Discussions with patients about referral pathways and costs in the diagnosis and treatment of colorectal cancer in Victoria, Australia.

BACKGROUND AND OBJECTIVES: Colorectal cancer (CRC) survival in Australia differs by health insurance status, but why this occurs is uncertain. There are growing concerns about out-of-pocket healthcare costs. We examined patient experiences of referral pathways to diagnosis and treatment of CRC in Victoria, Australia, and discussions about costs, comparing public, private and mixed healthcare system users. METHOD: Semistructured telephone interviews were conducted with 16 purposively sampled, English-speaking patients aged ≥40 years with CRC. Interviews were recorded, transcribed and analysed thematically. RESULTS: Private patients described greater out-of-pocket expenses balanced by greater choice of provider and access. Public patients perceived limited choice in their diagnostic or treatment provider, although some considered switching systems. Patients trusted their general practitioner or specialist for referrals. Discussions about costs did not meet guideline recommendations. DISCUSSION: There are limited opportunities for informed decision making about public versus private care for cancer diagnosis and treatment, which could contribute to inequalities in outcomes.

Proactive breast cancer risk assessment in primary care: a review based on the principles of screening.

In the UK, the National Institute for Health and Care Excellence (NICE) recommends that women at moderate or high risk of breast cancer be offered risk-reducing medication and enhanced breast screening/surveillance. In June 2022, NICE withdrew a statement recommending assessment of risk in primary care only when women present with concerns. This shift to the proactive assessment of risk substantially changes the role of primary care, in effect paving the way for a primary care-based screening programme to identify those at moderate or high risk of breast cancer. In this article, we review the literature surrounding proactive breast cancer risk assessment within primary care against the consolidated framework for screening. We find that risk assessment for women under 50 years currently satisfies many of the standard principles for screening. Most notably, there are large numbers of women at moderate or high risk currently unidentified, risk models exist that can identify those women with reasonable accuracy, and management options offer the opportunity to reduce breast cancer incidence and mortality in that group. However, there remain a number of uncertainties and research gaps, particularly around the programme/system requirements, that need to be addressed before these benefits can be realised.

The Australian Reproductive Genetic Carrier Screening Project (Mackenzie's Mission): Design and Implementation.

Reproductive genetic carrier screening (RGCS) provides people with information about their chance of having children with autosomal recessive or X-linked genetic conditions, enabling informed reproductive decision-making. RGCS is recommended to be offered to all couples during preconception or in early pregnancy. However, cost and a lack of awareness may prevent access. To address this, the Australian Government funded Mackenzie's Mission­the Australian Reproductive Genetic Carrier Screening Project. Mackenzie's Mission aims to assess the acceptability and feasibility of an easily accessible RGCS program, provided free of charge to the participant. In study Phase 1, implementation needs were mapped, and key study elements were developed. In Phase 2, RGCS is being offered by healthcare providers educated by the study team. Reproductive couples who provide consent are screened for over 1200 genes associated with >750 serious, childhood-onset genetic conditions. Those with an increased chance result are provided comprehensive genetic counseling support. Reproductive couples, recruiting healthcare providers, and study team members are also invited to complete surveys and/or interviews. In Phase 3, a mixed-methods analysis will be undertaken to assess the program outcomes, psychosocial implications and implementation considerations alongside an ongoing bioethical analysis and a health economic evaluation. Findings will inform the implementation of an ethically robust RGCS program.

Exploring the role of general practitioners in addressing financial toxicity in cancer patients.

PURPOSE: Financial toxicity (FT) describes financial distress or hardship as an outcome of cancer and its treatment. Minimising the impact of FT requires early assessment and intervention. General practice plays a significant role in the support of a person with cancer and may have an important role in the management of FT. The purpose of this study was to understand perspectives of general practitioners (GP) on addressing FT in the primary care setting, which may then help inform strategies to further support collaborative efforts to address FT. METHODS: A qualitative interpretive approach was utilised for this study. GPs were recruited through a GP conference and other professional networks using purposive, snowballing sampling techniques. Data collection continued until sufficient rich data had been obtained. Interviews were recorded and transcribed verbatim. The data were analysed using inductive analysis techniques. RESULTS: Twenty (n = 20) GPs participated in semi-structured in-depth telephone interviews. GPs identified that their role positions them well to provide some FT support, but there are limitations. Perceptions and philosophies about cancer management were drivers of referrals and financial conversations. Priorities for care of FT by GPs included improved cost information provision and accessible support. CONCLUSION: GPs can play an important role in helping to address FT associated with cancer and its treatments if supported with the right information.

