The cost-effectiveness of CT colonography in screening for colorectal neoplasia

Cost-effectiveness Analysis of Colorectal Cancer Screening Strategies Using Active Learning and Monte Carlo Simulation

INTRODUCTION

Detection of colorectal cancer (CRC) in the early stages through available screening tests increases the patient's survival chances. Multimodal screening policies can benefit patients by providing more diverse screening options and balancing the risks and benefits of screening tests. We investigate the cost-effectiveness of a wide variety of multimodal CRC screening policies.

METHODS

We developed a Monte Carlo simulation framework to model CRC dynamics. We proposed an innovative calibration process using machine learning models to estimate age- and size-specific adenomatous polyps' progression and regression rates. The proposed approach significantly expedites the model parameter space search.

RESULTS

Two multimodal proposed policies (i.e., 1] colonoscopy at 50 y and fecal occult blood test annually between 60 and 75 y and 2] colonoscopy at 50 and 60 y and fecal immunochemical test annually between 70 and 75 y) are identified as efficient frontier policies. Both policies are cost-effective at a willingness to pay of $50,000. Sensitivity analyses were performed to assess the sensitivity of results to a change in screening test costs as well as adherence behavior. The sensitivity analysis results suggest that the proposed policies are mostly robust to the considered changes in screening test costs, as there is a significant overlap between the efficient frontier policies of the baseline and the sensitivity analysis cases. However, the efficient frontier policies were more sensitive to changes in adherence behavior.

CONCLUSION

Generally, combining stool-based tests with visual tests will benefit patients with higher life expectancy and a lower expected cost compared with unimodal screening policies. Colonoscopy at younger ages (when the colonoscopy complication risk is lower) and stool-based tests at older ages are shown to be more effective.

HIGHLIGHTS

We propose a detailed Markov model to capture the colorectal cancer (CRC) dynamics. The proposed Markov model presents the detailed dynamics of adenomas progression to CRC.We use more than 44,000 colonoscopy reports and available data in the literature to calibrate the proposed Markov model using an innovative approach that leverages machine learning models to expedite the calibration process.We investigate the cost-effectiveness of a wide variety of multimodal CRC screening policies and compare their performances with the current in-practice policies.

Calibration and Validation of the Colorectal Cancer and Adenoma Incidence and Mortality (CRC-AIM) Microsimulation Model Using Deep Neural Networks

OBJECTIVES

Machine learning (ML)-based emulators improve the calibration of decision-analytical models, but their performance in complex microsimulation models is yet to be determined.

METHODS

We demonstrated the use of an ML-based emulator with the Colorectal Cancer (CRC)-Adenoma Incidence and Mortality (CRC-AIM) model, which includes 23 unknown natural history input parameters to replicate the CRC epidemiology in the United States. We first generated 15,000 input combinations and ran the CRC-AIM model to evaluate CRC incidence, adenoma size distribution, and the percentage of small adenoma detected by colonoscopy. We then used this data set to train several ML algorithms, including deep neural network (DNN), random forest, and several gradient boosting variants (i.e., XGBoost, LightGBM, CatBoost) and compared their performance. We evaluated 10 million potential input combinations using the selected emulator and examined input combinations that best estimated observed calibration targets. Furthermore, we cross-validated outcomes generated by the CRC-AIM model with those made by CISNET models. The calibrated CRC-AIM model was externally validated using the United Kingdom Flexible Sigmoidoscopy Screening Trial (UKFSST).

RESULTS

The DNN with proper preprocessing outperformed other tested ML algorithms and successfully predicted all 8 outcomes for different input combinations. It took 473 s for the trained DNN to predict outcomes for 10 million inputs, which would have required 190 CPU-years without our DNN. The overall calibration process took 104 CPU-days, which included building the data set, training, selecting, and hyperparameter tuning of the ML algorithms. While 7 input combinations had acceptable fit to the targets, a combination that best fits all outcomes was selected as the best vector. Almost all of the predictions made by the best vector laid within those from the CISNET models, demonstrating CRC-AIM's cross-model validity. Similarly, CRC-AIM accurately predicted the hazard ratios of CRC incidence and mortality as reported by UKFSST, demonstrating its external validity. Examination of the impact of calibration targets suggested that the selection of the calibration target had a substantial impact on model outcomes in terms of life-year gains with screening.

CONCLUSIONS

Emulators such as a DNN that is meticulously selected and trained can substantially reduce the computational burden of calibrating complex microsimulation models.

HIGHLIGHTS

Calibrating a microsimulation model, a process to find unobservable parameters so that the model fits observed data, is computationally complex.We used a deep neural network model, a popular machine learning algorithm, to calibrate the Colorectal Cancer Adenoma Incidence and Mortality (CRC-AIM) model.We demonstrated that our approach provides an efficient and accurate method to significantly speed up calibration in microsimulation models.The calibration process successfully provided cross-model validation of CRC-AIM against 3 established CISNET models and also externally validated against a randomized controlled trial.

Identifying a Single Optimal Integrated Cervical Cancer Prevention Policy in Norway: A Cost-Effectiveness Analysis

BACKGROUND

Interventions targeting the same disease but at different points along the disease continuum (e.g., screening and vaccination to prevent cervical cancer [CC]) are often evaluated in isolation, which can affect cost-effectiveness profiles and policy conclusions. We evaluated nonavalent human papillomavirus (HPV) vaccine (9vHPV) compared with bivalent HPV vaccine (2vHPV) alongside deintensified screening intervals for a vaccinated birth cohort to inform a single optimal integrated CC prevention policy.

METHODS

Using a multimodeling approach, we evaluated the health and economic impacts of alternative CC screening strategies for a Norwegian birth cohort eligible for HPV vaccination in 2021 assuming they received 1) 2vHPV or 2) 9vHPV. We conducted 1) a restricted analysis that evaluated the optimal HPV vaccine under current screening guidelines; and 2) a comprehensive analysis including alternative screening and vaccination strategy combinations. We calculated incremental cost-effectiveness ratios (ICERs) and evaluated them according to different cost-effectiveness thresholds.

RESULTS

Assuming a cost-effectiveness threshold of $40,000 per quality-adjusted life year (QALY) gained, we found that, while holding screening intensity fixed, switching the routine vaccination program in Norway from 2vHPV to 9vHPV would not be considered cost-effective (ICER of $132,700 per QALY gained). However, when allowing for varying intensities of CC screening, we found that switching to 9vHPV would be cost-effective compared with 2vHPV under an alternative threshold of $55,000 per QALY gained, if coupled with reductions in the number of lifetime screens.

CONCLUSIONS

Our analysis highlights the importance of evaluating the full potential policy landscape for country-level decision makers considering policy adoption, including nonindependent primary and secondary prevention efforts, to draw appropriate conclusions and avoid sub-optimal outcomes.

HIGHLIGHTS

Without evaluating the full potential policy landscape, including primary and secondary prevention efforts, country-level decision makers may not be able to draw appropriate policy conclusions, resulting in suboptimal outcomes.An applied example from cervical cancer prevention in Norway compared a restricted analysis of current screening guidelines to a comprehensive analysis including alternative screening and vaccination strategy combinations.We found that a switch from bivalent to nonavalent human papillomavirus vaccine would be considered cost-effective in Norway if coupled with reductions in the number of lifetime screens compared with the current screening strategy.A comprehensive analysis that considers how different types of interventions along the disease continuum affect each other will be critical for decision makers interpreting cost-effectiveness analysis results.

Cost of Increasing Years-of-Life-Gained (YLG) Using Fecal Immunochemical Testing as a Population-Level Screening Model in a Rural Appalachian Population

PURPOSE

Given the innovation of fecal immunochemical testing (FIT) to detect polyps in the rectum and colon for removal by colonoscopy, it is important to determine the cost per Life-Year Gained (LYG) when using FIT as a population-level screening model. This is particularly true for medically underserved rural populations. Accordingly, the purpose of this study was to make this determination among rural Appalachians experiencing isolation and economic challenges.

METHODS

The study occurred in an 8-county area of southeastern Kentucky. Kits were distributed to 1,424 residents. Seven hundred thirty-two kits (51.4%) were completed and returned. A Markov decision-analytic model was developed using PrecisionTree 7.6.

FINDINGS

Reactive test results occurred for 144 of the completed kits (19.7%). Thirty-seven colonoscopies were verified, with 15 of these indicating precancerous changes or actual cancer. Program costs were estimated at $461,952, with the average cost per person screened estimated at $324. Cost per LYG was $7,912.

CONCLUSIONS

In contrast to an average cost per LYG of $17,200, our findings suggest a highly favorable cost-effectiveness ratio for this population of medically underserved rural residents. Cost-benefit analyses suggest that the screening program begins to yield positive net benefits at the stage when project recipients undergo colonoscopy, suggesting that this is the key step for behavioral intervention and intensified outreach.

