What do patients expect of preventive treatments and screening?

1. What do patients expect of preventive treatments and screening? Ben Hudson University of Otago Christchurch Abby Zarifeh University of Otago Dunedin Lorraine Young Pegasus Health Christchurch Elisabeth Wells University of Otago Christchurch

3. 10 year hip fracture risk Hip fractures avoided with treatment

4. 10 year bowel cancer deaths Bowel cancer deaths avoided with screening

5. Enthusiasm for interventions • Cardiovascular disease prevention - statins 20% of >50 yrs (Canterbury 2010) • Hip fracture prevention - bisphosphonates 4% of >50 yrs (Canterbury 2010) • Breast cancer screening 66% eligible women (NZ 2008-2009)

6. What do patients think these interventions do?

7. What’s expected – overseas evidence Breast cancer screening • Phone survey in US, Italy, UK, Switzerland

8. What’s expected? Breast cancer screening • Phone survey in US, Italy, Switzerland, UK1 • Screen 1,000 women for 10 years • 45% answered: prevent >80 deaths • Face-to-face interviews in 10 European countries2 • Screen 1,000 women for 10 years • 30% answered: 100-200 deaths avoided 1 Domenighetti G et al. Int J Epi 2003 October 1, 2003;32(5):816-21. 2 Gigerenzer G et al. JNCI September 2, 2009;101(17):1216-20.

9. What’s expected overseas – lipid lowering • 1,000 treated for 5 years, how many avoid a MI? • Mean answer: 531 Sweden Lytsy P, Westerling R. Patient Education and Counseling. 2007;67(1-2):143-50.

10. No answers • Fracture prevention • Bowel cancer screening • New Zealand • Minimum acceptable benefit

11. Questions • How effective do patients think these interventions are? • Screening: breast and bowel cancer • Prevention: CV disease and hip fracture • What is the minimum level of acceptable effectiveness? • Do socio-demographic factors predict responses?

12. What did we do? • Questionnaire • 5,000 people 50-70 yrs treated/screened for 10 years • Prevents: 1; 5; 50; 100; 500; 1000 events • Dec 2010 – Jan 2011 • 977 sent, 354 returned (36%)

13. Participants

14. 59% >10x achieved effect

15. 27%

16. 79% >10x achieved effect

17. 26%

18. 69%>5x achieved effect

19. 52%

20. 82% >5x achieved effect

21. 34%

22. Education

23. Education

24. Age

25. Age

26. Questions and implications • Perception of risk

27. Perception of risk • 145 women 40-50 years USA • Estimate risk of developing and dying of breast cancer in 10 next years • 37% overestimate risk of developing cancer >10-fold • 77% overestimate risk of dying >10-fold Black, WC et al (1995) Journal of the National Cancer Institute, 87(10), 720-731.

28. Questions and implications • Perception of risk • Informed consent • Decision aids • Effect on uptake • Targets and incentive payments

30. Enthusiasm for interventions • Cardiovascular disease prevention • Statins for primary prevention: • Mortality reduction – NNT 590 (one year) • Canterbury: 20% >50 yrs Rx in 2010 Taylor F et al. Statins for the primary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews 2011

31. Enthusiasm for interventions • Mammography • NNS: 337 – 2,500 over 10 years 1-3 • Uptake: 2008-2009 - 66% eligible women 4 1 Nelson HD et al. Ann Int Med November 17, 2009;151(10):727-37. 2 Gøtzsche P, Nielsen M. Cochrane Database of Systematic Reviews. 2011(1). 3 Kalager M, et al. NEJM. 2010;363(13):1203-10. 4 Page A, Taylor R. BreastScreen Aotearoa Independent Monitoring Report: Screening and Asessment of Women Attending BSA. 2009.