Factors Explaining Socio-Economic Inequalities in Survival from Colon Cancer: A Causal Mediation Analysis.

BACKGROUND: Socio-economic inequalities in colon cancer survival exist in high-income countries, but the reasons are unclear. We assessed the mediating effects of stage at diagnosis, comorbidities, and treatment (surgery and intravenous chemotherapy) on survival from colon cancer. METHODS: We identified 2,203 people aged 15 to 79 years with first primary colon cancer diagnosed in Victoria, Australia, between 2008 and 2011. Colon cancer cases were identified through the Victorian Cancer Registry (VCR), and clinical information was obtained from hospital records. Deaths till December 31, 2016 (n = 807), were identified from Victorian and national death registries. Socio-economic disadvantage was based on residential address at diagnosis. For stage III disease, we decomposed its total effect into direct and indirect effects using interventional mediation analysis. RESULTS: Socio-economic inequalities in colon cancer survival were not explained by stage and were greater for men than women. For men with stage III disease, there were 161 [95% confidence interval (CI), 67-256] additional deaths per 1,000 cases in the 5 years following diagnosis for the most disadvantaged compared with the least disadvantaged. The indirect effects through comorbidities and intravenous chemotherapy explained 6 (95% CI, -10-21) and 15 (95% CI, -14-44) per 1,000 of these additional deaths, respectively. Surgery did not explain the observed gap in survival. CONCLUSIONS: Disadvantaged men have lower survival from stage III colon cancer that is only modestly explained by having comorbidities or not receiving chemotherapy after surgery. IMPACT: Future studies should investigate the potential mediating role of factors occurring beyond the first year following diagnosis, such as compliance with surveillance for recurrence and supportive care services.

Towards optimising chronic kidney disease detection and management in primary care: Underlying theory and protocol for technology development using an Integrated Knowledge Translation approach.

Worldwide, Chronic Kidney Disease (CKD), directly or indirectly, causes more than 2.4 million deaths annually with symptoms generally presenting late in the disease course. Clinical guidelines support the early identification and treatment of CKD to delay progression and improve clinical outcomes. This paper reports the protocol for the codesign, implementation and evaluation of a technological platform called Future Health Today (FHT), a software program that aims to optimise early detection and management of CKD in general practice. FHT aims to optimise clinical decision making and reduce practice variation by translating evidence into practice in real time and as a part of quality improvement activities. This protocol describes the co-design and plans for implementation and evaluation of FHT in two general practices invited to test the prototype over 12 months. Service design thinking has informed the design phase and mixed methods will evaluate outcomes following implementation of FHT. Through systematic application of co-design with service users, clinicians and digital technologists, FHT attempts to avoid the pitfalls of past studies that have failed to accommodate the complex requirements and dynamics that can arise between researchers and service users and improve chronic disease management through use of health information technology.

Barriers to employment of Australian cancer survivors living with geographic or socio-economic disadvantage: A qualitative study.

BACKGROUND: Opportunities for cancer survivors' employment can both reflect and perpetuate health inequities, as employment is an important social determinant of health. Socio-economic and geographic disadvantage is associated with greater difficulty finding work, but little is known about work needs of Australian cancer survivors living with disadvantage. OBJECTIVE: This study examined survivor and health-care professional (HCP) perspectives on barriers experienced by Australian cancer survivors experiencing disadvantage when attempting to remain at or return to work. METHOD: Focus groups and individual interviews were held with cancer survivors (N = 15) and oncology and primary HCPs (N = 41), focusing on communities at risk of disadvantage. Participants were asked about employment barriers and facilitators in general and in the context of disadvantage. Themes were identified using framework analysis. RESULTS: Geographic and socio-economic disadvantage resulted in specific individual- and system-level barriers. These related to distance from treatment and support services and limited availability and suitability of work for survivors living with geographic disadvantage, and limited availability, security, and flexibility of work and previous unemployment for survivors living with socio-economic disadvantage. Identified needs included system-level changes such as public and workplace-level education, legislative and policy changes, and better access to resources. CONCLUSIONS: Cancer survivors living with disadvantage experience limited access to flexible employment opportunities and resources, further perpetuating their disadvantage. Promotion of health equity for cancer survivors living with disadvantage requires systemic changes to support attempts to remain at/return to work. PATIENT OR PUBLIC CONTRIBUTION: This study included cancer survivors and HCPs as investigators, authors and participants.