Critical Analysis of Markov Models Used for the Economic Evaluation of Colorectal Cancer Screening: A Systematic Review

BACKGROUND

The economic evaluation of colorectal cancer screening is challenging because of the need to model the underlying unobservable natural history of the disease.

OBJECTIVES

To describe the available Markov models and to critically analyze their main structural assumptions.

METHODS

A systematic search was performed in eight relevant databases (MEDLINE, Embase, Econlit, National Health Service Economic Evaluation Database, Health Economic Evaluations Database, Health Technology Assessment database, Cost-Effective Analysis Registry, and European Network of Health Economics Evaluation Databases), identifying 34 models that met the inclusion criteria. A comparative analysis of model structure and parameterization was conducted using two checklists and guidelines for cost-effectiveness screening models.

RESULTS

Two modeling techniques were identified. One strategy used a Markov model to reproduce the natural history of the disease and an overlaying model that reproduced the screening process, whereas the other used a single model to represent a screening program. Most of the studies included only adenoma-carcinoma sequences, a few included de novo cancer, and none included the serrated pathway. Parameterization of adenoma dwell time, sojourn time, and surveillance differed between studies, and there was a lack of validation and statistical calibration against local epidemiological data. Most of the studies analyzed failed to perform an adequate literature review and synthesis of diagnostic accuracy properties of the screening tests modeled.

CONCLUSIONS

Several strategies to model colorectal cancer screening have been developed, but many challenges remain to adequately represent the natural history of the disease and the screening process. Structural uncertainty analysis could be a useful strategy for understanding the impact of the assumptions of different models on cost-effectiveness results.

Cost-effectiveness of colorectal cancer screening in Ukraine

Background

Colorectal cancer is one of the most common cancers worldwide and is associated with high mortality when detected at a later stage. There is a paucity of studies from low and middle income countries to support the cost-effectiveness of colorectal cancer screening. We aim to analyze the cost-effectiveness of colorectal cancer screening compared to no screening in Ukraine, a lower-middle income country.

Methods

We developed a deterministic Markov cohort model to assess the cost-effectiveness of three colorectal cancer screening strategies [fecal occult blood test (FOBT) every year, flexible sigmoidoscopy with FOBT every 5 years, and colonoscopy every 10 years] compared to no screening. We modeled outcomes in terms of cost per quality-adjusted life-years (QALYs) over a lifetime time horizon. We performed sensitivity analyses on treatment adherence, test characteristics and costs. Analyses were conducted from the perspective of the Ministry of Health of Ukraine.

Results

The base-case lifetime cost-effectiveness analysis showed that all three screening strategies were cost saving compared to no screening, and among the three strategies, colonoscopy every 10 years was the dominant strategy compared to no screening with standard adherence to treatment. When decreased adherence to treatment was modeled, colonoscopy every 10 years was the most cost-effective strategy with an incremental cost-effectiveness ratio of $843 per QALY compared with no screening.

Conclusion

Our findings indicate that colorectal cancer screening can save money and improve health compared to no screening in Ukraine. Colonoscopy every 10 years is superior to the other screening modalities evaluated in this study. This knowledge can be used to concentrate efforts on developing a national screening program in Ukraine.

International variation in the prevalence of preclinical colorectal cancer: Implications for predictive values of noninvasive screening tests and potential target populations for screening

Screening for colorectal cancer (CRC) is implemented in an increasing number of countries. We aimed to assess international variation in the prevalence of preclinical CRC and the resulting variation in positive and negative predictive values (PPVs, NPVs) of existing and potential CRC screening tests in various countries. Using age‐ and sex‐specific CRC incidence data and transition rates from preclinical to clinical CRC we estimated overall and age‐ and sex‐specific prevalence of preclinical CRC in the target population aged 50–74 years in different parts of the world. These prevalence estimates were used to derive PPVs and NPVs for existing and potential noninvasive screening tests with varying levels of sensitivity and specificity. Within all regions and countries, prevalence strongly increases with age and is higher in men than in women. In addition, major variation was seen between regions and countries, with overall prevalence varying between 1 and 0.1%. As a result, PPVs are expected to strongly vary between ∼10% for men in high incidence countries, such as Australia and Germany, and 1% for women in low incidence countries, whereas NPVs are expected to be consistently well above 99%. Variation in CRC prevalence profoundly affects expected PPVs of screening tests, and PPVs should be carefully considered when decisions on screening tests and strategies are made for specific populations and health care systems. Here, we provide estimates of preclinical CRC and expected PPVs and NPVs of noninvasive screening tests, which may enhance the empirical basis for planning of population‐based CRC screening strategies.

What's new?

Colorectal cancer (CRC) screening is implemented in an increasing number of countries, usually in a two‐step approach consisting in a noninvasive test followed by colonoscopy in case of a positive result. Prevalence of preclinical colorectal cancer strongly affects screening efficiency, but such data is scarce. Here, the authors provide detailed age‐ and sex‐specific preclinical CRC prevalence estimates for various countries and geographical regions and show their implications on expected positive and negative predictive values of existing and potential noninvasive screening tests. Knowledge of these predictive values should enhance the empirical basis for decisions on CRC screening tests and target populations.

Costs of colorectal cancer screening provision in CDC's Colorectal Cancer Control Program: Comparisons of colonoscopy and FOBT/FIT based screening

We assess annual costs of screening provision activities implemented by 23 of the Centers for Disease Control and Prevention's Colorectal Cancer Control Program (CRCCP) grantees and report differences in costs between colonoscopy and FOBT/FIT-based screening programs. We analysed annual cost data for the first three years of the CRCCP (July 2009-June 2011) for each screening provision activity and categorized them into clinical and non-clinical screening provision activities. The largest cost components for both colonoscopy and FOBT/FIT-based programs were screening and diagnostic services, program management, and data collection and tracking. During the first 3 years of the CRCCP, the average annual clinical cost for screening and diagnostic services per person served was $1150 for colonoscopy programs, compared to $304 for FIT/FOBT-based programs. Overall, FOBT/FIT-based programs appear to have slightly higher non-clinical costs per person served (average $1018; median $838) than colonoscopy programs (average $980; median $686). Colonoscopy-based CRCCP programs have higher clinical costs than FOBT/FIT-based programs during the 3-year study timeframe (translating into fewer people screened). Non-clinical costs for both approaches are similar and substantial. Future studies of the cost-effectiveness of colorectal cancer screening initiatives should consider both clinical and non-clinical costs.

Cost-effectiveness of alternative colonoscopy surveillance strategies to mitigate metachronous colorectal cancer incidence

BACKGROUND

The incidence of metachronous colorectal cancer (MCRC) among colorectal cancer (CRC) survivors varies significantly, and the optimal colonoscopy surveillance practice for mitigating MCRC incidence is unknown.

METHODS

A cost-effectiveness analysis was used to compare the performances of the US Multi-Society Task Force guideline and all clinically reasonable colonoscopy surveillance strategies for 50- to 79-year-old posttreatment CRC patients with a computer simulation model.

RESULTS

The US guideline [(1,3,5)] recommends the first colonoscopy 1 year after treatment, whereas the second and third colonoscopies are to be repeated at 3- and 5-year intervals. Some promising alternative cost-effective strategies were identified. In comparison with the US guideline, under various scenarios for a 20-year period, 1) reducing the surveillance interval of the guideline after the first colonoscopy by 1 year [(1,2,5)] would save up to 78 discounted life-years (LYs) and prevent 23 MCRCs per 1000 patients (incremental cost-effectiveness ratio [ICER] ≤ $23,270/LY), 2) reducing the intervals after the first and second negative colonoscopies by 1 year [(1,2,4)] would save/prevent up to 109 discounted LYs and 36 MCRCs (ICER ≤ $52,155/LY), and 3) reducing the surveillance intervals after the first and second negative colonoscopy by 1 and 2 years [(1,2,3)] would save/prevent up to 141 discounted LYs and 50 MCRCs (ICER ≤ $63,822/LY). These strategies would require up to 1100 additional colonoscopies per 1000 patients. Although the US guideline might not be cost-effective in comparison with a less intensive oncology guideline [(3,3,5); the ICER could be as high as $140,000/LY], the promising strategies would be cost-effective in comparison with such less intensive guidelines unless the cumulative MCRC incidence were very low.

CONCLUSIONS

The US guideline might be improved by a slight increase in the surveillance intensity at the expense of moderately increased cost. More research is warranted to explore the benefits/harms of such practices. Cancer 2016;122:2560-70. © 2016 American Cancer Society.

Cost Effectiveness of Colorectal Cancer Screening Strategies

BACKGROUND

Several screening tests are available to detect colorectal cancer (CRC) and reduce the incidence and mortality of CRC. The purpose of this review was to determine how current CRC screening strategies for CRC compare with no screening and whether agreement exists with regard to the cost effectiveness of different strategies.

