What do patients expect of preventive treatments and screening?

Ben Hudson University of Otago ChristchurchAbby Zarifeh University of Otago DunedinLorraine Young Pegasus Health ChristchurchElisabeth Wells University of Otago Christchurch

10 year hip fracture risk

Hip fractures avoided with treatment

10 year bowel cancer deaths

Bowel cancer deaths avoided with screening

Enthusiasm for interventions

• Cardiovascular disease prevention - statins20% of >50 yrs (Canterbury 2010)

• Hip fracture prevention - bisphosphonates4% of >50 yrs (Canterbury 2010)

• Breast cancer screening66% eligible women (NZ 2008-2009)

What do patients think these interventions do?

What’s expected – overseas evidence Breast cancer screening

• Phone survey in US, Italy, UK, Switzerland

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.

What’s expected overseas – lipid lowering

• 1,000 treated for 5 years, how many avoid a MI?

• Mean answer: 531

Lytsy P, Westerling R. Patient Education and Counseling. 2007;67(1-2):143-50.

Sweden

No answers

• Fracture prevention• Bowel cancer screening• New Zealand• Minimum acceptable benefit

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?

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%)

ParticipantsMale 198 (56%)

Female 156 (44%)

NZ European 317 (90%)

Māori 10 (3%)

Pacific Island 1 (0.3%)

Asian 2 (0.6%)

Other 24 (7%)

Mean age (years) (sd) 59.7 (5.7)

Lower 108 (31%)

Higher 246 (69%)

Had a mammogram (women) 146 (94%)

59% >10x achieved effect

27%

79% >10x achieved effect

26%

69%>5x achieved effect

52%

82% >5x achieved effect

34%

EducationBreast cancer

screeningBowel cancer

screeningHip fracture CVD

OR (95%) OR (95%) OR (95%) OR (95%)Estimated effect

Higher vs lower education 0.6 (0.4-1.0) 0.5 (0.3-0.8) 0.7 (0.5-1.1) 0.6 (0.4-0.9)

P 0.03 0.002 0.15 0.026

EducationBreast cancer

screeningBowel cancer

screeningHip fracture CVD

OR (95%) OR (95%) OR (95%) OR (95%)Estimated effect

Higher vs lower education 0.6 (0.4-1.0) 0.5 (0.3-0.8) 0.7 (0.5-1.1) 0.6 (0.4-0.9)

P 0.03 0.002 0.15 0.026Minimum acceptable benefit

Higher vs lower education 0.4 (0.2-0.6) 0.4 (0.2-0.6) 0.4 (0.3-0.6) 0.4 (0.2-0.5)

P <0.0001 <0.0001 <0.0001 <0.0001

AgeBreast cancer

screeningBowel cancer

screeningHip fracture CVD

OR (95%) OR (95%) OR (95%) OR (95%)Estimated effect

50-54 0.6 (0.3-1.0) 0.6 (0.3-1.0) 1.2 (0.7-2.1) 0.8 (0.4-1.3)55-59 0.6 (0.3-1.1) 0.5 (0.3-0.8) 1.0 (0.6-1.7) 0.5 (0.3-1.0)60-64 0.9 (0.5-1.6) 0.7 (0.4-1.3) 1.2 (0.7-2.1) 0.9 (0.5-1.6)65-70 1.0 1.0 1.0 1.0P 0.12 0.04 0.76 0.12

AgeBreast cancer

screeningBowel cancer

screeningHip fracture CVD

OR (95%) OR (95%) OR (95%) OR (95%)Estimated effect

50-54 0.6 (0.3-1.0) 0.6 (0.3-1.0) 1.2 (0.7-2.1) 0.8 (0.4-1.3)55-59 0.6 (0.3-1.1) 0.5 (0.3-0.8) 1.0 (0.6-1.7) 0.5 (0.3-1.0)60-64 0.9 (0.5-1.6) 0.7 (0.4-1.3) 1.2 (0.7-2.1) 0.9 (0.5-1.6)65-70 1.0 1.0 1.0 1.0P 0.12 0.04 0.76 0.12Minimum acceptable benefit

50-54 0.4 (0.2-0.7) 0.4 (0.2-0.7) 0.6 (0.4-1.1) 0.5 (0.3-0.9)55-59 0.8 (0.4-1.3) 0.7 (0.4-1.2) 1.0 (0.6-1.8) 1.0 (0.6-1.8)60-64 1.5 (0.9-2.5) 1.1 (0.7-1.9) 1.2 (0.7-2.0) 1.3 (0.8-2.3)65-70 1.0 1.0 1.0 1.0P <0.0001 0.0008 0.11 0.006

Questions and implications

• Perception of risk

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.

Questions and implications

• Perception of risk• Informed consent• Decision aids• Effect on uptake • Targets and incentive payments

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

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.