The QALY debate
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Transcript The QALY debate
The QALYs debate
Prof.
dr. Jan J.V. Busschbach, Ph.D.
Erasmus MC
Institute for Medical Psychology and Psychotherapy
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Health Economics
Comparing
different allocations
Should we spent our money on
• Wheel chairs
• Screening for cancer
Comparing costs
Comparing outcome
Outcomes
must be comparable
Make a generic outcome measure
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Outcomes in health economics
Specific
outcome are incompatible
Allow only for comparisons within the specific field
• Clinical successes: successful operation, total cure
• Clinical failures: “events”
“Hart failure” versus “second psychosis”
Generic
outcome are compatible
Allow for comparisons between fields
• Life years
• Quality of life
Most
generic outcome
Quality adjusted life year (QALY)
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Quality Adjusted Life Years
(QALY)
Example
Blindness
Time trade-off value is 0.5
Life span = 80 years
0.5 x 80 = 40 QALYs
1.00
X
0.5 x 80 = 40 QALYs
0.00
40
80
Life years
4
Time Trade-Off
TTO
Wheelchair
With a life expectancy: 50 years
How
many years would you trade-off for a
cure?
Max. trade-off is 10 years
QALY(wheel)
= QALY(healthy)
Y * V(wheel) = Y * V(healthy)
50 V(wheel) = 40 * 1
V(wheel)
= .8
5
Standard Gamble
SG
Wheelchair
Life
expectancy is not important here
How much are risk on death are you prepared
to take for a cure?
Max. risk is 20%
wheels = (100%-20%) life on feet
V(Wheels) = 80% or .8
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1970
Area under the curve
1
QALY weights
0.9
0.8
0.7
0.6
Co-morbidity
0.5
Psychotherapy
0.4
No psychotherapy
0.3
0.2
0.1
0
0
10
20
30
40
50
60
70
80
Life years
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Which health care program is
the most cost-effective?
A new wheelchair for elderly (iBOT)
Special post natal care
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www.ibotnow.com
Dean Kamen
Segway
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Which health care program is
the most cost-effective?
A new wheelchair for elderly (iBOT)
Increases quality of life = 0.1
10 years benefit
Extra costs: $ 4,000 per life year
QALY = Y x V(Q) = 10 x 0.1 = 1 QALY
Costs are 10 x $4,000 = $30,000
Cost/QALY = 40,000/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
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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
Breast cancer screening
5,147
Viagra
5,097
Treatment of congenital anorectal malformations
2,778
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Milton Weinstein
In
the face of uncertainty … and fear
The decision will be made, if not actively then
by default
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7000 Citations in PubMed
Publications
1980[pdat] AND (QALY or QALYs)
1000
900
800
700
600
500
400
300
200
100
0
1975
1980
1985
1990
1995
2000
2005
2010
2015
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QALY = Utility: Welfare theory
QALY
can be see as the ‘value of health’
The value of a good or service: “utility”
Also called “nut” (Dutch)
Welfare
theory: maximize utility
Maximize QALY
Do
we want to maximize QALY?
Doubtful…
15
Is the utility scale valid?
1.0
0.0
A
B
C
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Critique
We
do not maximize QALY
But nevertheless we want to maximize utility
• By (economic) definition..
That means:
QALYs
measured utility in an invalid way
Life years is not the problem, thus…
It
must be the validity of quality of life
assessment…
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We don’t like the results…
…it
must be that QALYs are invalid
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
….the strictly fascist essence
of those QALYs (so-called
Quality-Adjusted Life Years)…
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Burden as criteria
30
25
20
15
10
5
0
Accepted
High burden
Rejected
Low burden
Pronk & Bonsel, Eur J Health Econom 2004, 5: 274-277
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Person Trade-Off
Values
between patients
Not ‘within’ a patient like SG, TTO and VAS
Better equipped for QALY?
V(Q)
= 1 - (A / B)
For instance:
V(Q) = 1 - (100/300)
V(Q) = 1 - 0.33
V(Q) = 0.67
100 persons
additionally 1 healthy year
?? persons 1 year
free from disease Q
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TTO does not correlate with PTO
1.0
TTO
Utilities
0.8
PTO
0.6
0.4
0.2
0.0
Qu
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PTO and it’s psychometrics
Paul
Kind:
If we look at TTO and PTO...
we see that one of them is wrong
If
we look at PTO alone...
We still see that one of them is wrong...
1,0
0,8
TTO
PTO
PTO
0,6
Utilities
PTO is not a quick fix
0,4
0,2
0,0
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Falsification even with life years
A
B
C
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Utility?
1.0
0.0
A
B
C
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Utility
Utility
Total benefit
Including distribution
Also called “Nut” (Dutch)
Quality of life might be part of total benefit
QALYs do not include distribution
But
it is said that ‘Standard Gamble’
measures utilities!
Van N-M utilities by definition utility
But in SG only “health for your self”
Does not include distribution
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Costs/QALY as indicator of solidarity
€ 40.000
€ 30.000
€ 50.000
A
B
C
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Costs/QALY versus Burden of disease
X
€ 80.000
X
€ 60.000
X
€ 40.000
X
€ 20.000
€
X
0
Burden of disease
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Dutch Council for Public Health and
Health Care (RvZ, 2006)
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If a medical treatment costs >€80,000 to give one patient one
extra life year of good quality, it should not be reimbursed in the
basic health care insurance
Council advises the Minister of Health to use this limit in order to
keep the budget of health care under control; They realize the
topic is controversial.
Chris Murray
WHO avoid QALY
Havard
Worked outside
DALY
Person Trade-Off
School of Public Health
Health economics
Med Decision Making
Reinvented
32
Burden of disease:
QALY lost = DALY (Disability adjusted life year)
DALY
QALY
33
Burden of disease expressed as
“QALY lost” = DALY
Disability
adjusted life years
The inverse of QALY
Used by the WHO
Expresses
burden of disease
Measure of priority
More burden, more investment
QALY
lost (DALY) = Measure of solidarity
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QALY: both for effectiveness
and solidarity
Evaluations
assess cost-effectiveness in term
of cost/QALY
But many decisions can not be explained by
cost/QALY
Explanation in terms of fairness
People disagree with distributional implications of QALY
maximisation
Fairness
is burden of disease
Burden of disease is QALY lost (DALY)
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QALY debate
Fairness
is the issue in the QALY debate
QALY measurement is the straw man
Complex metric discussion
QALYs are needed to operationalize fairness
Most
debate about quality of life assessment
Again as straw man
But also within the metric debate of QALY
36
Reimbursement arguments
Burden of disease
Effects
Cost effectiveness
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Alternative applications
Link
to out of pocket payments
Greater out of pocket payments for conditions with lower
proportional shortfall
E.g. France and Belgium
For
example:
No reimbursement for the mildest conditions, such as
common cold, acute tonsillitis, acute bronchitis,
onychomycosis, tinea pedis
Partial reimbursement for conditions mild to moderate
conditions: Haemorrhoids, candidiasis, gastritis, osteoporosis,
erectile dysfunction, acne conglobata
Etc.
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Take home message
Quality
of life assessment and health
assessment is crucial
Not only to estimate health gains (efficiency)
But
also to estimate need (equity)
It is not the measurement of quality of life
but the efficiency/equity trade-off which heats up the debate
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