METHODS

Databases were searched for cost-effectiveness analyses focused on CRC screening strategies in the United States and published between May 2007 and February 2014. We analyzed the uses of fecal occult blood, fecal immunochemistry, and stool DNA tests, as well as sigmoidoscopy, colonoscopy, and virtual colonoscopy. A paired comparison of each screening strategy with no screening across each of the studies reviewed was conducted. A series of paired comparisons of the results reported in each of the studies is also included.

RESULTS

When compared with no screening, all CRC screening strategies evaluated in this review were cost effective. There was disagreement as to which screening strategy was the most cost effective. However, sigmoidoscopy combined with fecal blood testing always dominated either strategy alone. Studies comparing colonoscopy with fecal blood testing, sigmoidoscopy, or both had mixed results.

CONCLUSIONS

Compared with no screening, all CRC screening strategies are more cost effective. Study results disagree as to which screening strategy should be the preferred method.

Willingness to Pay for CT Colonography: A Survey of Patient Preferences

OBJECTIVE

CT colonography (CTC) has received mixed reviews both in the radiology literature and in clinical practice. CTC is less invasive than optical colonoscopy (OC), is better for identifying polyps, and does not require sedation. However, its cost-effectiveness has been called into question, and there is a residual need for OC if the CTC findings are positive. Some radiologists are hesitant to perform CTC because of the time-intensive nature of its interpretation. Results of willingness-to-pay surveys can be informative about preferences and value placed on intangibles. The purpose of this study was to use such a survey to elicit the preferences of radiologists about CTC versus OC.

SUBJECTS AND METHODS

A vignette was presented in which the insurer covered OC at no charge but required out-of-pocket payment for CTC. The strengths and weaknesses of OC and CTC were listed. The respondents were asked how much they would be willing to pay for CTC; for CTC with perfect sensitivity, specificity, and accuracy; and for CTC that required no bowel preparation.

RESULTS

Twenty-eight of 42 radiologists preferred OC to CTC. One radiologist was indifferent. Four radiologists would reverse their preference and choose CTC if it had 100% sensitivity. Sixteen radiologists said they would prefer CTC if it had 100% specificity. If CTC eliminated the need for bowel preparation, 57% would prefer it to OC. Thirty-one (74%) radiologists preferred perfect sensitivity to perfect specificity.

CONCLUSION

Despite the less invasive nature of CTC, most radiologists who responded to the survey preferred OC for colorectal cancer screening, mostly because of the definitive nature of OC due to the capability of immediate biopsy of suspicious lesions and the lack of requirement for a second round of bowel preparation.

Optimal use of colonoscopy and fecal immunochemical test for population-based colorectal cancer screening: a cost-effectiveness analysis using Japanese data

OBJECTIVE

There have been few cost-effectiveness analyses of population-based colorectal cancer screening in Japan, and there is no consensus on the optimal use of total colonoscopy and the fecal immunochemical test for colorectal cancer screening with regard to cost-effectiveness and total colonoscopy workload. The present study aimed to examine the cost-effectiveness of colorectal cancer screening using Japanese data to identify the optimal use of total colonoscopy and fecal immunochemical test.

METHODS

We developed a Markov model to assess the cost-effectiveness of colorectal cancer screening offered to an average-risk population aged 40 years or over. The cost, quality-adjusted life-years and number of total colonoscopy procedures required were evaluated for three screening strategies: (i) a fecal immunochemical test-based strategy; (ii) a total colonoscopy-based strategy; (iii) a strategy of adding population-wide total colonoscopy at 50 years to a fecal immunochemical test-based strategy.

RESULTS

All three strategies dominated no screening. Among the three, Strategy 1 was dominated by Strategy 3, and the incremental cost per quality-adjusted life-years gained for Strategy 2 against Strategies 1 and 3 were JPY 293 616 and JPY 781 342, respectively. Within the Japanese threshold (JPY 5-6 million per QALY gained), Strategy 2 was the most cost-effective, followed by Strategy 3; however, Strategy 2 required more than double the number of total colonoscopy procedures than the other strategies.

CONCLUSIONS

The total colonoscopy-based strategy could be the most cost-effective for population-based colorectal cancer screening in Japan. However, it requires more total colonoscopy procedures than the other strategies. Depending on total colonoscopy capacity, the strategy of adding total colonoscopy for individuals at a specified age to a fecal immunochemical test-based screening may be an optimal solution.

Beware of Kinked Frontiers: A Systematic Review of the Choice of Comparator Strategies in Cost-Effectiveness Analyses of Human Papillomavirus Testing in Cervical Screening

OBJECTIVES

To systematically review the choice of comparator strategies in cost-effectiveness analyses (CEAs) of human papillomavirus testing in cervical screening.

METHODS

The PubMed, Web of Knowledge, and Scopus databases were searched to identify eligible model-based CEAs of cervical screening programs using human papillomavirus testing. The eligible CEAs were reviewed to investigate what screening strategies were chosen for analysis and how this choice might have influenced estimates of the incremental cost-effectiveness ratio (ICER). Selected examples from the reviewed studies are presented to illustrate how the omission of relevant comparators might influence estimates of screening cost-effectiveness.

RESULTS

The search identified 30 eligible CEAs. The omission of relevant comparator strategies appears likely in 18 studies. The ICER estimates in these cases are probably lower than would be estimated had more comparators been included. Five of the 30 studies restricted relevant comparator strategies to sensitivity analyses or other subanalyses not part of the principal base-case analysis. Such exclusion of relevant strategies from the base-case analysis can result in cost-ineffective strategies being identified as cost-effective.

CONCLUSIONS

Many of the CEAs reviewed appear to include insufficient comparator strategies. In particular, they omit strategies with relatively long screening intervals. Omitting relevant comparators matters particularly if it leads to the underestimation of ICERs for strategies around the cost-effectiveness threshold because these strategies are the most policy relevant from the CEA perspective. Consequently, such CEAs may not be providing the best possible policy guidance and lead to the mistaken adoption of cost-ineffective screening strategies.

Cost-effectiveness simulation and analysis of colorectal cancer screening in Hong Kong Chinese population: comparison amongst colonoscopy, guaiac and immunologic fecal occult blood testing

Background

The aim of this study was to evaluate the cost-effectiveness of CRC screening strategies from the healthcare service provider perspective based on Chinese population.

Methods

A Markov model was constructed to compare the cost-effectiveness of recommended screening strategies including annual/biennial guaiac fecal occult blood testing (G-FOBT), annual/biennial immunologic FOBT (I-FOBT), and colonoscopy every 10 years in Chinese aged 50 year over a 25-year period. External validity of model was tested against data retrieved from published randomized controlled trials of G-FOBT. Recourse use data collected from Chinese subjects among staging of colorectal neoplasm were combined with published unit cost data ($USD in 2009 price values) to estimate a stage-specific cost per patient. Quality-adjusted life-years (QALYs) were quantified based on the stage duration and SF-6D preference-based value of each stage. The cost-effectiveness outcome was the incremental cost-effectiveness ratio (ICER) represented by costs per life-years (LY) and costs per QALYs gained.

Results

In base-case scenario, the non-dominated strategies were annual and biennial I-FOBT. Compared with no screening, the ICER presented $20,542/LYs and $3155/QALYs gained for annual I-FOBT, and $19,838/LYs gained and $2976/QALYs gained for biennial I-FOBT. The optimal screening strategy was annual I-FOBT that attained the highest ICER at the threshold of $50,000 per LYs or QALYs gained.

Conclusion

The Markov model informed the health policymakers that I-FOBT every year may be the most effective and cost-effective CRC screening strategy among recommended screening strategies, depending on the willingness-to-pay of mass screening for Chinese population.

Trial registration

ClinicalTrials.gov Identifier NCT02038283

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1730-y) contains supplementary material, which is available to authorized users.

Cost Differences After Initial CT Colonography Versus Optical Colonoscopy in the Elderly

RATIONALE AND OBJECTIVES

To compare differences in Medicare costs 1 year after initial computed tomographic colonography (CTC) or initial optical colonoscopy (OC).

MATERIALS AND METHODS

We performed a retrospective cohort study of asymptomatic Medicare outpatients aged ≥ 66 years who received initial CTC (n = 531) or OC (n = 17,593) between January 2007 and December 2008; initial OC patients were matched on county of residence and year of screening. Outcomes included differences in total inpatient and outpatient Medicare costs 1 year after initial CTC or OC and differences in outpatient testing of potential findings in the colon, abdomen, pelvis, and lungs.

