follow-up costs) in the United States in 2021.

DESIGN

Model using national health care survey and cost resources data.

SETTING

U.S. health care systems and institutions.

PARTICIPANTS

People eligible for breast, cervical, colorectal, lung, and prostate cancer screening with available data.

MEASUREMENTS

The number of people screened and associated health care system costs by insurance status in 2021 dollars.

RESULTS

Total health care system costs for initial cancer screenings in the United States in 2021 were estimated at $43 billion. Approximately 88.3% of costs were attributable to private insurance; 8.5% to Medicare; and 3.2% to Medicaid, other government programs, and uninsured persons. Screening for colorectal cancer represented approximately 64% of the total cost; screening colonoscopy represented about 55% of the total. Facility costs (amounts paid to facilities where testing occurred) were major drivers of the total estimated costs of screening.

LIMITATIONS

All data on receipt of cancer screening are based on self-report from national health care surveys. Estimates do not include costs of follow-up for positive or abnormal screening results. Variations in costs based on geography and provider or health care organization are not fully captured.

CONCLUSION

The $43 billion estimated annual cost for initial cancer screening in the United States in 2021 is less than the reported annual cost of cancer treatment in the United States in the first 12 months after diagnosis. Identification of cancer screening costs and their drivers is critical to help inform policy and develop programmatic priorities, particularly for enhancing access to recommended cancer screening services.

PRIMARY FUNDING SOURCE

None.

Effectiveness and Cost-Effectiveness of Colorectal Cancer Screening With a Blood Test That Meets the Centers for Medicare & Medicaid Services Coverage Decision

BACKGROUND & AIMS

A blood-based colorectal cancer (CRC) screening test may increase screening participation. However, blood tests may be less effective than current guideline-endorsed options. The Centers for Medicare & Medicaid Services (CMS) covers blood tests with sensitivity of at least 74% for detection of CRC and specificity of at least 90%. In this study, we investigate whether a blood test that meets these criteria is cost-effective.

METHODS

Three microsimulation models for CRC (MISCAN-Colon, CRC-SPIN, and SimCRC) were used to estimate the effectiveness and cost-effectiveness of triennial blood-based screening (from ages 45 to 75 years) compared to no screening, annual fecal immunochemical testing (FIT), triennial stool DNA testing combined with an FIT assay, and colonoscopy screening every 10 years. The CMS coverage criteria were used as performance characteristics of the hypothetical blood test. We varied screening ages, test performance characteristics, and screening uptake in a sensitivity analysis.

RESULTS

Without screening, the models predicted 77-88 CRC cases and 32-36 CRC deaths per 1000 individuals, costing $5.3-$5.8 million. Compared to no screening, blood-based screening was cost-effective, with an additional cost of $25,600-$43,700 per quality-adjusted life-year gained (QALYG). However, compared to FIT, triennial stool DNA testing combined with FIT, and colonoscopy, blood-based screening was not cost-effective, with both a decrease in QALYG and an increase in costs. FIT remained more effective (+5-24 QALYG) and less costly (-$3.2 to -$3.5 million) than blood-based screening even when uptake of blood-based screening was 20 percentage points higher than uptake of FIT.

CONCLUSION

Even with higher screening uptake, triennial blood-based screening, with the CMS-specified minimum performance sensitivity of 74% and specificity of 90%, was not projected to be cost-effective compared with established strategies for colorectal cancer screening.

Cost-Utility Analysis of Berberine Chemoprevention for Colorectal Cancer After Polypectomy

Background Chemoprevention, such as berberine, has been developed as an alternative or complementary strategy to colonoscopy surveillance and has shown promise in reducing the morbidity and mortality of colorectal cancer. This study aims to evaluate the cost-effectiveness of berberine for postpolypectomy patients from the US third-party payer. Methods A Markov microsimulation model was developed to compare the cost and efficacy of berberine to no intervention, colonoscopy, and the combination of berberine and colonoscopy in postpolypectomy patients. Results After simulating 1 million patients, the study found that colonoscopy alone had a mean cost of $16,391 and mean quality-adjusted life-years (QALYs) of 16.03 per patient, whereas adding berberine slightly reduced the mean cost to $15,609 with a mean QALY of 16.05, making it a dominant strategy. Berberine therapy alone was less effective than colonoscopy alone, with a higher mean cost of $37,480 and a mean QALY of 15.32 per patient. However, berberine therapy was found to be a dominant strategy over no intervention. Conclusions Adding berberine to colonoscopy is the most cost-saving and effective approach for postpolypectomy patients. For patients who refuse or have limited access to colonoscopy, berberine alone is likely to be a dominant strategy compared to no intervention.

