Intro QALY & need assessment
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Transcript Intro QALY & need assessment
Cost-Effectiveness in Medicine
An Interactive Introduction
Jan
J. v. Busschbach, Ph.D.
Erasmus MC
• Institute for Medical Psychology and Psychotherapy
Viersprong Institute for studies on Personality Disorders
Presentations
can be found at:
www.busschbach.nl
1
New cancer therapy
Symptoms
Drug X
Drug Y
Survival days
Days sick of chemotherapy
Days sick of disease
TWiST
300
10
100
190
400
150
30
220
2
Time Without Symptoms of disease and
subjective Toxic effects of treatment
TWiST
Developed by Richard Gelber (statistician)
In
search for a typical “cancer”
problem
Often prolonged life but also a reductions in
quality of life
• At the beginning (side effects)
• At the end
Only count the days without symptoms of disease
and subjective toxic effects of the treatment
3
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
4
TWiST: ignores differences
in quality of life
TWiST
Healthy = 1
Sick (dead) = 0
There
is more to life than sick/health
Make intermediate values
Q-TWiST
• Quality of life adjusted adjusted TWiST
How
to scale quality of life?
5
Value a health state
Wheelchair
Some problems in walking about
Some problems washing or dressing
Some problems with performing usual activities
Some pain or discomfort
No psychosocial problems
6
Time Trade-Off
QALY:
Quality Adjusted Life Years
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)
= .80
7
EuroQol EQ-5D:
of the shelf QALY value
MOBILITY
SELF-CARE
I have no problems with performing my usual activities
I have some problems with performing my usual activities
I am unable to perform my usual activities
PAIN/DISCOMFORT
I have no problems with self-care
I have some problems washing or dressing myself
I am unable to wash or dress myself
USUAL ACTIVITIES (e.g. work, study, housework family or
leisure activities)
I have no problems in walking about
I have some problems in walking about
I am confined to bed
I have no pain or discomfort
I have moderate pain or discomfort
I have extreme pain or discomfort
ANXIETY/DEPRESSION
I am not anxious or depressed
I am moderately anxious or depressed
I am extremely anxious or depressed
8
In health economics:
Q-TWiST = 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”
9
Which health care program is
the most cost-effective?
A new wheelchair for elderly (iBOT)
Special post natal care
10
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: $ 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
11
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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Egalitarian Concerns:
Burden of disease
1.0
0.0
A
B
C
13
Implications shifting threshold
QALY
are weighted
Weighted QALYs are maximized
Health is no longer the only thing maximized
Health
status population will drop
Differences in health will drop
Egalitarian consideration are incorporated
Burden
of disease becomes a criteria
Equity
14
CE-ratio by equity
15
Conclusion
Cost
effectiveness in medicine can be
measured
Burden of disease is also a criterion
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