RESULTS

Higher adjusted costs per patient were revealed in the year after initial CTC compared to initial OC for outpatient testing related to potential colonic ($50; 95% confidence interval [CI], $12-$88; P = .010) and extracolonic findings ($64; 95% CI, $23-$106; P = .002). However, there were no differences in adjusted total costs per patient in the year after either modality ($2065; 95% CI, $1672-$5803; P = .28). Similarly, adjusted costs did not differ between cohorts for inpatient ($267; 95% CI, $1017-$1550; P = .68) or outpatient care ($2828; 95% CI, $311-$5966; P = .08).

CONCLUSIONS

Despite higher adjusted costs of outpatient testing potentially related to colonic and extracolonic findings among asymptomatic elderly patients 1 year after initial CTC compared to OC, we found no differences in adjusted total, inpatient, or outpatient costs between cohorts. Although Medicare does not cover screening CTC, our results suggest that these modalities generate comparable downstream costs to payers.

Computed tomographic colonography compared with colonoscopy or barium enema for diagnosis of colorectal cancer in older symptomatic patients: two multicentre randomised trials with economic evaluation (the SIGGAR trials)

BACKGROUND

Computed tomographic colonography (CTC) is a relatively new diagnostic test that may be superior to existing alternatives to investigate the large bowel.

OBJECTIVES

To compare the diagnostic efficacy, acceptability, safety and cost-effectiveness of CTC with barium enema (BE) or colonoscopy.

DESIGN

Parallel randomised trials: BE compared with CTC and colonoscopy compared with CTC (randomisation 2 : 1, respectively).

SETTING

A total of 21 NHS hospitals.

PARTICIPANTS

Patients aged ≥ 55 years with symptoms suggestive of colorectal cancer (CRC).

INTERVENTIONS

CTC, BE and colonoscopy.

MAIN OUTCOME MEASURES

For the trial of CTC compared with BE, the primary outcome was the detection rate of CRC and large polyps (≥ 10 mm), with the proportion of patients referred for additional colonic investigation as a secondary outcome. For the trial of CTC compared with colonoscopy, the primary outcome was the proportion of patients referred for additional colonic investigation, with the detection rate of CRC and large polyps as a secondary outcome. Secondary outcomes for both trials were miss rates for cancer (via registry data), all-cause mortality, serious adverse events, patient acceptability, extracolonic pathology and cost-effectiveness.

RESULTS

A total of 8484 patients were registered and 5384 were randomised and analysed (BE trial: 2527 BE, 1277 CTC; colonoscopy trial: 1047 colonoscopy, 533 CTC). Detection rates in the BE trial were 7.3% (93/1277) for CTC, compared with 5.6% (141/2527) for BE (p = 0.0390). The difference was due to better detection of large polyps by CTC (3.6% vs. 2.2%; p = 0.0098), with no significant difference for cancer (3.7% vs. 3.4%; p = 0.66). Significantly more patients having CTC underwent additional investigation (23.5% vs. 18.3%; p = 0.0003). At the 3-year follow-up, the miss rate for CRC was 6.7% for CTC (three missed cancers) and 14.1% for BE (12 missed cancers). Significantly more patients randomised to CTC than to colonoscopy underwent additional investigation (30% vs. 8.2%; p < 0.0001). There was no significant difference in detection rates for cancer or large polyps (10.7% for CTC vs. 11.4% for colonoscopy; p = 0.69), with no difference when cancers (p = 0.94) and large polyps (p = 0.53) were analysed separately. At the 3-year follow-up, the miss rate for cancer was nil for colonoscopy and 3.4% for CTC (one missed cancer). Adverse events were uncommon for all procedures. In 1042 of 1748 (59.6%) CTC examinations, at least one extracolonic finding was reported, and this proportion increased with age (p < 0.0001). A total of 149 patients (8.5%) were subsequently investigated, and extracolonic neoplasia was diagnosed in 79 patients (4.5%) and malignancy in 29 (1.7%). In the short term, CTC was significantly more acceptable to patients than BE or colonoscopy. Total costs for CTC and colonoscopy were finely balanced, but CTC was associated with higher health-care costs than BE. The cost per large polyp or cancer detected was £4235 (95% confidence interval £395 to £9656).

CONCLUSIONS

CTC is superior to BE for detection of cancers and large polyps in symptomatic patients. CTC and colonoscopy detect a similar proportion of large polyps and cancers and their costs are also similar. CTC precipitates significantly more additional investigations than either BE or colonoscopy, and evidence-based referral criteria are needed. Further work is recommended to clarify the extent to which patients initially referred for colonoscopy or BE undergo subsequent abdominopelvic imaging, for example by computed tomography, which will have a significant impact on health economic estimates.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN95152621.

CT colonography: accuracy, acceptance, safety and position in organised population screening

Colorectal cancer (CRC) is the second most common cancer and second most common cause of cancer-related deaths in Europe. The introduction of CRC screening programmes using stool tests and flexible sigmoidoscopy, have been shown to reduce CRC-related mortality substantially. In several European countries, population-based CRC screening programmes are ongoing or being rolled out. Stool tests like faecal occult blood testing are non-invasive and simple to perform, but are primarily designed to detect early invasive cancer. More invasive tests like colonoscopy and CT colonography (CTC) aim at accurately detecting both CRC and cancer precursors, thus providing for cancer prevention. This review focuses on the accuracy, acceptance and safety of CTC as a CRC screening technique and on the current position of CTC in organised population screening. Based on the detection characteristics and acceptability of CTC screening, it might be a viable screening test. The potential disadvantage of radiation exposure is probably overemphasised, especially with newer technology. At this time-point, it is not entirely clear whether the detection of extracolonic findings at CTC is of net benefit and is cost effective, but with responsible handling, this may be the case. Future efforts will seek to further improve the technique, refine appropriate diagnostic algorithms and study cost-effectiveness.

Costs of planning and implementing the CDC's Colorectal Cancer Screening Demonstration Program

BACKGROUND

The Centers for Disease Control and Prevention (CDC) initiated the Colorectal Cancer Screening Demonstration Program (CRCSDP) to explore the feasibility of establishing a large-scale colorectal cancer screening program for underserved populations in the United States. The authors of the current report provide a detailed description of the total program costs (clinical and nonclinical) incurred during both the start-up and service delivery (screening) phases of the 4-year program.

METHODS

Tailored cost questionnaires were completed by staff at the 5 CRCSDP sites. Cost data were collected for clinical services and nonclinical programmatic activities (program management, data collection, and tracking, etc). In-kind contributions also were measured and were assigned monetary values.

RESULTS

Nearly $11.3 million was expended by the 5 sites over 4 years, and 71% was provided by the CDC. The proportion of funding spent on clinical service delivery and service delivery/patient support comprised the largest proportion of cost during the implementation phase (years 2-4). The per-person nonclinical cost comprised a substantial portion of total costs for all sites. The cost per person screened varied across the 5 sites and by screening method. Overall, economies of scale were observed, with lower costs resulting from larger numbers of individuals screened.

CONCLUSIONS

Programs incur substantial variable costs related to clinical services and semivariable costs related to nonclinical services. Therefore, programs that serve large populations are likely to achieve a lower cost per person.

Economic evaluation of colorectal cancer (CRC) screening

Because of its incidence and mortality colorectal cancer represents a serious public health issue in industrial countries. In order to reduce its social impact a number of screening strategies have been implemented, which allow an early diagnosis and treatment. These basically include faecal tests and studies that directly explore the colon and rectum. No strategy, whether alone or combined, has proven definitively more effective than the rest, but any such strategy is better than no screening at all. Selecting the most efficient strategy for inclusion in a population-wide program is an uncertain choice. Here we review the evidence available on the various economic evaluations, and conclude that no single method has been clearly identified as most cost-effective; further research in this setting is needed once common economic evaluation standards are established in order to alleviate the methodological heterogeneity prevailing in study results.

Review of economic evidence in the prevention and early detection of colorectal cancer

This paper aims to systematically review the cost-effectiveness evidence, and to provide a critical appraisal of the methods used in the model-based economic evaluation of CRC screening and subsequent surveillance. A search strategy was developed to capture relevant evidence published 1999-November 2012. Databases searched were MEDLINE, EMBASE, National Health Service Economic Evaluation (NHS EED), EconLit, and HTA. Full economic evaluations that considered costs and health outcomes of relevant intervention were included. Sixty-eight studies which used either cohort simulation or individual-level simulation were included. Follow-up strategies were mostly embedded in the screening model. Approximately 195 comparisons were made across different modalities; however, strategies modelled were often simplified due to insufficient evidence and comparators chosen insufficiently reflected current practice/recommendations. Studies used up-to-date evidence on the diagnostic test performance combined with outdated information on CRC treatments. Quality of life relating to follow-up surveillance is rare. Quality of life relating to CRC disease states was largely taken from a single study. Some studies omitted to say how identified adenomas or CRC were managed. Besides deterministic sensitivity analysis, probabilistic sensitivity analysis (PSA) was undertaken in some studies, but the distributions used for PSA were rarely reported or justified. The cost-effectiveness of follow-up strategies among people with confirmed adenomas are warranted in aiding evidence-informed decision making in response to the rapidly evolving technologies and rising expectations.

