The impact on clinical outcomes and healthcare resources from discontinuing colonoscopy surveillance subsequent to low-risk adenoma removal: A simulation study using the OncoSim-Colorectal model

OBJECTIVE

To estimate the impact on clinical outcomes and healthcare resource use from recommending that patients with 1-2 low-risk adenomas (LRAs) return to routine fecal immunochemical test (FIT) screening instead of surveillance colonoscopy, from a Canadian provincial healthcare system perspective.

METHODS

The OncoSim-Colorectal microsimulation model simulated average-risk individuals eligible for FIT-based colorectal cancer (CRC) screening in Alberta, Canada. We simulated two surveillance strategies that applied to individuals with 1-2 LRAs (<10 mm) removed as part of the average risk CRC screening program: (a) Surveillance colonoscopy (status quo) and (b) return to FIT screening (new strategy); both at 5 years after polypectomy. A 75 ng/mL FIT positivity threshold was used in the base case. The simulations projected average annual CRC outcomes and healthcare resource use from 2023 to 2042. We conducted alternative scenarios and sensitivity analyses on key variables.

RESULTS

Returning to FIT screening (versus surveillance colonoscopy) after polypectomy was projected to have minimal impact on long-term CRC incidence and deaths (not statistically significant). There was a projected decrease of one (4%) major bleeding event and seven (5%) perforation events per year. There was a projected increase of 4800 (1.5%) FIT screens, decrease of 3900 (5.1%) colonoscopies, and a decrease of $3.4 million (1.2%) in total healthcare costs per year, on average. The annual colonoscopies averted and healthcare cost savings increased over time. Results were similar in the alternative scenarios and sensitivity analyses.

CONCLUSIONS

Returning to FIT screening would have similar clinical outcomes as surveillance colonoscopy but could reduce colonoscopy demand and healthcare costs.

The projected health and economic impact of increased colorectal cancer screening participation among Canadians by income quintile

OBJECTIVES

Disparities in colorectal cancer (CRC) screening uptake by socioeconomic status have been observed in Canada. We used the OncoSim-Colorectal model to evaluate the health and economic outcomes associated with increasing the participation rates of CRC screening programs to 60% among Canadians in different income quintiles.

METHODS

Baseline CRC screening participation rates were obtained from the 2017 Canadian Community Health Survey. The survey participants were categorized into income quintiles using their reported household income and 2016 Canadian Census income quintile thresholds. Within each quintile, the participation rate was the proportion of respondents aged 50-74 who reported having had a fecal test in the past two years. Using the OncoSim-Colorectal model, we simulated an increase in CRC screening uptake to 60% across income quintiles to assess the effects on CRC incidence, mortality, and associated economic costs from 2024 to 2073.

RESULTS

Increasing CRC screening participation rates to 60% across all income quintiles would prevent 69,100 CRC cases and 36,600 CRC deaths over 50 years. The improvement of clinical outcomes would also translate to increased person-years and health-adjusted person-years. The largest impact was observed in the lowest income group, with 22,200 cases and 11,700 deaths prevented over 50 years. Increased participation could lead to higher screening costs ($121 million CAD more per year) and lower treatments costs ($95 million CAD less per year), averaged over the period 2024-2073.

CONCLUSION

Increased screening participation will improve clinical outcomes across all income groups while alleviating associated treatment costs. The benefits of increased participation will be strongest among the lowest income quintile.

The OncoSim-Breast Cancer Microsimulation Model

Background: OncoSim-Breast is a Canadian breast cancer simulation model to evaluate breast cancer interventions. This paper aims to describe the OncoSim-Breast model and how well it reproduces observed breast cancer trends. Methods: The OncoSim-Breast model simulates the onset, growth, and spread of invasive and ductal carcinoma in situ tumours. It combines Canadian cancer incidence, mortality, screening program, and cost data to project population-level outcomes. Users can change the model input to answer specific questions. Here, we compared its projections with observed data. First, we compared the model’s projected breast cancer trends with the observed data in the Canadian Cancer Registry and from Vital Statistics. Next, we replicated a screening trial to compare the model’s projections with the trial’s observed screening effects. Results: OncoSim-Breast’s projected incidence, mortality, and stage distribution of breast cancer were close to the observed data in the Canadian Cancer Registry and from Vital Statistics. OncoSim-Breast also reproduced the breast cancer screening effects observed in the UK Age trial. Conclusions: OncoSim-Breast’s ability to reproduce the observed population-level breast cancer trends and the screening effects in a randomized trial increases the confidence of using its results to inform policy decisions related to early detection of breast cancer.

