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Quality of life and Cost-Effectiveness An Interactive Introduction. Prof. Jan J. v. Busschbach, Ph.D. Erasmus MC Medical Psychology and Psychotherapy Viersprong Institute for studies on Personality Disorders. I want to live in…. Land A. Land B. Life expectancy 78.8 Quality of life 0.75 - PowerPoint PPT Presentation
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Quality of life and Cost-Effectiveness
An Interactive Introduction
Prof. Jan J. v. Busschbach, Ph.D.Erasmus MC
Medical Psychology and PsychotherapyViersprong Institute for studies on Personality Disorders
I want to live in…
Land A Life expectancy 80 Quality of life 0.8 Cures common
diseases
Land B Life expectancy 78.8 Quality of life 0.75 Cures catastrophic
diseases
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I would spend money on…
High incidenceMany patientsHigh burden Genetic causeEffective
treatmentCurtain outcome
Low incidenceLimited patientsLow burdenBehavioral causeNon effective
treatmentUncertain outcome
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I would spend money on…
Low incidenceMany patientsHigh burden Genetic causeEffective
treatmentCurtain outcome
High incidenceLimited patientsLow burdenBehavioral causeNon effective
treatmentUncertain outcome
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New cancer therapy
Symptoms Drug X Drug Y
Survival days 300 400Days sick of chemotherapy 10 150Days sick of disease 100 30TWiST 190 220
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Time Without Symptoms of disease and subjective Toxic effects of treatment: TWiST
Richard Gelber statistician
Count … Days not sick from treatment Days not sick from disease
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Fit new therapy in fixed budget
50 patients each year (per hospital) Drug x: 50 x euro 1.750 = euro 87.500 Drug y: 50 x euro 2.000 = euro 100.000
Drug budget for x or y = euro 50.000 Number of patient
• Drug x: euro 50.000 / 1.750 = 28.5 patients• Drug y: euro 50.000 / 2.000 = 25.0 patients
Survival in days• Drug x: 28.5 patients x 300 days = 8.550 days• Drug y: 25.0 patients x 400 days = 10.000 days
Survival in TWiST• Drug x: 28.5 patients x 190 TWiST = 5.415 days• Drug y: 25.0 patients x 220 TWiST = 5.500 days
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TWiST: ignores differences in quality of life
TWiST Healthy = 1 Sick (dead) = 0
Q-TWiST• Quality of life adjusted TWiST
Make intermediate values• 1.0; 0.75; 0.50; 0.25; 0.00
How to scale quality of life?
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0.0 Q
uality of lif
e 1
.0
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Uni-dimensional scale
Quality of life World Health Organization, 1947 “…. Health is physical, mental and social well-being and not
merely the absence of disease or infirmity...”
But we need a uni-dimensional scale Like temperature IQ Depression scale School grad
So we need a overall judgment…
Generic QoL Questions (SF-36)
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Complex interpretation
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Weighted index
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Visual Analogue Scale
Does the scale fit Q-TWIST? Is 2 days 0.5 Q = 1 day 1.0 Q ?
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Dead
Normal health
X?=
Interval / Ratio scale
Ratio or interval scale Difference 0.00 and 0.80 must be 8 time higher than 0.10
Uncommon in psychology
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Time Trade-Off
Wheelchair With a life expectancy: 50 years
How many years would you trade-off for a cure? Max. trade-off: 10 years
QALY(wheel) = QALY(healthy) Y * V(wheel) = Y * V(healthy) 50 V(wheel) = 40 * 1.00
V(wheel) = 0.80
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Example Blindness Time trade-off value is 0.5 Life span = 80 years 0.5 x 80 = 40 QALYs
Quality Adjusted Life Years (QALY)
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0.00
1.00
X
Life years40 80
0.5 x 80 = 40 QALYs
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QALY
Count life years Value (V) quality of life (Q)
V(Q) = [0..1] • 1 = Healthy• 0 = Dead
One dimension
Adjusted life years (Y) for value quality of life QALY = Y * V(Q)
• Y: numbers of life years• Q: health state• V(Q): the value of health state Q
Also called “utility analysis”
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Q-TWiST = QALY
Several initiatives early seventies Epidemiologist and health economists
Part of QALY concept Quality Adjusted Life Years QALY = Q-TWiST
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Area under the curve
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A new wheelchair for elderly (iBOT) Special post natal care
Which health care program is the most cost-effective?
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A new wheelchair for elderly (iBOT) Increases quality of life = 0.1 10 years benefit Extra costs: $ 3,000 per life year QALY = Y x V(Q) = 10 x 0.1 = 1 QALY Costs are 10 x $3,000 = $30,000 Cost/QALY = 30,000/QALY
Special post natal care Quality of life = 0.8 35 year Costs are $250,000 QALY = 35 x 0.8 = 28 QALY Cost/QALY = 8,929/QALY
Which health care program is the most cost-effective?
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QALY league table
Intervention $ / QALY GM-CSF in elderly with leukemia 235,958
EPO in dialysis patients 139,623
Lung transplantation 100,957
End stage renal disease management 53,513
Heart transplantation 46,775
Didronel in osteoporosis 32,047
PTA with Stent 17,889
STIP: Short-term inpatient psychotherapy 7,677
Breast cancer screening 5,147
Viagra 5,097
Treatment of congenital anorectal malformations 2,778
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10.000 Citations in PubMed
0
200
400
600
800
1000
1200
1970 1980 1990 2000 2010 2020
Publ
icat
ions
1980[pdat] AND (QALY or QALYs)
Orphan drugs
Pompe disease Classical form: infants €232.699/QALY; adults €2.800.000 New estimates: 500.000/QALY; 17.000.000
Low cost effectiveness but… High burden Low prevalence Little own influence on disease High consensus in the field
• Coalition patient, industry, doctors and media• Low perceived incertainty
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…it must be that QALYs are invalid
We don’t like the results…
In the past, much criticism
Cohen CB. Quality of life and the analogy with the Nazis. Journal of Medicine and Philosophy 8: 113-35, 1983.
Criticism remains
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….the strictly fascist essence of those QALYs (so-called
Quality-Adjusted Life Years)…
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Chris Murray WHO avoided QALY
(read: disliked QALYs) (read disliked health economics)
But WHO in need of a measure of health…
Asked Havard… “Anything… but QALY”
Chris Murray School of Public Health
Worked outside Health economics Med Decision Making
DALY
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Burden of disease: QALY lost = DALY (Disability adjusted life year)
DALY
QALY
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1.0
0.0A B C
Hea
lthEgalitarian Concerns:
Burden of disease
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80
0A B C
Leve
nsja
e nCosts/QALY as indicator of solidarity
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60
40
20
€ 50.000
€ 30.000
€ 40.000
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Burden as criteria
0
5
10
15
20
25
30
Accepted Rejected
High burden Low burden
Pronk & Bonsel, Eur J Health Econom 2004, 5: 274-277
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Costs/QALY versus Burden of disease
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€ 80.000
€ 60.000
€ 40.000
€ 20.000
€ 0
Burden of disease
X
XX
XX
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Dutch Council for Public Health and Health Care (RvZ, 2006)
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QALY debate
Fairness is the issue in the QALY debate QALY measurement is the straw man
Complex metric discussion Most debate about quality of life assessment
QALY are seen as unfair But: QALYs are needed to operationalise fairness
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Conclusion
Quality of life can be measured Usual multidimensional Unidimensional: QALYs
QALYs can validly be use in cost effectiveness research
Burden of disease is also a criterion On need QALYs to measure burden