Electronic clinical decision support tool for assessing stomach symptoms in primary care (ECASS): a feasibility study.

OBJECTIVE: To determine the feasibility of a definitive trial in primary care of electronic clinical decision support (eCDS) for possible oesophago-gastric (O-G) cancer. DESIGN AND SETTING: Feasibility study in 42 general practices in two regions of England, cluster randomised controlled trial design without blinding, nested qualitative and health economic evaluation. PARTICIPANTS: Patients aged 55 years or older, presenting to their general practitioner (GP) with symptoms associated with O-G cancer. 530 patients (mean age 68 years, 58% female) participated. INTERVENTION: Practices randomised 1:1 to usual care (control) or to receive a previously piloted eCDS tool for suspected cancer (intervention), for use at the discretion of the GPs, supported by a theory-based implementation package and ongoing support. We conducted semistructured interviews with GPs in intervention practices. Recruitment lasted 22 months. OUTCOMES: Patient participation rate, use of eCDS, referrals and route to diagnosis, O-G cancer diagnoses; acceptability to GPs; cost-effectiveness. Participants followed up 6 months after index encounter. RESULTS: From control and intervention practices, we screened 3841 and 1303 patients, respectively; 1189 and 434 were eligible, 392 and 138 consented to participate. Ten patients (1.9%) had O-G cancer. eCDS was used eight times in total by five unique users. GPs experienced interoperability problems between the eCDS tool and their clinical system and also found it did not fit with their workflow. Unexpected restrictions on software installation caused major problems with implementation. CONCLUSIONS: The conduct of this study was hampered by technical limitations not evident during an earlier pilot of the eCDS tool, and by regulatory controls on software installation introduced by primary care trusts early in the study. This eCDS tool needed to integrate better with clinical workflow; even then, its use for suspected cancer may be infrequent. Any definitive trial of eCDS for cancer diagnosis should only proceed after addressing these constraints. TRIAL REGISTRATION NUMBER: ISRCTN125595588.

An inverse stage-shift model to estimate the excess mortality and health economic impact of delayed access to cancer services due to the COVID-19 pandemic.

AIM: Decreased cancer incidence and reported changes to clinical management indicate that the COVID-19 pandemic has delayed cancer diagnosis and treatment. This study aimed to develop and apply a flexible model to estimate the impact of delayed diagnosis and treatment on survival outcomes and healthcare costs based on a shift in the disease stage at treatment initiation. METHODS: A model was developed and made publicly available to estimate population-level health economic outcomes by extrapolating and weighing stage-specific outcomes by the distribution of stages at treatment initiation. It was applied to estimate the impact of 3- and 6-month delays based on Australian data for stage I breast cancer, colorectal cancer, and lung cancer patients, and for T1 melanoma. Two approaches were explored to estimate stage shifts following a delay: (a) based on the relation between time to treatment initiation and overall survival (breast, colorectal, and lung cancer), and (b) based on the tumor growth rate (melanoma). RESULTS: Using a conservative once-off 3-month delay and considering only shifts from stage I/T1 to stage II/T2, 88 excess deaths and $12 million excess healthcare costs were predicted in Australia over 5 years for all patients diagnosed in 2020. For a 6-month delay, excess mortality and healthcare costs were 349 deaths and $46 million over 5 years. CONCLUSIONS: The health and economic impacts of delays in treatment initiation cause an imminent policy concern. More accurate individual patient data on shifts in stage of disease during and after the COVID-19 pandemic are critical for further analyses.

A Genomic Test for Colorectal Cancer Risk: Is This Acceptable and Feasible in Primary Care?