Colonoscopy vs the Fecal Immunochemical Test: Which is Best?

Although there is no debate around the effectiveness of colorectal cancer screening in reducing disease burden, there remains a question regarding the most effective and cost-effective screening modality. Current United States guidelines present a panel of options that include the 2 most commonly used modalities, colonoscopy and stool testing with the fecal immunochemical test (FIT). Large-scale comparative effectiveness trials comparing colonoscopy and FIT for colorectal cancer outcomes are underway, but results are not yet available. This review will separately state the "best case" for FIT and colonoscopy as the screening tool of first choice. In addition, the review will examine these modalities from a health economics perspective to provide the reader further context about the relative advantages of these commonly used tests.

Risk-Stratified Screening for Colorectal Cancer Using Genetic and Environmental Risk Factors: A Cost-Effectiveness Analysis Based on Real-World Data

BACKGROUND & AIMS

Previous studies on the cost-effectiveness of personalized colorectal cancer (CRC) screening were based on hypothetical performance of CRC risk prediction and did not consider the association with competing causes of death. In this study, we estimated the cost-effectiveness of risk-stratified screening using real-world data for CRC risk and competing causes of death.

METHODS

Risk predictions for CRC and competing causes of death from a large community-based cohort were used to stratify individuals into risk groups. A microsimulation model was used to optimize colonoscopy screening for each risk group by varying the start age (40-60 years), end age (70-85 years), and screening interval (5-15 years). The outcomes included personalized screening ages and intervals and cost-effectiveness compared with uniform colonoscopy screening (ages 45-75, every 10 years). Key assumptions were varied in sensitivity analyses.

RESULTS

Risk-stratified screening resulted in substantially different screening recommendations, ranging from a one-time colonoscopy at age 60 for low-risk individuals to a colonoscopy every 5 years from ages 40 to 85 for high-risk individuals. Nevertheless, on a population level, risk-stratified screening would increase net quality-adjusted life years gained (QALYG) by only 0.7% at equal costs to uniform screening or reduce average costs by 1.2% for equal QALYG. The benefit of risk-stratified screening improved when it was assumed to increase participation or costs less per genetic test.

CONCLUSIONS

Personalized screening for CRC, accounting for competing causes of death risk, could result in highly tailored individual screening programs. However, average improvements across the population in QALYG and cost-effectiveness compared with uniform screening are small.

Is there a place for sigmoidoscopy in colorectal cancer screening? A systematic review and critical appraisal of cost-effectiveness models

INTRODUCTION

Screening for colorectal cancer (CRC) is effective in reducing both incidence and mortality. Colonoscopy and stool tests are most frequently used for this purpose. Sigmoidoscopy is an alternative screening measure with a strong evidence base. Due to its distinct characteristics, it might be preferred by subgroups. The aim of this systematic review is to analyze the cost-effectiveness of sigmoidoscopy for CRC screening compared to other screening methods and to identify influencing parameters.

METHODS

A systematic literature search for the time frame 01/2010-01/2023 was conducted using the databases MEDLINE, Embase, EconLit, Web of Science, NHS EED, as well as the Cost-Effectiveness Registry. Full economic analyses examining sigmoidoscopy as a screening measure for the general population at average risk for CRC were included. Incremental cost-effectiveness ratios were calculated. All included studies were critically assessed based on a questionnaire for modelling studies.

RESULTS

Twenty-five studies are included in the review. Compared to no screening, sigmoidoscopy is a cost-effective screening strategy for CRC. When modelled as a single measure strategy, sigmoidoscopy is mostly dominated by colonoscopy or modern stool tests. When combined with annual stool testing, sigmoidoscopy in 5-year intervals is more effective and less costly than the respective strategies alone. The results of the studies are influenced by varying assumptions on adherence, costs, and test characteristics.