An international review of the main cost-effectiveness drivers of virtual colonography versus conventional colonoscopy for colorectal cancer screening: is the tide changing due to adherence?

OBJECTIVES

The majority of recent cost-effectiveness reviews concluded that computerised tomographic colonography (CTC) is not a cost-effective colorectal cancer (CRC) screening strategy yet. The objective of this review is to examine cost-effectiveness of CTC versus optical colonoscopy (COL) for CRC screening and identify the main drivers influencing cost-effectiveness due to the emergence of new research.

METHODS

A systematic review was conducted for cost-effectiveness studies comparing CTC and COL as a screening tool and providing outcomes in life-years saved, published between January 2006 and November 2012.

RESULTS

Nine studies were included in the review. There was considerable heterogeneity in modelling complexity and methodology. Different model assumptions and inputs had large effects on resulting cost-effectiveness of CTC and COL. CTC was found to be dominant or cost-effective in three studies, assuming the most favourable scenario. COL was found to be not cost effective in one study.

CONCLUSIONS

CTC has the potential to be a cost-effective CRC screening strategy when compared to COL. The most important assumptions that influenced the cost-effectiveness of CTC and COL were related to CTC threshold-based reporting of polyps, CTC cost, CTC sensitivity for large polyps, natural history of adenoma transition to cancer, AAA parameters and importantly, adherence. There is a strong need for a differential consideration of patient adherence and compliance to CTC and COL. Recent research shows that laxative-free CTC screening has the potential to become a good alternative screening method for CRC as it can improve patient uptake of screening.

Natural history of colorectal adenomas: birth cohort analysis among 3.6 million participants of screening colonoscopy

BACKGROUND

Most colorectal cancers (CRC) develop from adenomas. Knowledge of the natural history of colorectal adenomas, which is not directly observable for ethical reasons, is crucial for designing cost-effective CRC screening strategies.

METHODS

We derived transition rates from carriage of nonadvanced adenoma to carriage of advanced adenoma to carriage of CRC by sex and age in birth cohort analyses among 3,593,420 participants in the German screening colonoscopy program in 2003-2010.

RESULTS

Transition rates from advanced adenoma to CRC carriage were similar in men and women, but monotonically and significantly increased with age. Estimated annual transition percentages [(95% confidence interval (CI)] in age groups 55-59, 60-64, 65-69, 70-74, and 75-79 years were 2.6 (2.4-2.9), 3.1 (2.8-3.3), 3.8 (3.5-4.1), 5.1 (4.8-5.5), and 5.2 (4.6-5.8) among men, and 2.5 (2.2-2.7), 2.7 (2.4-3.0), 3.8 (3.5-4.1), 5.0 (4.5-5.4), and 5.6 (4.9-6.3) among women. Estimated annual transitions from carriage of nonadvanced to carriage of advanced adenoma were in a narrow range from 3.6% to 4.7% for all age and sex groups.

CONCLUSIONS

Despite low annual transition rates, cumulative transition rates from advanced adenoma to CRC carriage are expected to exceed by 60%, 50%, and 40% for age intervals 55-80, 65-80, and 70-80 years, respectively, in both sexes. Cumulative transition rates from nonadvanced adenoma to CRC carriage are expected to be close to 30% for age interval 55-80 years, but less than 2% for age interval 75-80 years.

IMPACT

Our results enhance the empirical basis for modeling CRC screening strategies.

Cost-effectiveness analysis of 3-D computerized tomography colonography versus optical colonoscopy for imaging symptomatic gastroenterology patients

BACKGROUND

When symptomatic gastroenterology patients have an indication for colonic imaging, clinicians have a choice between optical colonoscopy (OC) and computerized tomography colonography with three-dimensional reconstruction (3-D CTC). 3-D CTC provides a minimally invasive and rapid evaluation of the entire colon, and it can be an efficient modality for diagnosing symptoms. It allows for a more targeted use of OC, which is associated with a higher risk of major adverse events and higher procedural costs. A case can be made for 3-D CTC as a primary test for colonic imaging followed if necessary by targeted therapeutic OC; however, the relative long-term costs and benefits of introducing 3-D CTC as a first-line investigation are unknown.

AIM

The aim of this study was to assess the cost effectiveness of 3-D CTC versus OC for colonic imaging of symptomatic gastroenterology patients in the UK NHS.

METHODS

We used a Markov model to follow a cohort of 100,000 symptomatic gastroenterology patients, aged 50 years or older, and estimate the expected lifetime outcomes, life years (LYs) and quality-adjusted life years (QALYs), and costs (£, 2010-2011) associated with 3-D CTC and OC. Sensitivity analyses were performed to assess the robustness of the base-case cost-effectiveness results to variation in input parameters and methodological assumptions.

RESULTS

3D-CTC provided a similar number of LYs (7.737 vs 7.739) and QALYs (7.013 vs 7.018) per individual compared with OC, and it was associated with substantially lower mean costs per patient (£467 vs £583), leading to a positive incremental net benefit. After accounting for the overall uncertainty, the probability of 3-D CTC being cost effective was around 60 %, at typical willingness-to-pay values of £20,000-£30,000 per QALY gained.

CONCLUSION

3-D CTC is a cost-saving and cost-effective option for colonic imaging of symptomatic gastroenterology patients compared with OC.

Cost-effectiveness of CT colonography

Simulation modeling is extensively applied to CT colonography (CTC) to define its long-term efficacy and cost-effectiveness for colorectal cancer (CRC) screening. CTC is effective in reducing CRC incidence and mortality (40%-77% and 58%-84%, respectively). Several factors may explain this variability. CTC is cost-effective compared with no screening, indicating that it represents an attractive test noncompliance with the available options. CTC needs to achieve a higher attendance rate or cost less than colonoscopy to be cost-effective relative to colonoscopy. Fortunately, both conditions appear to be achievable if CTC becomes a widely utilized and reimbursed screening tool.

Unit costs in population-based colorectal cancer screening using CT colonography performed in university hospitals in The Netherlands

OBJECTIVES

Computed tomography (CT) colonography cost assumptions so far ranged from <euro>346 to <euro>594 per procedure, based on clinical CT reimbursement rates. The aim of our study was to estimate the costs in a screening situation.

METHODS

Data were collected within an invitational population-based CRC screening trial (n = 2,920, age 50-75 years) with a dedicated CT-screening setting. Unit costs were calculated per action, per invitee and per participant (depending on adherence) and per individual with detected advanced neoplasia. Sensitivity analyses were performed, and alternative scenarios were considered.

RESULTS

Of the invitees, 47.2 % were reminded, 38.8 % scheduled for an intake, 37.2 % scheduled for CT colonography, 33.6 % underwent CT colonography and 1.1 % needed a re-examination. Lesions ≥ 10 mm were detected in 2.9 % of the invitees. Invitation costs were Euro 5.57. Costs per CT colonography (intake to results) were Euro 144.00. Extra costs of communication of positive results were Euro 9.00. Average costs of invitational-based CT colonography screening were Euro 56.97 per invitee, Euro 169.40 per participant and Euro 2,772.51 per individual with detected advanced neoplasia.

CONCLUSIONS

Dutch costs of CT-screening were substantially lower than the cost assumptions that were used in published cost-effectiveness analyses on CT colonography screening. This finding indicates that previous cost-effectiveness analyses should be updated, at least for the Dutch situation.

Randomized controlled trial evaluating participation and yield of colonoscopy versus CT colonography screening

Colorectal cancer is a common yet preventable condition. Population screening attempts suffer from a lack of widespread participation with the currently available options. Computerized tomography colonography (CTC) represents a promising addition to the screening armamentarium. CTC is less invasive than optical colonoscopy but has been shown to be equivalent to colonoscopy for the detection of advanced neoplasia, which represents the primary target of screening and prevention. Although CTC has generally been preferred over colonoscopy by patients in most published studies, little hard evidence exists regarding the level of increase in screening participation related to CTC. The landmark trial under discussion adds key data in terms of participation rates for CTC screening relative to colonoscopy screening.

Cost-effectiveness of computed tomography colonography in colorectal cancer screening: a systematic review

OBJECTIVES

The European Code Against Cancer recommends individuals aged ≥ 50 should participate in colorectal cancer screening. CT-colonography (CTC) is one of several screening tests available. We systematically reviewed evidence on, and identified key factors influencing, cost-effectiveness of CTC screening.