INTRODUCTION: Genomic tests can predict risk and tailor screening recommendations for colorectal cancer (CRC). Primary care could be suitable for their widespread implementation. OBJECTIVE: We aimed to assess the feasibility and acceptability of administering a CRC genomic test in primary care. METHODS: Participants aged 45-74 years recruited from 4 Australian general practices were offered a genomic CRC risk test. Participants received brief verbal information about the test comprising 45 CRC-associated single-nucleotide polymorphisms, before choosing whether to undertake the test. Personalized risks were given to testers. Uptake and knowledge of the genomic test, cancer-specific anxiety (Cancer Worry Scale), psychosocial impact (Multidimensional Impact of Cancer Risk Assessment [MICRA] score), and impact on CRC screening behaviour within 6 months were measured. RESULTS: In 150 participants, test uptake was high (126, 84%), with 125 (83%) having good knowledge of the genomic test. Moderate risk participants were impacted more by the test (MICRA mean: 15.9) than average risk participants (mean: 9.5, difference in means: 6.4, 95% confidence interval (CI): 1.5, 11.2, p = 0.01), but all scores were low. Average risk participants' cancer-specific anxiety decreased (mean differences from baseline: 1 month -0.5, 95% CI: -1.0, -0.1, p = 0.03; 6 months -0.6, 95% CI: -1.0, -0.2, p = 0.01). We found limited evidence for genomic testers being more likely to complete the risk-appropriate CRC screening than non-testers (41 vs. 17%, odds ratio = 3.4, 95% CI: 0.6, 34.8, p = 0.19), but some mediators of screening behaviour were altered in genomic testers. CONCLUSIONS: Genomic testing for CRC risk in primary care is acceptable and likely feasible. Further development of the risk assessment intervention could strengthen the impact on screening behaviour.

Variation in the initial assessment and investigation for ovarian cancer in symptomatic women: a systematic review of international guidelines.

BACKGROUND: Women with ovarian cancer can present with a variety of symptoms and signs, and an increasing range of tests are available for their investigation. A number of international guidelines provide advice for the initial assessment of possible ovarian cancer in symptomatic women. We systematically identified and reviewed the consistency and quality of these documents. METHODS: MEDLINE, Embase, guideline-specific databases and professional organisation websites were searched in March 2018 for relevant clinical guidelines, consensus statements and clinical pathways, produced by professional or governmental bodies. Two reviewers independently extracted data and appraised documents using the Appraisal for Guidelines and Research Evaluation 2 (AGREEII) tool. RESULTS: Eighteen documents from 11 countries in six languages met selection criteria. Methodological quality varied with two guidance documents achieving an AGREEII score ≥ 50% in all six domains and 10 documents scoring ≥50% for "Rigour of development" (range: 7-96%). All guidance documents provided advice on possible symptoms of ovarian cancer, although the number of symptoms included in documents ranged from four to 14 with only one symptom (bloating/abdominal distension/increased abdominal size) appearing in all documents. Fourteen documents provided advice on physical examinations but varied in both the examinations they recommended and the physical signs they included. Fifteen documents provided recommendations on initial investigations. Transabdominal/transvaginal ultrasound and the serum biomarker CA125 were the most widely advocated initial tests. Five distinct testing strategies were identified based on the number of tests and the order of testing advocated: 'single test', 'dual testing', 'sequential testing', 'multiple testing options' and 'no testing'. CONCLUSIONS: Recommendations on the initial assessment and investigation for ovarian cancer in symptomatic women vary considerably between international guidance documents. This variation could contribute to differences in the way symptomatic women are assessed and investigated between countries. Greater research is needed to evaluate the assessment and testing approaches advocated by different guidelines and their impact on ovarian cancer detection.

Decision support tools to improve cancer diagnostic decision making in primary care: a systematic review.

BACKGROUND: The diagnosis of cancer in primary care is complex and challenging. Electronic clinical decision support tools (eCDSTs) have been proposed as an approach to improve GP decision making, but no systematic review has examined their role in cancer diagnosis. AIM: To investigate whether eCDSTs improve diagnostic decision making for cancer in primary care and to determine which elements influence successful implementation. DESIGN AND SETTING: A systematic review of relevant studies conducted worldwide and published in English between 1 January 1998 and 31 December 2018. METHOD: Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched, and a consultation of reference lists and citation tracking was carried out. Exclusion criteria included the absence of eCDSTs used in asymptomatic populations, and studies that did not involve support delivered to the GP. The most relevant Joanna Briggs Institute Critical Appraisal Checklists were applied according to study design of the included paper. RESULTS: Of the nine studies included, three showed improvements in decision making for cancer diagnosis, three demonstrated positive effects on secondary clinical or health service outcomes such as prescribing, quality of referrals, or cost-effectiveness, and one study found a reduction in time to cancer diagnosis. Barriers to implementation included trust, the compatibility of eCDST recommendations with the GP's role as a gatekeeper, and impact on workflow. CONCLUSION: eCDSTs have the capacity to improve decision making for a cancer diagnosis, but the optimal mode of delivery remains unclear. Although such tools could assist GPs in the future, further well-designed trials of all eCDSTs are needed to determine their cost-effectiveness and the most appropriate implementation methods.