Predicted long-term impact of COVID-19 pandemic-related care delays on cancer mortality in Canada

The COVID‐19 pandemic has affected cancer care worldwide. This study aimed to estimate the long‐term impacts of cancer care disruptions on cancer mortality in Canada using a microsimulation model. The model simulates cancer incidence and survival using cancer incidence, stage at diagnosis and survival data from the Canadian Cancer Registry. We modeled reported declines in cancer diagnoses and treatments recorded in provincial administrative datasets in March 2020 to June 2021. Based on the literature, we assumed that diagnostic and treatment delays lead to a 6% higher rate of cancer death per 4‐week delay. After June 2021, we assessed scenarios where cancer treatment capacity returned to prepandemic levels, or to 10% higher or lower than prepandemic levels. Results are the median predictions of 10 stochastic simulations. The model predicts that cancer care disruptions during the COVID‐19 pandemic could lead to 21 247 (2.0%) more cancer deaths in Canada in 2020 to 2030, assuming treatment capacity is recovered to 2019 prepandemic levels in 2021. This represents 355 172 life years lost expected due to pandemic‐related diagnostic and treatment delays. The largest number of expected excess cancer deaths was predicted for breast, lung and colorectal cancers, and in the provinces of Ontario, Québec and British Columbia. Diagnostic and treatment capacity in 2021 onward highly influenced the number of cancer deaths over the next decade. Cancer care disruptions during the COVID‐19 pandemic could lead to significant life loss; however, most of these could be mitigated by increasing diagnostic and treatment capacity in the short‐term to address the service backlog.

Impact of the COVID-19 pandemic on faecal immunochemical test-based colorectal cancer screening programmes in Australia, Canada, and the Netherlands: a comparative modelling study

BACKGROUND

Colorectal cancer screening programmes worldwide have been disrupted during the COVID-19 pandemic. We aimed to estimate the impact of hypothetical disruptions to organised faecal immunochemical test-based colorectal cancer screening programmes on short-term and long-term colorectal cancer incidence and mortality in three countries using microsimulation modelling.

METHODS

In this modelling study, we used four country-specific colorectal cancer microsimulation models-Policy1-Bowel (Australia), OncoSim (Canada), and ASCCA and MISCAN-Colon (the Netherlands)-to estimate the potential impact of COVID-19-related disruptions to screening on colorectal cancer incidence and mortality in Australia, Canada, and the Netherlands annually for the period 2020-24 and cumulatively for the period 2020-50. Modelled scenarios varied by duration of disruption (3, 6, and 12 months), decreases in screening participation after the period of disruption (0%, 25%, or 50% reduction), and catch-up screening strategies (within 6 months after the disruption period or all screening delayed by 6 months).