METHODS

PubMed, Medline, and the Cochrane library were searched for cost-effectiveness or cost-utility analyses of CTC-based screening, published in English, January 1999 to July 2010. Data was abstracted on setting, model type and horizon, screening scenario(s), comparator(s), participants, uptake, CTC performance and cost, effectiveness, ICERs, and whether extra-colonic findings and medical complications were considered.

RESULTS

Sixteen studies were identified from the United States (n = 11), Canada (n = 2), and France, Italy, and the United Kingdom (1 each). Markov state-transition (n = 14) or microsimulation (n = 2) models were used. Eleven considered direct medical costs only; five included indirect costs. Fourteen compared CTC with no screening; fourteen compared CTC with colonoscopy-based screening; fewer compared CTC with sigmoidoscopy (8) or fecal tests (4). Outcomes assessed were life-years gained/saved (13), QALYs (2), or both (1). Three considered extra-colonic findings; seven considered complications. CTC appeared cost-effective versus no screening and, in general, flexible sigmoidoscopy and fecal occult blood testing. Results were mixed comparing CTC to colonoscopy. Parameters most influencing cost-effectiveness included: CTC costs, screening uptake, threshold for polyp referral, and extra-colonic findings.

CONCLUSION

Evidence on cost-effectiveness of CTC screening is heterogeneous, due largely to between-study differences in comparators and parameter values. Future studies should: compare CTC with currently favored tests, especially fecal immunochemical tests; consider extra-colonic findings; and conduct comprehensive sensitivity analyses.

Comparing the diagnostic yields of technologists and radiologists in an invitational colorectal cancer screening program performed with CT colonography

PURPOSE

To compare the diagnostic yields of a radiologist and trained technologists in the detection of advanced neoplasia within a population-based computed tomographic (CT) colonography screening program.

MATERIALS AND METHODS

Ethical approval was obtained from the Dutch Health Council, and written informed consent was obtained from all participants. Nine hundred eighty-two participants (507 men, 475 women) underwent low-dose CT colonography after noncathartic bowel preparation (iodine tagging) between July 13, 2009, and January 21, 2011. Each scan was evaluated by one of three experienced radiologists (≥800 examinations) by using primary two-dimensional (2D) reading followed by secondary computer-aided detection (CAD) and by two of four trained technologists (≥200 examinations, with colonoscopic verification) by using primary 2D reading followed by three-dimensional analysis and CAD. Immediate colonoscopy was recommended for participants with lesions measuring at least 10 mm, and surveillance was recommended for participants with lesions measuring 6-9 mm. Consensus between technologists was achieved in case of discordant recommendations. Detection of advanced neoplasia (classified by a pathologist) was defined as a true-positive (TP) finding. Relative TP and false-positive (FP) fractions were calculated along with 95% confidence intervals (CIs).

RESULTS

Overall, 96 of the 982 participants were referred for colonoscopy and 104 were scheduled for surveillance. Sixty of 84 participants (71%) referred for colonoscopy by the radiologist had advanced neoplasia, compared with 55 of 64 participants (86%) referred by two technologists. Both the radiologist and technologists detected all colorectal cancers (n = 5). The relative TP fraction (for technologists vs radiologist) for advanced neoplasia was 0.92 (95% CI: 0.78, 1.07), and the relative FP fraction was 0.38 (95% CI: 0.21, 0.67).

CONCLUSION

Two technologists serving as a primary reader of CT colonographic images can achieve a comparable sensitivity to that of a radiologist for the detection of advanced neoplasia, with far fewer FP referrals for colonoscopy.

Incremental net benefit and acceptability of alternative health policies: a case study of mass screening for colorectal cancer

The incremental net benefit (INB) and the related acceptability curves for public health programs provide valuable tools for decision making. We proposed to apply them to the assessment of mass screening of colorectal cancer. The now standard guaiac fecal occult blood test (FOBT) is already implemented in several countries. We considered the innovative immunological FOBT and computed tomography colonography (CTC) as competing screening technologies. Using biennial guaiac FOBT as the reference strategy, we estimated the cost-effectiveness of the following alternatives: biennial immunological FOBT, CTC every 5 years (strategy CTC5), and CTC every 10 years (strategy CTC10). Over a 30-year horizon and from the perspective of a third-party payer, we developed a Markov model on a hypothetical cohort of 100,000 subjects at average risk of colorectal cancer. Close expected net benefits between immunological FOBT and CTC5 induced uncertainty in the choice of the optimal strategy. Probabilistic sensibility analysis then suggested that below a willingness to pay (WTP) per life-years gained (LYG) of 8,587 €/LYG, CTC10 was optimal, while CTC5 would be preferred beyond a WTP of 8,587 €/LYG.

Does CT colonography have a role for population-based colorectal cancer screening?

Colorectal cancer (CRC) is the second most common cancer and second most common cause of cancer-related deaths in Europe. CRC screening has been proven to reduce disease-specific mortality and several European countries employ national screening programmes. These almost exclusively rely on stool tests, with endoscopy used as an adjunct in some countries. Computed tomographic colonography (CTC) is a potential screening test, with an estimated sensitivity of 88 % for advanced neoplasia ≥10 mm. Recent randomised studies have shown that CTC and colonoscopy have similar yields of advanced neoplasia per screened invitee, indicating that CTC is potentially viable as a primary screening test. However, the evidence is not fully elaborated. It is unclear whether CTC screening is cost-effective and the impact of extracolonic findings, both medical and economic, remains unknown. Furthermore, the effect of CTC screening on CRC-related mortality is unknown, as it is also unknown for colonoscopy. It is plausible that both techniques could lead to decreased mortality, as for sigmoidoscopy and gFOBT. Although radiation exposure is a drawback, this disadvantage may be over-emphasised. In conclusion, the detection characteristics and acceptability of CTC suggest it is a viable screening investigation. Implementation will depend on detection of extracolonic disease and health-economic impact. Key Points • Meta-analysis of CT colonographic screening showed high sensitivity for advanced neoplasia ≥10mm. • CTC, colonoscopy and sigmoidoscopy screening all have similar yields for advanced neoplasia. • Good quality information regarding the cost-effectiveness of CTC screening is lacking. • There is little good quality data regarding the impact of extracolonic findings. • CTC triage is not clinically effective in first round gFOBT/FIT positives.

Cost-effectiveness of total colonoscopy in screening of colorectal cancer in Japan

Introduction. In Japan, the cost-effectiveness of total colonoscopy (TCS) for primary screening of colorectal cancer (CRC) is unclear. We compared the cost of identifying a patient with CRC using two primary screening strategies: TCS (strategy 1) and the immunochemical fecal test (FIT) (strategy 2). Materials and Methods. We retrospectively analyzed the TCS screening database at our institution from February 2004 to August 2010 (strategy 1, n = 15,348) and the Japanese nationwide survey of CRC screening in 2008 (strategy 2, n = 5,267,443). Results. 112 and 6,838 CRC cases were detected in strategies 1 and 2, costing 2,124,000 JPY and 1,629,000 JPY, respectively. The rate of earlier-stage CRC was higher in strategy 1. Conclusions. The cost was higher using TCS as a primary screening procedure. However, the difference was not excessive, and considering the increased rate of detecting earlier CRC, the use of TCS as a primary screening tool may be cost-effective.

Physician knowledge and appropriate utilization of computed tomographic colonography in colorectal cancer screening

GOALS

To assess physician understanding of computed tomographic colonography (CTC) in colorectal cancer (CRC) screening guidelines in a pilot study.

BACKGROUND

CTC is a sensitive and specific method of detecting colorectal polyps and cancer. However, several factors have limited its clinical availability, and CRC screening guidelines have issued conflicting recommendations.

STUDY

A web-based survey was administered to physicians at two institutions with and without routine CTC availability.

RESULTS

398 of 1655 (24%) participants completed the survey, 59% was from the institution with routine CTC availability, 52% self-identified as trainees, and 15% as gastroenterologists. 78% had no personal experience with CTC. Only 12% was aware of any current CRC screening guidelines that included CTC. In a multiple regression model, gastroenterologists had greater odds of being aware of guidelines (OR 3.49, CI 1.67-7.26), as did physicians with prior CTC experience (OR 4.81, CI 2.39-9.68), controlling for institution, level of training, sex, and practice type. Based on guidelines that recommend CTC, when given a clinical scenario, 96% of physicians was unable to select the appropriate follow-up after a CTC, which was unaffected by institution.

CONCLUSIONS

Most physicians have limited experience with CTC and are unaware of recent recommendations concerning CTC in CRC screening.