Benefits and harms of aspirin to reduce colorectal cancer risk: a cross-sectional study of methods to communicate risk in primary care.

BACKGROUND: New Australian guidelines recommend that GPs actively consider prescribing low-dose aspirin to patients aged 50-70 years to reduce their risk of developing colorectal cancer (CRC). Patients and GPs need to understand the relative benefits and harms to support informed decision making. AIM: To develop and examine different methods to communicate the benefits and harms of taking aspirin for CRC prevention. DESIGN AND SETTING: A cross-sectional, vignette study with patients aged 50-70 years consecutively recruited from general practices in Melbourne, Australia, between July and August 2018. METHOD: Summary estimates from meta-analyses of the effects of aspirin on the incidence of CRC, cardiovascular disease, gastrointestinal bleeding, and incidence rates in the Australian population to estimate outcomes in a hypothetical population of 10 000 people aged 50-70 years. These estimates were presented using four different risk communication formats. Participants were shown these different formats and asked if they would take aspirin to prevent CRC. RESULTS: A total of 313 participants were recruited (95.1% recruitment rate), of whom 304 completed the study. Most participants (71.7-75.3%) reported they would take aspirin irrespective of risk format presented. Bar charts (odds ratio [OR] 1.20, 95% confidence intervals [CI] = 1.01 to 1.44) and expected frequency trees (OR 1.18, 95% CI = 0.99 to 1.41) were more strongly associated with the intentions to take aspirin compared with icon arrays. Bar charts were most preferred for presenting risk information. CONCLUSION: A large proportion of participants in this study intended to take aspirin to reduce their CRC risk regardless of risk communication format. Bar charts and expected frequency trees were the preferred methods to present the benefits and harms of taking aspirin to prevent CRC.

Development of an intervention to expedite cancer diagnosis through primary care: a protocol.

BACKGROUND: GPs can play an important role in achieving earlier cancer diagnosis to improve patient outcomes, for example through prompt use of the urgent suspected cancer referral pathway. Barriers to early diagnosis include individual practitioner variation in knowledge, attitudes, beliefs, professional expectations, and norms. AIM: This programme of work (Wales Interventions and Cancer Knowledge about Early Diagnosis [WICKED]) will develop a behaviour change intervention to expedite diagnosis through primary care and contribute to improved cancer outcomes. DESIGN & SETTING: Non-experimental mixed-method study with GPs and primary care practice teams from Wales. METHOD: Four work packages will inform the development of the behaviour change intervention. Work package 1 will identify relevant evidence-based interventions (systematic review of reviews) and will determine why interventions do or do not work, for whom, and in what circumstances (realist review). Work package 2 will assess cancer knowledge, attitudes, and behaviour of GPs, as well as primary care teams' perspectives on cancer referral and investigation (GP survey, discrete choice experiment [DCE], interviews, and focus groups). Work package 3 will synthesise findings from earlier work packages using the behaviour change wheel as an overarching theoretical framework to guide intervention development. Work package 4 will test the feasibility and acceptability of the intervention, and determine methods for measuring costs and effects of subsequent behaviour change in a randomised feasibility trial. RESULTS: The findings will inform the design of a future effectiveness trial, with concurrent economic evaluation, aimed at earlier diagnosis. CONCLUSION: This comprehensive, evidence-based programme will develop a complex GP behaviour change intervention to expedite the diagnosis of symptomatic cancer, and may be applicable to countries with similar healthcare systems.

Revised Australian national guidelines for colorectal cancer screening: family history.

INTRODUCTION: Screening is an effective means for colorectal cancer prevention and early detection. Family history is strongly associated with colorectal cancer risk. We describe the rationale, evidence and recommendations for colorectal cancer screening by family history for people without a genetic syndrome, as reported in the 2017 revised Australian guidelines. Main recommendations: Based on 10-year risks of colorectal cancer, people at near average risk due to no or weak family history (category 1) are recommended screening by immunochemical faecal occult blood test (iFOBT) every 2 years from age 50 to 74 years. Individuals with moderate risk due to their family history (category 2) are recommended biennial iFOBT from age 40 to 49 years, then colonoscopy every 5 years from age 50 to 74 years. People with a high risk due to their family history (category 3) are recommended biennial iFOBT from age 35 to 44 years, then colonoscopy every 5 years from age 45 to 74 years. Changes in management as a result of the guidelines: By 2019, the National Bowel Cancer Screening Program will offer all Australians free biennial iFOBT screening from age 50 to 74 years, consistent with the recommendations in these guidelines for category 1. Compared with the 2005 guidelines, there are some minor changes in the family history inclusion criteria for categories 1 and 2; the genetic syndromes have been removed from category 3 and, as a consequence, colonoscopy screening is now every 5 years; and for categories 2 and 3, screening begins with iFOBT for people aged 40 and 35 years, respectively, before transitioning to colonoscopy after 10 years.