CONCLUSION

The combination of sigmoidoscopy and stool testing represents a cost-effective screening strategy that has not received much attention in current guidelines. Further research is needed that goes beyond a narrow focus on screening technology and models different, preference-based participation behavior in subgroups.

Effectiveness of Colorectal Cancer (CRC) Screening on All-Cause and CRC-Specific Mortality Reduction: A Systematic Review and Meta-Analysis

(1) Background: The aim of this study was to pool and compare all-cause and colorectal cancer (CRC) specific mortality reduction of CRC screening in randomized control trials (RCTs) and simulation models, and to determine factors that influence screening effectiveness. (2) Methods: PubMed, Embase, Web of Science and Cochrane library were searched for eligible studies. Multi-use simulation models or RCTs that compared the mortality of CRC screening with no screening in general population were included. CRC-specific and all-cause mortality rate ratios and 95% confidence intervals were calculated by a bivariate random model. (3) Results: 10 RCTs and 47 model studies were retrieved. The pooled CRC-specific mortality rate ratios in RCTs were 0.88 (0.80, 0.96) and 0.76 (0.68, 0.84) for guaiac-based fecal occult blood tests (gFOBT) and single flexible sigmoidoscopy (FS) screening, respectively. For the model studies, the rate ratios were 0.45 (0.39, 0.51) for biennial fecal immunochemical tests (FIT), 0.31 (0.28, 0.34) for biennial gFOBT, 0.61 (0.53, 0.72) for single FS, 0.27 (0.21, 0.35) for 10-yearly colonoscopy, and 0.35 (0.29, 0.42) for 5-yearly FS. The CRC-specific mortality reduction of gFOBT increased with higher adherence in both studies (RCT: 0.78 (0.68, 0.89) vs. 0.92 (0.87, 0.98), model: 0.30 (0.28, 0.33) vs. 0.92 (0.51, 1.63)). Model studies showed a 0.62-1.1% all-cause mortality reduction with single FS screening. (4) Conclusions: Based on RCTs and model studies, biennial FIT/gFOBT, single and 5-yearly FS, and 10-yearly colonoscopy screening significantly reduces CRC-specific mortality. The model estimates are much higher than in RCTs, because the simulated biennial gFOBT assumes higher adherence. The effectiveness of screening increases at younger screening initiation ages and higher adherences.

Long-Term Survival and Curative-Intent Treatment in Hepatitis B or C Virus-Associated Hepatocellular Carcinoma Patients Diagnosed during Screening

Background: We initiated a prospective screening trial in patients with hepatitis to diagnose HCC in the early stage and to evaluate the impact on long-term survival. Methods: From 1993−2006, 10,372 patients with chronic hepatitis B (14%), hepatitis C (81%), or both (5%) were enrolled in an HCC screening program. All patients underwent liver biopsy at enrollment. Transabdominal ultrasonography and serum alpha-fetoprotein were evaluated every 6 months. Abnormal screening results led to axial imaging and tumor biopsy. Results: Cirrhosis was confirmed on biopsy in 2074 patients (20%). HCC was diagnosed in 1016 patients (9.8%), all of whom had cirrhosis (49.0% HCC incidence in patients with cirrhosis). HCC was diagnosed at the initial screening in 165 patients (16.2%) and on follow-up in 851 patients (83.8%). The HCC diagnosis median time during follow-up screening was 6 years (range 4−10). Curative-intent treatment (resection, ablation, or transplant) was performed in 713 patients (70.2%). Overall survival at 5 and 10 years in those 713 patients was 30% and 4%, respectively, compared to no 5-year survivors in the 303 patients with advanced-stage disease (p < 0.001). Cause of death at 5 years in the 713 patients treated with curative intent was HCC in 371 patients (52%), progressive cirrhosis in 116 patients (16%), and other causes in 14 patients (2%). At 10 years, 456 patients (64%) had died from HCC, 171 (24%) from progressive cirrhosis, and 57 (8%) from other causes. Conclusions: Our screening program diagnosed early-stage HCC, permitting curative-intent treatment in 70%, but the 10-year survival rate is 4% due to HCC recurrence and progressive cirrhosis.

Do Centers for Medicare and Medicaid Services Quality Measures Reflect Cost-Effectiveness Evidence?

