Evaluating options for a colorectal cancer screening programme in Ireland

1. Evaluating options for a colorectal cancer screening programme in Ireland Sharp L, Tilson L, Whyte S, Ó Céilleachair A*, Walsh C, Usher C, Tappenden P, Chilcott J, Staines A, Barry M & Comber H. Population-based cancer research in Ireland, Davenport Hotel September 4th 2009

2. Background • Over 2,000 new cases of colorectal cancer (CRC) are diagnosed in the Republic of Ireland each year. • 2nd most common cancer for both genders • Over 900 deaths per annum from CRC • On most key indicators Irish people fare worse than their European contemporaries • Higher incidence rates • Lower survival rates • Higher mortality amongst men • As population ages incidence is projected to increase

3. Opportunity for Screening • If caught early, CRC is very treatable • Survival much higher in Stage I-II disease • Screening in place for many European countries • Numerous modalities exist for early detection of CRC: • Guaic-based occult blood tests (gFOBT) • Immunochemical-based stool tests (FIT) • Flexible sigmoidoscopy

4. Cost-effectiveness analysis • Comparing the cost-effectiveness of two policies, A and B: • ICER = cost A – cost B/effect A – effect B • Effects may be in life-years gained (LYG) or quality-adjusted life years gained (QALYs) • The lower the ICER the “more” cost-effective A compared to B • €45,000 per QALY is an informal threshold of “cost-effectiveness” in an Irish setting

5. Evaluating Screening Options • Health technology assessment commissioned by HIQA • Evaluate using cost-effectiveness analysis competing alternative strategies for CRC screening in Ireland • Versus “No Screening” and also incrementally against each other • Estimate the likely resource burden of screening for a range of key services and also health outcomes over a ten year time horizon after the introduction of screening.

6. Methods • Core screening scenarios agreed with HIQA Expert Advisory Group: • biennial FIT at ages 55-74 • biennial gFOBT at ages 55-74, with reflex FIT • FSIG once only at age 60 • Supplementary scenarios also considered • Diagnostic investigations for postive screen test: colonoscopy or CT colonography • Surveillance for those with adenoma(s) ≥1cm removed: following current consensus recommendations (Atkins & Saunders, 2002)

7. Model • Markov model adapted from an existing model developed by collaborators in ScHARR • Natural history model of CRC • Hypothetical cohort of 55 year-olds tracked over their lifetime used for cost-effectiveness • Screening scenarios were then superimposed on this model • Outcome measures: Cost per QALY and cost per Life Year Gained (LYG) • Alternatives compared to “No Screening” and each other • Costs and outcomes discounted @ 4% • Healthcare payer perspective

8. Data • Model parameters • Natural history data • Data on the performance of tests • Cost data • Other data such as uptake • Data sourced from extensive literature reviews, information from existing screening programmes and expert opinion • Sensitivity analysis • One/multi way • Probabilistic sensitivity analysis

9. Performance and Uptake

10. Costs

11. Incremental Cost Effectiveness vs. “No Screening” Costs and outcomes discounted at 4% 1 Each incremental value compares value for that strategy to common baseline of no screening 2 gFOBT considered dominated by a combination of FIT and FSIG

12. Cost-Effectiveness Plane

13. CE Plane: Extended Dominance

14. Health Outcomes

15. Health Outcomes • Higher proportion of screen-detected with FIT (30% of all cancers, vs 14% with gFOBT and 3% with FSIG) • Under all scenarios, screen-detected cancers have more favourable stage distribution than those detected symptomatically/clinically • Sensitivity analysis found analysis to be robust. Findings did not change when using LYG as outcome measure

16. FSIG v FIT

17. But… FIT=faecal immunochemical test; FSIG= flexible sigmoidoscopy; gFOBT=guaiac-based faecal occult blood test 1 Over the entire lifetime of the cohort, therefore for gFOBT and FIT includes 10 screening rounds 2 Related to screening, diagnosis or surveillance 3 Complications associated with diagnostic and surveillance colonoscopy and, where relevant, FSIG 4 Major abdominal bleeding, requiring admission or intervention

18. Conclusions • Compared to “No Screening” all of the options considered could be termed highly cost-effective. • Biennial FIT 55-74 optimal strategy as it provides greater health gains at an acceptable ICER • Not insignificant resource considerations and complications need to be borne in mind

19. Thank You