Computer disease simulation models: integrating evidence for health policy

Computer disease simulation models are increasingly being used to evaluate and inform health care decisions across medical disciplines. The aim of researchers who develop these models is to integrate and synthesize short-term outcomes and results from multiple sources to predict the long-term clinical outcomes and costs of different health care strategies. Policy makers, in turn, can use the predictions generated by disease models together with other evidence to make decisions related to health care practices and resource utilization. Models are particularly useful when the existing evidence does not yield obvious answers or does not provide answers to the questions of greatest interest, such as questions about the relative cost-effectiveness of different practices. This review focuses on models used to inform decisions about imaging technology, discussing the role of disease models for health policy development and providing a foundation for understanding the basic principles of disease modeling. This manuscript draws from the collective computed tomographic colonography modeling experience, reviewing 10 published investigations of the clinical effectiveness and cost-effectiveness of computed tomographic colonography relative to colonoscopy. The discussion focuses on implications of different modeling assumptions and difficulties that may be encountered when evaluating the quality of models. This underscores the importance of forging stronger collaborations between researchers who develop disease models and radiologists, to ensure that policy-level models accurately represent the experience of everyday clinical practices.

Comparative economic evaluation of data from the ACRIN National CT Colonography Trial with three cancer intervention and surveillance modeling network microsimulations

PURPOSE

To estimate the cost-effectiveness of computed tomographic (CT) colonography for colorectal cancer (CRC) screening in average-risk asymptomatic subjects in the United States aged 50 years.

MATERIALS AND METHODS

Enrollees in the American College of Radiology Imaging Network National CT Colonography Trial provided informed consent, and approval was obtained from the institutional review board at each site. CT colonography performance estimates from the trial were incorporated into three Cancer Intervention and Surveillance Modeling Network CRC microsimulations. Simulated survival and lifetime costs for screening 50-year-old subjects in the United States with CT colonography every 5 or 10 years were compared with those for guideline-concordant screening with colonoscopy, flexible sigmoidoscopy plus either sensitive unrehydrated fecal occult blood testing (FOBT) or fecal immunochemical testing (FIT), and no screening. Perfect and reduced screening adherence scenarios were considered. Incremental cost-effectiveness and net health benefits were estimated from the U.S. health care sector perspective, assuming a 3% discount rate.

RESULTS

CT colonography at 5- and 10-year screening intervals was more costly and less effective than FOBT plus flexible sigmoidoscopy in all three models in both 100% and 50% adherence scenarios. Colonoscopy also was more costly and less effective than FOBT plus flexible sigmoidoscopy, except in the CRC-SPIN model assuming 100% adherence (incremental cost-effectiveness ratio: $26,300 per life-year gained). CT colonography at 5- and 10-year screening intervals and colonoscopy were net beneficial compared with no screening in all model scenarios. The 5-year screening interval was net beneficial over the 10-year interval except in the MISCAN model when assuming 100% adherence and willingness to pay $50,000 per life-year gained.

CONCLUSION

All three models predict CT colonography to be more costly and less effective than non-CT colonographic screening but net beneficial compared with no screening given model assumptions.

Cost-effectiveness of colorectal cancer screening

Colorectal cancer is an important public health problem. Several screening methods have been shown to be effective in reducing colorectal cancer mortality. The objective of this review was to assess the cost-effectiveness of the different colorectal cancer screening methods and to determine the preferred method from a cost-effectiveness point of view. Five databases (MEDLINE, EMBASE, the Cost-Effectiveness Analysis Registry, the British National Health Service Economic Evaluation Database, and the lists of technology assessments of the Centers for Medicare and Medicaid Services) were searched for cost-effectiveness analyses published in English between January 1993 and December 2009. Fifty-five publications relating to 32 unique cost-effectiveness models were identified. All studies found that colorectal cancer screening was cost-effective or even cost-saving compared with no screening. However, the studies disagreed as to which screening method was most effective or had the best incremental cost-effectiveness ratio for a given willingness to pay per life-year gained. There was agreement among studies that the newly developed screening tests of stool DNA testing, computed tomographic colonography, and capsule endoscopy were not yet cost-effective compared with the established screening options.

Nonmedical costs of colorectal cancer screening using CT colonography

PURPOSE

Nonmedical costs are important because they may influence screening uptake and the results of cost-effectiveness analyses of colorectal cancer (CRC) screening. Although the nonmedical costs of CRC screening are known for fecal occult blood testing, flexible sigmoidoscopy, and colonoscopy, they are unknown for CT colonography (CTC). The purpose of this study was to determine the nonmedical costs of CTC.

METHODS

Four hundred eighty-one consecutive individuals presenting for CRC screening using CTC were approached at a radiology clinic in Calgary, Alberta, Canada, to participate in the study. Of these, 197 agreed to have a questionnaire mailed to them. Subjects completed the questionnaire, including items on time off work, both for the subject and any accompanying caregiver; travel details; and direct out-of-pocket expenses. Time costs were valued at government of Canada wage rates. Travel costs included estimated costs for travel by car and actual parking costs and taxi and public transportation fares. Car user's costs were calculated using a Canadian Automobile Association estimate of motoring costs per kilometer. Costs are reported in 2010 Canadian dollars.

RESULTS

One hundred thirty-two subjects returned the questionnaire (mean age, 57 years; 65% men; 67% employed). Ten subjects traveled >200 km for their CTC. The nonmedical costs (subject with or without caregiver) for the 122 subjects who resided within 200 km of the clinic averaged $101.

CONCLUSIONS

The nonmedical costs of CRC screening using CTC are significant but lower than those of colonoscopy. Patients should be aware of these differential costs, and they should be incorporated into economic analyses of CRC screening.

CT colonography may improve colorectal cancer screening compliance

OBJECTIVE

While colonoscopy is currently the preferred test for colorectal cancer (CRC) screening, the invasive and time-consuming characteristics of the test are often cited as reasons for noncompliance with screening. CT colonography (CTC) is a less invasive screening method that is comparable to colonoscopy for the detection of advanced neoplasia. The aim of this project was to assess patient preferences between colonoscopy and CTC in an open access system.

MATERIALS AND METHODS

Two hundred fifty consecutive average-risk patients undergoing CRC screening completed a survey that assessed reasons for choosing CTC in lieu of colonoscopy, compliance with CRC screening if CTC was not offered, and which of the two tests they preferred.

RESULTS

The most common reasons for undergoing CTC included convenience (33.6%), recommendation by referring provider (13.2%), and perceived safety (10.8%). Had CTC not been an available option, 91 of the 250 patients (36%) would have foregone CRC screening. Among the 57 patients who had experienced both procedures, 95% (n = 54) preferred CTC.

CONCLUSION

These findings show the importance of providing CTC as an alternative screening option for CRC at our institution, which may increase CRC adherence screening rates.

Computed tomographic colonography: ready for prime time?

Computed tomographic (CT) colonography is a noninvasive method to evaluate the colon and has received considerable attention in the last decade as a colon-imaging tool. The technique has also been proposed as a potential primary colon cancer-screening method in the United States. The accuracy of the technique for the detection of large lesions seems to be high, perhaps in the range of colonoscopy. Overall, the field is rapidly evolving. Available data suggest that CT colonography, although a viable colon cancer screening modality in the United States, is not ready for widespread implementation, largely because of the lack of standards for training and reading and the limited number of skilled readers.

Colorectal cancer screening for average-risk North Americans: an economic evaluation

BACKGROUND

Colorectal cancer (CRC) fulfills the World Health Organization criteria for mass screening, but screening uptake is low in most countries. CRC screening is resource intensive, and it is unclear if an optimal strategy exists. The objective of this study was to perform an economic evaluation of CRC screening in average risk North American individuals considering all relevant screening modalities and current CRC treatment costs.

METHODS AND FINDINGS

An incremental cost-utility analysis using a Markov model was performed comparing guaiac-based fecal occult blood test (FOBT) or fecal immunochemical test (FIT) annually, fecal DNA every 3 years, flexible sigmoidoscopy or computed tomographic colonography every 5 years, and colonoscopy every 10 years. All strategies were also compared to a no screening natural history arm. Given that different FIT assays and collection methods have been previously tested, three distinct FIT testing strategies were considered, on the basis of studies that have reported "low," "mid," and "high" test performance characteristics for detecting adenomas and CRC. Adenoma and CRC prevalence rates were based on a recent systematic review whereas screening adherence, test performance, and CRC treatment costs were based on publicly available data. The outcome measures included lifetime costs, number of cancers, cancer-related deaths, quality-adjusted life-years gained, and incremental cost-utility ratios. Sensitivity and scenario analyses were performed. Annual FIT, assuming mid-range testing characteristics, was more effective and less costly compared to all strategies (including no screening) except FIT-high. Among the lifetimes of 100,000 average-risk patients, the number of cancers could be reduced from 4,857 to 1,393 [corrected] and the number of CRC deaths from 1,782 [corrected] to 457, while saving CAN$68 per person. Although screening patients with FIT became more expensive than a strategy of no screening when the test performance of FIT was reduced, or the cost of managing CRC was lowered (e.g., for jurisdictions that do not fund expensive biologic chemotherapeutic regimens), CRC screening with FIT remained economically attractive.