FINDINGS

Without catch-up screening, our analysis predicted that colorectal cancer deaths among individuals aged 50 years and older, a 3-month disruption would result in 414-902 additional new colorectal cancer diagnoses (relative increase 0·1-0·2%) and 324-440 additional deaths (relative increase 0·2-0·3%) in the Netherlands, 1672 additional diagnoses (relative increase 0·3%) and 979 additional deaths (relative increase 0·5%) in Australia, and 1671 additional diagnoses (relative increase 0·2%) and 799 additional deaths (relative increase 0·3%) in Canada between 2020 and 2050, compared with undisrupted screening. A 6-month disruption would result in 803-1803 additional diagnoses (relative increase 0·2-0·4%) and 678-881 additional deaths (relative increase 0·4-0·6%) in the Netherlands, 3552 additional diagnoses (relative increase 0·6%) and 1961 additional deaths (relative increase 1·0%) in Australia, and 2844 additional diagnoses (relative increase 0·3%) and 1319 additional deaths (relative increase 0·4%) in Canada between 2020 and 2050, compared with undisrupted screening. A 12-month disruption would result in 1619-3615 additional diagnoses (relative increase 0·4-0·9%) and 1360-1762 additional deaths (relative increase 0·8-1·2%) in the Netherlands, 7140 additional diagnoses (relative increase 1·2%) and 3968 additional deaths (relative increase 2·0%) in Australia, and 5212 additional diagnoses (relative increase 0·6%) and 2366 additional deaths (relative increase 0·8%) in Canada between 2020 and 2050, compared with undisrupted screening. Providing immediate catch-up screening could minimise the impact of the disruption, restricting the relative increase in colorectal cancer incidence and deaths between 2020 and 2050 to less than 0·1% in all countries. A post-disruption decrease in participation could increase colorectal cancer incidence by 0·2-0·9% and deaths by 0·6-1·6% between 2020 and 2050, compared with undisrupted screening.

INTERPRETATION

Although the projected effect of short-term disruption to colorectal cancer screening is modest, such disruption will have a marked impact on colorectal cancer incidence and deaths between 2020 and 2050 attributable to missed screening. Thus, it is crucial that, if disrupted, screening programmes ensure participation rates return to previously observed rates and provide catch-up screening wherever possible, since this could mitigate the impact on colorectal cancer deaths.

FUNDING

Cancer Council New South Wales, Health Canada, and Dutch National Institute for Public Health and Environment.

Association between air travel and importation of chikungunya into the USA

Background: During infectious disease outbreaks with pandemic potential, the number of air passengers travelling from the outbreak source to international destinations has been used as a proxy for disease importation risk to new locations. However, evaluations of the validity of this approach are limited. We sought to quantify the association between international air travel and disease importation using the 2014-2016 chikungunya outbreak in the Americas as a case study. Methods: We used country-level chikungunya case data to define a time period of epidemic activity for each of the 45 countries and territories in the Americas reporting outbreaks between 2014 and 2016. For each country, we identified airports within or proximate to areas considered suitable for chikungunya transmission and summed the number of commercial air passengers departing from these airports during the epidemic period to each US state. We used negative binomial models to quantify the association between the number of incoming air passengers from countries experiencing chikungunya epidemics and the annual rate of chikungunya importation into the USA at the state level. Results: We found a statistically significant positive association between passenger flows via airline travel from countries experiencing chikungunya epidemics and the number of imported cases in the USA at the state level (P < 0.0001). Additionally, we found that as the number of arriving airline passengers increased by 10%, the estimated number of imported cases increased by 5.2% (95% CI: 3.0-7.6). Conclusion: This validation study demonstrated that air travel was strongly associated with observed importation of chikungunya cases in the USA and can be a useful proxy for identifying areas at increased risk for disease importation. This approach may be useful for understanding exportation risk of other arboviruses.

Infectious disease implications of large-scale migration of Venezuelan nationals

Background

The ongoing economic and political crisis in Venezuela has resulted in a collapse of the healthcare system and the re-emergence of previously controlled or eliminated infectious diseases. There has also been an exodus of Venezuelan international migrants in response to the crisis. We sought to describe the infectious disease risks faced by Venezuelan nationals and assess the international mobility patterns of the migrant population.

Methods

We synthesized data on recent infectious disease events in Venezuela and among international migrants from Venezuela, as well as on current country of residence among the migrant population. We used passenger-level itinerary data from the International Air Transport Association to evaluate trends in outbound air travel from Venezuela over time. We used two parameter-free mobility models, the radiation and impedance models, to estimate the expected population flows from Venezuelan cities to other major Latin American and Caribbean cities.