OBJECTIVES

Despite its importance of quality measures used by the Centers for Medicare and Medicaid Services, the underlying cost-effectiveness evidence has not been examined. This study aimed to analyze cost-effectiveness evidence associated with the Centers for Medicare and Medicaid Services quality measures.

METHODS

After classifying 23 quality measures with the Donabedian's structure-process-outcome quality of care model, we identified cost-effectiveness analyses (CEAs) relevant to these measures from the Tufts Medical Center CEA Registry based on the PICOTS (population, intervention, comparator, outcome, time horizon, and setting) framework. We then summarized available incremental cost-effectiveness ratios (ICERs) to determine the cost-effectiveness of the quality measures.

RESULTS

The 23 quality measures were categorized into 14 process, 7 outcome, and 2 structure measures. Cost-effectiveness evidence was only available for 8 of 14 process measures. Two measures (Tobacco Screening and Hemoglobin bA1c Control) were cost-saving and quality-adjusted life-years (QALYs) improving, and 5 (Depression Screening, Influenza Immunization, Colon Cancer Screening, Breast Cancer Screening, and Statin Therapy) were highly cost-effective (median ICER ≤ $50 000/QALY). The remaining measure (Fall Screening) had a median ICER of $120 000/QALY. No CEAs were available for 15 measures: 10 defined by subjective patient ratings and 5 employed outcome measures without specifying an intervention or process.

CONCLUSIONS

When relevant CEAs were available, cost-effectiveness evidence was consistent with quality measures (measures were cost-effective). Nevertheless, most quality measures were based on subjective ratings or outcome measures, posing a challenge in identifying supporting economic evidence. Refining and aligning quality measures with cost-effectiveness evidence can help further improve healthcare efficiency by demonstrating that they are good indicators of both quality and cost-effectiveness of care.

Cost-Effectiveness of Colorectal Cancer Genetic Testing

Colorectal cancer (CRC) remains the second leading cause of cancer-related deaths worldwide. Approximately 3–5% of CRCs are associated with hereditary cancer syndromes. Individuals who harbor germline mutations are at an increased risk of developing early onset CRC, as well as extracolonic tumors. Genetic testing can identify genes that cause these syndromes. Early detection could facilitate the initiation of targeted prevention strategies and surveillance for CRC patients and their families. The aim of this study was to determine the cost-effectiveness of CRC genetic testing. We utilized a cross-sectional design to determine the cost-effectiveness of CRC genetic testing as compared to the usual screening method (iFOBT) from the provider’s perspective. Data on costs and health-related quality of life (HRQoL) of 200 CRC patients from three specialist general hospitals were collected. A mixed-methods approach of activity-based costing, top-down costing, and extracted information from a clinical pathway was used to estimate provider costs. Patients and family members’ HRQoL were measured using the EQ-5D-5L questionnaire. Data from the Malaysian Study on Cancer Survival (MySCan) were used to calculate patient survival. Cost-effectiveness was measured as cost per life-year (LY) and cost per quality-adjusted life-year (QALY). The provider cost for CRC genetic testing was high as compared to that for the current screening method. The current practice for screening is cost-saving as compared to genetic testing. Using a 10-year survival analysis, the estimated number of LYs gained for CRC patients through genetic testing was 0.92 years, and the number of QALYs gained was 1.53 years. The cost per LY gained and cost per QALY gained were calculated. The incremental cost-effectiveness ratio (ICER) showed that genetic testing dominates iFOBT testing. CRC genetic testing is cost-effective and could be considered as routine CRC screening for clinical practice.

Real-world cost-effectiveness of stool-based colorectal cancer screening in a Medicare population

AIM

Multiple screening strategies are guideline-endorsed for average-risk colorectal cancer (CRC). The impact of real-world adherence rates on the cost-effectiveness of non-invasive stool-based CRC screening strategies remains undefined.

METHODS

This cost-effectiveness analysis from the perspective of Medicare as a primary payer used the Colorectal Cancer and Adenoma Incidence and Mortality Microsimulation Model (CRC-AIM) to estimate cost and clinical outcomes for triennial multi-target stool DNA (mt-sDNA), annual fecal immunochemical test (FIT) and annual fecal occult blood test (FOBT) screening strategies in a simulated cohort of US adults aged 65 years, who were assumed to either be previously unscreened or initiating screening upon entry to Medicare. Reported real-world adherence rates for initial stool-based screening and colonoscopy follow up (after a positive stool test result) were defined as 71.1% and 73.0% for mt-sDNA, 42.6% and 47.0% for FIT, and 33.4% and 47.0% for FOBT, respectively. The incremental cost-effectiveness ratio using quality-adjusted life years (QALY) was defined as the primary outcome of interest; other cost and clinical outcomes were also reported in secondary analyses. Multiple sensitivity and scenario analyses were conducted.