CONCLUSIONS

CRC screening with FIT reduces the risk of CRC and CRC-related deaths, and lowers health care costs in comparison to no screening and to other existing screening strategies. Health policy decision makers should consider prioritizing funding for CRC screening using FIT.

Cost-effectiveness of colorectal cancer screening with computed tomography colonography or fecal blood tests

OBJECTIVE

To assess the cost-effectiveness of colorectal cancer screening using computed tomography colonography (CTC) and immunological fecal occult blood test (iFOBT).

METHODS

CTC and iFOBT strategies were compared with Nn screening or guaiac FOBT (gFOBT) using Markov modeling. CTC was proposed at 50, 60, and 70 years, whereas gFOBT and iFOBT were performed every 2 years beginning at 50 years until 74 years of age with a 30-year time horizon. We calculated incremental cost-effectiveness ratios and efficiency ratios (ERs). Then, we performed univariate and probabilistic sensitivity analyses.

RESULTS

With gFOBT as reference, colorectal cancer prevention rate was 18% for CTC and 11% for iFOBT. The incremental cost-effectiveness ratio of CTC and iFOBT were respectively 3204 and 5458 euro per life years gained (LYG), the ER for CTC was 0.22 and the ER for iFOBT was 2.08 colonoscopies per LYG. Cost-effectiveness results were sensitive to CTC cost. In the probabilistic sensitivity analysis, compared with CTC, iFOBT strategy was cost-effective for 84.6% of simulations when we assumed a willingness to pay (WTP) of 20,000 euro/LYG.

CONCLUSION

CTC requires substantially less colonoscopies than iFOBT and is cost-effective for low values of WTP. However, iFOBT is the preferred screening strategy for a WTP greater than 6207 euro/LYG.

Colorectal cancer screening: The role of CT colonography

Computed tomography colonography (CTC) in colorectal cancer (CRC) screening has two roles: one present and the other potential. The present role is, without any further discussion, the integration into established screening programs as a replacement for barium enema in the case of incomplete colonoscopy. The potential role is the use of CTC as a first-line screening method together with Fecal Occult Blood Test, sigmoidoscopy and colonoscopy. However, despite the fact that CTC has been officially endorsed for CRC screening of average-risk individuals by different scientific societies including the American Cancer Society, the American College of Radiology, and the US Multisociety Task Force on Colorectal Cancer, other entities, such as the US Preventive Services Task Force, have considered the evidence insufficient to justify its use as a mass screening method. Medicare has also recently denied reimbursement for CTC as a screening test. Nevertheless, multiple advantages exist for using CTC as a CRC screening test: high accuracy, full evaluation of the colon in virtually all patients, non-invasiveness, safety, patient comfort, detection of extracolonic findings and cost-effectiveness. The main potential drawback of a CTC screening is the exposure to ionizing radiation. However, this is not a major issue, since low-dose protocols are now routinely implemented, delivering a dose comparable or slightly superior to the annual radiation exposure of any individual. Indirect evidence exists that such a radiation exposure does not induce additional cancers.

Quality and safety of screening colonoscopies performed by primary care physicians with standby specialist support

BACKGROUND

Expanding the population's access to colonoscopy screening can reduce colorectal cancer disparities. Innovative strategies are needed to address the prevailing 50% colonoscopy screening gap, partly attributable to inadequate specialist workforce. This study examined the quality of colonoscopies by primary care physicians (PCPs) with standby specialist support at a licensed ambulatory surgery center.

METHODS

Retrospective data on 10,958 consecutive colonoscopies performed by 51 PCPs on 9815 patients from October 2002 to November 2007 were used to calculate the rates of cecal intubation, detection of polyps, adenomas, advanced neoplasia and cancer, adverse events, and time taken for endoscope insertion and withdrawal. The center's protocol requires a 2-person technique (using a trained technician), polyp search and removal during both scope insertion and withdrawal, and onsite expert always available for rescue assistance (either navigational or therapeutic).

FINDINGS

Mean patient age was 58.3 (+/-10.9) years, 48.0% were male, and 48.1% African-American. The cecal intubation rate was 98.1%, polyp detection rate 63.1%, hyperplastic polyp 27.5%, adenoma 29.9%, advanced neoplasia 5.7%, cancer 0.63%, major adverse events 0.06% (including 2 perforations; no death). Mean insertion and withdrawal times were 14.4 (+/-9.3) and 10.9 (+/-6.8) minutes, respectively; 13.2 (+/-8.6) and 8.0 (+/-4.5) minutes without polyps found, and 15.1 (+/-9.6) and 12.5 (+/-7.3) minutes when > or =1 polyp was found.

CONCLUSIONS

In the largest published study of PCP-performed colonoscopies with standby specialist support, we observed performance quality indicators and lesion detection rates that are comparable to documented rates for experienced gastroenterologists. Systems that use PCPs with specialist backup support enable high-quality colonoscopy performance by PCPs.

Cost-effectiveness of colorectal cancer screening - an overview

There are several modalities available for a colorectal cancer (CRC) screening program. When determining which CRC screening program to implement, the costs of such programs should be considered in comparison to the health benefits they are expected to provide. Cost-effectiveness analysis provides a tool to do this. In this paper we review the evidence on the cost-effectiveness of CRC screening. Published studies universally indicate that when compared with no CRC screening, all screening modalities provide additional years of life at a cost that is deemed acceptable by most industrialized nations. Many recent studies even find CRC screening to be cost-saving. However, when the alternative CRC screening strategies are compared against each other in an incremental cost-effectiveness analysis, no single optimal strategy emerges across the studies. There is consensus that the new technologies of stool DNA testing, computed tomographic colonography and capsule endoscopy are not yet cost-effective compared with the established CRC screening tests.

When budgets are tight, there are better options than colonoscopies for colorectal cancer screening

A critical challenge facing cancer screening programs, particularly those aimed at uninsured people with low incomes, is choosing the screening test that makes the most efficient use of limited budgets. For colorectal cancer screening, there is growing momentum to use colonoscopy, which is an expensive test. In this study, we modeled scenarios to assess whether the use of fecal occult blood tests or colonoscopy provides the most benefit under conditions of budget constraints. We found that although colonoscopy is more accurate, under most scenarios, fecal occult blood tests would result in more individuals' getting screened, with more life-years gained.

Cost-effectiveness of computed tomographic colonography screening for colorectal cancer in the medicare population

BACKGROUND

The Centers for Medicare and Medicaid Services (CMS) considered whether to reimburse computed tomographic colonography (CTC) for colorectal cancer screening of Medicare enrollees. To help inform its decision, we evaluated the reimbursement rate at which CTC screening could be cost-effective compared with the colorectal cancer screening tests that are currently reimbursed by CMS and are included in most colorectal cancer screening guidelines, namely annual fecal occult blood test (FOBT), flexible sigmoidoscopy every 5 years, flexible sigmoidoscopy every 5 years in conjunction with annual FOBT, and colonoscopy every 10 years.

METHODS

We used three independently developed microsimulation models to assess the health outcomes and costs associated with CTC screening and with currently reimbursed colorectal cancer screening tests among the average-risk Medicare population. We assumed that CTC was performed every 5 years (using test characteristics from either a Department of Defense CTC study or the National CTC Trial) and that individuals with findings of 6 mm or larger were referred to colonoscopy. We computed incremental cost-effectiveness ratios for the currently reimbursed screening tests and calculated the maximum cost per scan (ie, the threshold cost) for the CTC strategy to lie on the efficient frontier. Sensitivity analyses were performed on key parameters and assumptions.

RESULTS

Assuming perfect adherence with all tests, the undiscounted number life-years gained from CTC screening ranged from 143 to 178 per 1000 65-year-olds, which was slightly less than the number of life-years gained from 10-yearly colonoscopy (152-185 per 1000 65-year-olds) and comparable to that from 5-yearly sigmoidoscopy with annual FOBT (149-177 per 1000 65-year-olds). If CTC screening was reimbursed at $488 per scan (slightly less than the reimbursement for a colonoscopy without polypectomy), it would be the most costly strategy. CTC screening could be cost-effective at $108-$205 per scan, depending on the microsimulation model used. Sensitivity analyses showed that if relative adherence to CTC screening was 25% higher than adherence to other tests, it could be cost-effective if reimbursed at $488 per scan.

CONCLUSIONS

CTC could be a cost-effective option for colorectal cancer screening among Medicare enrollees if the reimbursement rate per scan is substantially less than that for colonoscopy or if a large proportion of otherwise unscreened persons were to undergo screening by CTC.

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.

Polyp surveillance

Surveillance after colonic polypectomy is important to detect and remove missed synchronous polyps and cancers and new metachronous polyps or cancers. The authors review methods of surveillance and the risk of recurrent adenomas and provide surveillance recommendations.