Results

Outbreaks of measles, diphtheria and malaria have been reported across Venezuela and other diseases, such as HIV and tuberculosis, are resurgent. Changes in migration in response to the crisis are apparent, with an increase in Venezuelan nationals living abroad, despite an overall decline in the number of outbound air passengers. The two models predicted different mobility patterns, but both highlighted the importance of Colombian cities as destinations for migrants and also showed that some migrants are expected to travel large distances. Despite the large distances that migrants may travel internationally, outbreaks associated with Venezuelan migrants have occurred primarily in countries proximate to Venezuela.

Conclusions

Understanding where international migrants are relocating is critical, given the association between human mobility and the spread of infectious diseases. In data-limited situations, simple models can be useful for providing insights into population mobility and may help identify areas likely to receive a large number of migrants.

Harms, benefits and costs of fecal immunochemical testing versus guaiac fecal occult blood testing for colorectal cancer screening

BACKGROUND

The ColonCancerCheck screening program for colorectal cancer (CRC) in Ontario, Canada, is considering switching from biennial guaiac fecal occult blood test (gFOBT) screening between age 50-74 years to the more sensitive, but also less specific fecal immunochemical test (FIT). The aim of this study is to estimate whether the additional benefits of FIT screening compared to gFOBT outweigh the additional costs and harms.

METHODS

We used microsimulation modeling to estimate quality adjusted life years (QALYs) gained and costs of gFOBT and FIT, compared to no screening, in a cohort of screening participants. We compared strategies with various age ranges, screening intervals, and cut-off levels for FIT. Cost-efficient strategies were determined for various levels of available colonoscopy capacity.

RESULTS

Compared to no screening, biennial gFOBT screening between age 50-74 years provided 20 QALYs at a cost of CAN$200,900 per 1,000 participants, and required 17 colonoscopies per 1,000 participants per year. FIT screening was more effective and less costly. For the same level of colonoscopy requirement, biennial FIT (with a high cut-off level of 200 ng Hb/ml) between age 50-74 years provided 11 extra QALYs gained while saving CAN$333,300 per 1000 participants, compared to gFOBT. Without restrictions in colonoscopy capacity, FIT (with a low cut-off level of 50 ng Hb/ml) every year between age 45-80 years was the most cost-effective strategy providing 27 extra QALYs gained per 1000 participants, while saving CAN$448,300.

INTERPRETATION

Compared to gFOBT screening, switching to FIT at a high cut-off level could increase the health benefits of a CRC screening program without considerably increasing colonoscopy demand.

Estimating the costs of intensity-modulated and 3-dimensional conformal radiotherapy in Ontario

BACKGROUND

Radiotherapy is a common treatment for many cancers, but up-to-date estimates of the costs of radiotherapy are lacking. In the present study, we estimated the unit costs of intensity-modulated radiotherapy (imrt) and 3-dimensional conformal radiotherapy (3D-crt) in Ontario.

METHODS

An activity-based costing model was developed to estimate the costs of imrt and 3D-crt in prostate cancer. It included the costs of equipment, staff, and supporting infrastructure. The framework was subsequently adapted to estimate the costs of radiotherapy in breast cancer and head-and-neck cancer. We also tested various scenarios by varying the program maturity and the use of volumetric modulated arc therapy (vmat) alongside imrt.

RESULTS

From the perspective of the health care system, treating prostate cancer with imrt and 3D-crt respectively cost $12,834 and $12,453 per patient. The cost of radiotherapy ranged from $5,270 to $14,155 and was sensitive to analytic perspective, radiation technique, and disease site. Cases of head-and-neck cancer were the most costly, being driven by treatment complexity and fractions per treatment. Although imrt was more costly than 3D-crt, its cost will likely decline over time as programs mature and vmat is incorporated.

CONCLUSIONS

Our costing model can be modified to estimate the costs of 3D-crt and imrt for various disease sites and settings. The results demonstrate the important role of capital costs in studies of radiotherapy cost from a health system perspective, which our model can accommodate. In addition, our study established the need for future analyses of imrt cost to consider how vmat affects time consumption.

