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.