RESULTS

When reported real-world adherence rates were included only for initial stool-based screening, mt-sDNA was cost-effective versus FIT ($62,814/QALY) and FOBT ($39,171/QALY); mt-sDNA also yielded improved clinical outcomes. When reported real-world adherence rates were included for both initial stool-based screening and follow-up colonoscopy (when indicated), mt-sDNA was increasingly cost-effective compared to FIT and FOBT ($31,725/QALY and $28,465/QALY, respectively), with further improved clinical outcomes.

LIMITATIONS

Results are based on real-world cross-sectional adherence rates and may vary in the context of other types of settings. Only guideline-recommended stool-based strategies were considered in this analysis.

CONCLUSION

Comparisons of the effectiveness and benefits of specific CRC screening strategies should include both test-specific performance characteristics and real-world adherence to screening tests and, when indicated, follow-up colonoscopy.

Cost-Effectiveness of Current Colorectal Cancer Screening Tests

Cost-effectiveness analysis compares benefits and costs of different interventions to inform decision makers. Alternatives are compared based on an incremental cost-effectiveness ratio reported in terms of cost per quality-adjusted life-year gained. Multiple cost-effectiveness analyses of colorectal cancer (CRC) screening have been performed. Although regional epidemiology of CRC, relevant screening strategies, regional health system, and applicable medical costs in local currencies differ by country and region, several overarching points emerge from literature on cost-effectiveness of CRC screening. Cost-effectiveness analysis informs decisions in ongoing debates, including preferred age to begin average-risk CRC screening, and implementation of CRC screening tailored to predicted CRC risk.

Simulation modeling validity and utility in colorectal cancer screening delivery: A systematic review

OBJECTIVE

This study sought to assess the impact and validity of simulation modeling in informing decision making in a complex area of healthcare delivery: colorectal cancer (CRC) screening.

MATERIALS AND METHODS

We searched 10 electronic databases for English-language articles published between January 1, 2008, and March 1, 2019, that described the development of a simulation model with a focus on average-risk CRC screening delivery. Included articles were reviewed for evidence that the model was validated, and provided real or potential contribution to informed decision making using the GRADE EtD (Grading of Recommendations Assessment, Development, and Evaluation Evidence to Decision) framework.

RESULTS

A total of 43 studies met criteria. The majority used Markov modeling (n = 31 [72%]) and sought to determine cost-effectiveness, compare screening modalities, or assess effectiveness of screening. No study reported full model validation and only (58%) reported conducting any validation. Majority of models were developed to address a specific health systems or policy question; few articles report the model's impact on this decision (n = 39 [91%] vs. n = 5 [12%]). Overall, models provided evidence relevant to every element important to decision makers as outlined in the GRADE EtD framework.

DISCUSSION AND CONCLUSION

Simulation modeling contributes evidence that is considered valuable to decision making in CRC screening delivery, particularly in assessing cost-effectiveness and comparing screening modalities. However, the actual impact on decisions and validity of models is lacking in the literature. Greater validity testing, impact assessment, and standardized reporting of both is needed to understand and demonstrate the reliability and utility of simulation modeling.

Efficacy and cost-effectiveness of fecal immunochemical test versus colonoscopy in colorectal cancer screening: a systematic review and meta-analysis

BACKGROUND AND AIMS

The fecal immunochemical test (FIT) and colonoscopy are the most commonly used strategies for colorectal cancer (CRC) screening worldwide. We aimed to compare their efficacy and cost-effectiveness in CRC screening in an average-risk population.

METHODS

PubMed, Embase, and National Health Services Economic Evaluation Database were searched. Risk ratio (RR) was used to evaluate the differences in detection rates of colorectal neoplasia between FIT and colonoscopy groups. A random-effects model was used to pool RRs. Incremental cost-effectiveness ratios (ICERs) were calculated to evaluate the cost-effectiveness of FIT versus colonoscopy.