Omission of Breast Radiotherapy in Low-risk Luminal A Breast Cancer: Impact on Health Care Costs

AIMS

The economic burden of cancer care is substantial, including steep increases in costs for breast cancer management. There is mounting evidence that women age ≥ 60 years with grade I/II T1N0 luminal A (ER/PR+, HER2- and Ki67 ≤ 13%) breast cancer have such low local recurrence rates that adjuvant breast radiotherapy might offer limited value. We aimed to determine the total savings to a publicly funded health care system should omission of radiotherapy become standard of care for these patients.

MATERIALS AND METHODS

The number of women aged ≥ 60 years who received adjuvant radiotherapy for T1N0 ER+ HER2- breast cancer in Ontario was obtained from the provincial cancer agency. The cost of adjuvant breast radiotherapy was estimated through activity-based costing from a public payer perspective. The total saving was calculated by multiplying the estimated number of luminal A cases that received radiotherapy by the cost of radiotherapy minus Ki-67 testing.

RESULTS

In 2010, 748 women age ≥ 60 years underwent surgery for pT1N0 ER+ HER2- breast cancer; 539 (72%) underwent adjuvant radiotherapy, of whom 329 were estimated to be grade I/II luminal A subtype. The cost of adjuvant breast radiotherapy per case was estimated at $6135.85; the cost of Ki-67 at $114.71. This translated into an annual saving of about $2.0million if radiotherapy was omitted for all low-risk luminal A breast cancer patients in Ontario and $5.1million across Canada.

CONCLUSION

There will be significant savings to the health care system should omission of radiotherapy become standard practice for women with low-risk luminal A breast cancer.

Cost-effectiveness of a fracture liaison service--a real-world evaluation after 6 years of service provision

The cost-effectiveness of a less intensive fracture liaison service is unknown. We evaluated a fracture liaison service that had been educating and referring patients for secondary prevention of osteoporotic fractures for 6 years. Our results suggest that a less intensive fracture liaison service, with moderate effectiveness, can still be worthwhile.

INTRODUCTION

Fragility fractures are common among older patients; the risk of re-fracture is high but could be reduced with treatments; different versions of fracture liaison service have emerged to reduce recurrent osteoporotic fractures. But the cost-effectiveness of a less intensive model is unknown. The objective of this study was to assess the cost-effectiveness of the Ontario Fracture Clinic Screening program, a fracture liaison service that had been educating and referring fragility fracture patients across Ontario, Canada to receive bone mineral density testing and osteoporosis treatments since 2007.

METHODS

We developed a Markov model to assess the cost-effectiveness of the program over the patients' remaining lifetime, using rates of bone mineral density testing and osteoporosis treatment and cost of intervention from the program, and supplemented it with the published literature. The analysis took the perspective of a third-party health-care payer. Costs and benefits were discounted at 5 % per year. Sensitivity analyses assessed the effects of different assumptions on the results.

RESULTS

The program improved quality-adjusted life-years (QALYs) by 4.3 years and led to increased costs of CAD $83,000 for every 1000 patients screened, at a cost of $19,132 per QALY gained. The enhanced model, the Bone Mineral Density (BMD) Fast Track program that includes ordering bone mineral density testing, was even more cost-effective ($5720 per QALY gained).

CONCLUSIONS

The Ontario Fracture Clinic Screening program appears to be a cost-effective way to reduce recurrent osteoporotic fractures.

The impact of stratifying by family history in colorectal cancer screening programs

In the province-wide colorectal cancer (CRC) screening program in Ontario, Canada, individuals with a family history of CRC are offered colonoscopy screening and those without are offered guaiac fecal occult blood testing (gFOBT, Hemoccult II). We used microsimulation modeling to estimate the cumulative number of CRC deaths prevented and colonoscopies performed between 2008 and 2038 with this family history-based screening program, compared to a regular gFOBT program. In both programs, we assumed screening uptake increased from 30% (participation level in 2008 before the program was launched) to 60%. We assumed that 11% of the population had a family history, defined as having at least one first-degree relative diagnosed with CRC. The programs offered screening between age 50 and 74 years, every two years for gFOBT, and every ten years for colonoscopy. Compared to opportunistic screening (2008 participation level kept constant at 30%), the gFOBT program cumulatively prevented 6,700 more CRC deaths and required 570,000 additional colonoscopies by 2038. The family history-based screening program increased these numbers to 9,300 and 1,100,000, a 40% and 93% increase, respectively. If biennial gFOBT was replaced with biennial fecal immunochemical test (FIT), annual Hemoccult Sensa or five-yearly sigmoidoscopy screening, both the added benefits and colonoscopies required would decrease. A biennial gFOBT screening program that identifies individuals with a family history of CRC and recommends them to undergo colonoscopy screening would prevent 40% (range in sensitivity analyses: 20-51%) additional deaths while requiring 93% (range: 43-116%) additional colonoscopies, compared to a regular gFOBT screening program.