Benefits, Harms, and Cost-Effectiveness of Potential Age Extensions to the National Bowel Cancer Screening Program in Australia.

BACKGROUND: The Australian National Bowel Cancer Screening Program (NBCSP) is rolling out 2-yearly immunochemical fecal occult blood test screening in people aged 50 to 74 years. This study aimed to evaluate the benefits, harms, and cost-effectiveness of extending the NBCSP to younger and/or older ages. METHODS: A comprehensive validated microsimulation model, Policy1-Bowel, was used to simulate the fully rolled-out NBCSP and alternative strategies assuming screening starts at 40 or 45 years and/or ceases at 79 or 84 years given three scenarios: (i) perfect adherence (100%), (ii) high adherence (60%), and (ii) low adherence (40%, as currently achieved). RESULTS: The current NBCSP will reduce colorectal cancer incidence (mortality) by 23% to 51% (36% to 74%) compared with no screening (range reflects participation); extending screening to younger or older ages would result in additional reductions of 2 to 6 (2 to 9) or 1 to 3 (3 to 7) percentage points, respectively. With an indicative willingness-to-pay threshold of A$50,000/life-year saved (LYS), only screening from 50 to 74 years [incremental cost-effective ratio (ICER): A$2,984-5,981/LYS) or from 45 to 74 years (ICER: A$17,053-29,512/LYS) remained cost-effective in all participation scenarios. The number-needed-to-colonoscope to prevent a death over the lifetime of a cohort in the current NBCSP is 35 to 49. Starting screening at 45 years would increase colonoscopy demand for program-related colonoscopies by 3% to 14% and be associated with 55 to 170 additional colonoscopies per additional death prevented. CONCLUSIONS: Starting screening at 45 years could be cost-effective, but it would increase colonoscopy demand and would be associated with a less favorable incremental benefits-to-harms trade-off than screening from 50 to 74 years. IMPACT: The study underpins recently updated Australian colorectal cancer management guidelines that recommend that the NBCSP continues to offer bowel screening from 50 to 74 years.

Family history-based colorectal cancer screening in Australia: A modelling study of the costs, benefits, and harms of different participation scenarios.

BACKGROUND: The Australian National Bowel Cancer Screening Programme (NBCSP) was introduced in 2006. When fully implemented, the programme will invite people aged 50 to 74 to complete an immunochemical faecal occult blood test (iFOBT) every 2 years. METHODS AND FINDINGS: To investigate colorectal cancer (CRC) screening occurring outside of the NBCSP, we classified participants (n = 2,480) in the Australasian Colorectal Cancer Family Registry (ACCFR) into 3 risk categories (average, moderately increased, and potentially high) based on CRC family history and assessed their screening practices according to national guidelines. We developed a microsimulation to compare hypothetical screening scenarios (70% and 100% uptake) to current participation levels (baseline) and evaluated clinical outcomes and cost for each risk category. The 2 main limitations of this study are as follows: first, the fact that our cost-effectiveness analysis was performed from a third-party payer perspective, which does not include indirect costs and results in overestimated cost-effectiveness ratios, and second, that our natural history model of CRC does not include polyp sojourn time, which determines the rate of cancerous transformation. Screening uptake was low across all family history risk categories (64%-56% reported no screening). For participants at average risk, 18% reported overscreening, while 37% of those in the highest risk categories screened according to guidelines. Higher screening levels would substantially reduce CRC mortality across all risk categories (95 to 305 fewer deaths per 100,000 persons in the 70% scenario versus baseline). For those at average risk, a fully implemented NBCSP represented the most cost-effective approach to prevent CRC deaths (AUS$13,000-16,000 per quality-adjusted life year [QALY]). For those at moderately increased risk, higher adherence to recommended screening was also highly cost-effective (AUS$19,000-24,000 per QALY). CONCLUSION: Investing in public health strategies to increase adherence to appropriate CRC screening will save lives and deliver high value for money.