RESULTS

Six randomized controlled trials and 17 cost-effectiveness studies were included. The participation rate in the FIT group was higher than that in the colonoscopy group (41.6% vs 21.9%). In the intention-to-treat analysis, FIT had a detection rate of CRC comparable with colonoscopy (RR, .73; 95% confidence interval, .37-1.42) and lower detection rates of any adenoma and advanced adenoma than 1-time colonoscopy. Most included cost-effectiveness studies showed that annual (13/15) or biennial (5/6) FIT was cost-saving (ICER < $0) or very cost-effective ($0 < ICER ≤ $25000/quality-adjusted life-year) compared with colonoscopy every 10 years.

CONCLUSIONS

FIT may be similar to 1-time colonoscopy in the detection rate of CRC, although it has lower detection rates of any adenoma and advanced adenoma than 1-time colonoscopy. Furthermore, annual or biennial FIT appears to be very cost-effective or cost-saving compared with colonoscopy every 10 years. These findings indicate, at least partly, that FIT is noninferior to colonoscopy in CRC screening in an average-risk population. Our findings should be treated with caution and need to be further confirmed.

Strategies for Colorectal Cancer Screening

The incidence of colorectal cancer (CRC) is increasing worldwide. CRC has high mortality when detected at advanced stages, yet it is also highly preventable. Given the difficulties in implementing major lifestyle changes or widespread primary prevention strategies to decrease CRC risk, screening is the most powerful public health tool to reduce mortality. Screening methods are effective but have limitations. Furthermore, many screen-eligible people remain unscreened. We discuss established and emerging screening methods, and potential strategies to address current limitations in CRC screening. A quantum step in CRC prevention might come with the development of new screening strategies, but great gains can be made by deploying the available CRC screening modalities in ways that optimize outcomes while making judicious use of resources.

Cost-Effectiveness of Risk-Stratified Colorectal Cancer Screening Based on Polygenic Risk: Current Status and Future Potential

Background

Although uniform colonoscopy screening reduces colorectal cancer (CRC) mortality, risk-based screening may be more efficient. We investigated whether CRC screening based on polygenic risk is a cost-effective alternative to current uniform screening, and if not, under what conditions it would be.

Methods

The MISCAN-Colon model was used to simulate a hypothetical cohort of US 40-year-olds. Uniform screening was modeled as colonoscopy screening at ages 50, 60, and 70 years. For risk-stratified screening, individuals underwent polygenic testing with current and potential future discriminatory performance (area under the receiver-operating curve [AUC] of 0.60 and 0.65–0.80, respectively). Polygenic testing results were used to create risk groups, for which colonoscopy screening was optimized by varying the start age (40–60 years), end age (70–85 years), and interval (1–20 years).

Results

With current discriminatory performance, optimal screening ranged from once-only colonoscopy at age 60 years for the lowest-risk group to six colonoscopies at ages 40–80 years for the highest-risk group. While maintaining the same health benefits, risk-stratified screening increased costs by $59 per person. Risk-stratified screening could become cost-effective if the AUC value would increase beyond 0.65, the price per polygenic test would drop to less than $141, or risk-stratified screening would lead to a 5% increase in screening participation.

Conclusions

Currently, CRC screening based on polygenic risk is unlikely to be cost-effective compared with uniform screening. This is expected to change with a greater than 0.05 increase in AUC value, a greater than 30% reduction in polygenic testing costs, or a greater than 5% increase in adherence with screening.

Importance of Age-Specific Insurer Perspective on Lifetime Cost Effectiveness of Colorectal Cancer Screening

In "Contrasting Effectiveness and Cost-Effectiveness of Colorectal Cancer (CRC) Screening under Commercial Insurance vs. Medicare", Ladabaum et al. model different CRC screening scenarios that vary the combination of payer, perspective, screening ages, and time horizons. Fecal occult blood testing (FOBT), fecal immunochemical testing (FIT), colonoscopy and flexible sigmoidoscopy were all cost effective compared to no screening, even if initiating or stopping at age 65 years. Assuming perfect adherence, FIT and FOBT were cost saving and dominated colonoscopy. Screening between ages 50 and 64 years appeared relatively costly if only a limited time horizon was considered since the benefits accrue after age 65 years under Medicare.