The evaluation and use of economic evidence to inform cancer drug reimbursement decisions in Canada

BACKGROUND

Cost-effectiveness evidence is increasingly considered in the reimbursement decisions of pharmaceuticals. In some jurisdictions such as the UK and Canada, pharmaceutical manufacturers are required to submit economic evaluations when seeking reimbursement.

OBJECTIVES

Our objectives were to describe the role of economic evidence in the cancer drug review process in Canada, and to investigate the nature of problems encountered in the review and interpretation of economic evidence used in the process.

DESIGN

We conducted a retrospective review of cancer drug review meeting minutes and reviewers' comments on pharmacoeconomic studies submitted to the oncology drug review process in Canada.

DATA SOURCES

We used pharmacoeconomic reviewers' reports and relevant cancer drug review expert advisory committee meeting minutes during the first year of the review process (April 2007 to March 2008).

RESULTS

Fifteen economic submissions were reviewed. One-third of the studies had flaws significant enough that the advisory committee could not determine the cost effectiveness of the drugs from the results. The common issues outlined by the reviewers and committee were related to the uncertainty of comparative clinical benefits, quality of life and costs. The reviewers felt that few analyses provided sufficient sensitivity analyses around key variables to assess the robustness of results. Most problems identified by reviewers are simple to fix and do not involve advanced methods.

CONCLUSIONS

Canada has a separate review process for making cancer drug funding recommendations, and this process uses both clinical and economic evidence. The committee could not determine the value for money of the drugs from several of the submitted pharmacoeconomic analyses. Transparent analyses and detailed critique of evidence are crucial to the use of economic evidence in reimbursement decisions. Rigorous evaluation is resource intensive and may benefit from a shared drug review process among several jurisdictions.

Cost-effectiveness of intensity-modulated radiotherapy in prostate cancer

AIMS

To compare the costs and effectiveness of intensity-modulated radiotherapy (IMRT) with three-dimensional conformal radiotherapy (3DCRT) for the radical treatment of localised prostate cancer at elevated doses (>70 Gy).

MATERIALS AND METHODS

A cost-effectiveness analysis model was developed using clinical effectiveness estimates from a systematic review. The base case analysis assumes equal biochemical survival for IMRT and 3DCRT, but lower frequency of gastrointestinal toxicity for IMRT. The costs of IMRT and 3DCRT were estimated through activity-based costing, incorporating input from radiation oncologists, physicists and treatment planners.

RESULTS

The delivery of IMRT produced 0.023 more quality-adjusted life-years (QALY) than 3DCRT at an additional cost of $621 (QALY and costs discounted at 5% per year), yielding an incremental cost-effectiveness ratio of $26 768 per QALY gained. The treatment cost of IMRT was $1019 more than 3DCRT, but IMRT resulted in less frequent gastrointestinal toxicity, thus avoiding $402 in the treatment of toxicity. In the scenario that compared a higher dose of IMRT (75.6 Gy) to 3DCRT (68.4 Gy), IMRT improved disease control with equal toxicity incidence, and the IMRT strategy dominated (less costly and more effective). In the base case scenario (no survival difference), the cost-effectiveness of IMRT was most sensitive to the treatment cost difference between IMRT and 3DCRT.

CONCLUSION

For radical radiation treatment (>70 Gy) of prostate cancer, IMRT seems to be cost-effective when compared with an equivalent dose of 3DCRT.