overview of the eq-5d
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Overview of the EQ-5D. Purpose and origins of the descriptive system. 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. - PowerPoint PPT PresentationTRANSCRIPT
Overview of the EQ-5D
Purpose and origins of the descriptive system
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
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)
• Example – Blindness– Time trade-off value is 0.5– Life span = 80 years– 0.5 x 80 = 40 QALYs
Quality Adjusted Life Years (QALY)
0.00
1.00
X
Life years40 80
0.5 x 80 = 40 QALYs
Area under the curve
0 10 20 30 40 50 60 70 800
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Co-morbidityPsychotherapyNo psychotherapy
Life years
QAL
Y w
eigh
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Burden of disease (WHO): QALY lost = DALY Disability adjusted life year
DALY
QALY
QALY league table
Intervention $ / QALYGM-CSF in elderly with leukemia 235,958
EPO in dialysis patients 139,623Lung transplantation 100,957End stage renal disease management 53,513
Heart transplantation 46,775Didronel in osteoporosis 32,047
PTA with Stent 17,889Breast cancer screening 5,147
Viagra 5,097Treatment of congenital anorectal malformations 2,778
8
7000 Citations in PubMed1980[pdat] AND (QALY or QALYs)
0100200300400500600700800900
1000
1975 1980 1985 1990 1995 2000 2005 2010 2015
Publ
icat
ions
In search of a QoL value…
• Most controversy about QoL measure– In QALY analysis
• Uni-dimensional value– Like temperature– Like the IQ-test measures intelligence
• Ratio or interval scale– Difference 0.00 and 0.80…– … must be 8 time higher than 0.10
Unidimensional, ratio scales
• Two popular methods have these pretensions– Time trade-off– Standard gamble
• Two methods are less clear….– Visual analog scale– Paired comparison
• Conjoint analysis; DCE, etc
The Rosser & Kind Index
The Rosser & Kind index• One of the oldest valuation• 1978: Magnitude estimation
– Magnitude estimation PTO– N = 70: Doctors, nurses, patients and
general public• 1982: Transformation to “utilities”
– Other word for “value of QoL”
1985: High impact article
1985: High impact article
1985: High impact article– Survey at the celebration of 25 years of health
economics in the UK (HESG): chosen most influential article on health economics
Criticism on the Matrix
• Sensitivity– only 30 health states
• The compression of states in the high values• The unclear meaning of “distress”• The involvement of medical personnel• No clear way how to classify the patients
– into the matrix• Only British values
Value compression
New initiatives• Higher sensitivity (more then 30 states)• More and better defined dimensions• Other valuation techniques
– Standard Gamble, Time Trade-Off, Visual Analogue Scale
• Values of the general public• A questionnaire…
– to allow patients to ‘self classify’ themselves • An international standard
– to allow international comparisons– That is at that time “Europe”
EuroQoL Group
• First meeting 1987• Participants from
– UK, Finland, Sweden, The Netherlands• A common core instrument
– To allow international comparisons– To allow linking of international results
• Instrument should be small• Suitable for sever ill patients
– The emerging of high tech medicine, especially transplantation
The first EuroQol• Higher sensitivity (more then 30 states)
– 216 states• More and better defined dimensions
– 6 dimensions– Mobility; – Daily activity and self care;– Work performance– Family and leisure performance– Pain/discomfort– Present mood
• Other valuation techniques– Visual Analogue Scale
The first EuroQol
• Values of the general public– Values from general public– But also values from patients (!)
• A questionnaire– to allow patients to ‘self classify’ themselves
• A international standard – to allow international comparisons– That is at that time “Europe”
Direct utility assessment
Indirect utility assessment
First indirect values
Add the value of death
First international comparisons in 1988 with EQ-6D and VAS
0102030405060708090
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EuroQol 6-D health states
EQ-V
AS
valu
es
SwedenUkNetherlands
EQ-5D-3L Value Sets
TTO Value Sets VAS Value Sets
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1111
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1112
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2123
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3221
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2223
3
3332
1
3333
3
DenmarkGermanyJapanNetherlandsSpainUKUSAZimbabwe
-0.4
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1111
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BelgiumDenmarkFinlandNew ZealandSloveniaSpainUKEurope
Health State
Valu
e
Valu
e
Health State
Why indirect utility measures?
• Original: To avoid ‘strategic responses’– Patients pressure groups
• To avoid coping– Underestimating the value of health
• To allow complex utility assessments– Time Trade Off– Standard Gamble– Willingness to pay– Person Trade off– Paired comparisons (DCE)
• To allow for societal values of health states– Like costs: the societal perspective
Why indirect utility measures?
• Original: To avoid ‘strategic responses’– Patients pressure groups
• To avoid coping– Underestimating the value of health
• To allow complex utility assessments– Time Trade Off– Standard Gamble– Willingness to pay– Person Trade off– Paired comparisons (DCE)
• To allow for societal values of health states– Like costs: the societal perspective
Coping: can be a problem in the patient perspective….
• Stensman– Scan J Rehab Med
1985;17:87-99.• Scores on a visual
analogue scale– 36 subjects in a
wheelchair– 36 normal matched
controls• Mean score
– Wheelchair: 8.0– Health controls: 8.3
• Need for indirect valuation
Healthy
Death
Why indirect utility measures?
• Original: To avoid ‘strategic responses’– Patients pressure groups
• To avoid coping– Underestimating the value of health
• To allow complex utility assessments– Time Trade Off– Standard Gamble– Willingness to pay– Person Trade off– Paired comparisons (DCE)
• To allow for societal values of health states– Like costs: the societal perspective
Time Trade-Off
• TTO: alternative for VAS• 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
Health economics prefer TTO
• Visual analogue scale– No trade-off: no relation to QALY
• No interval proportions– Easy
• Time trade-Off– Trade-off: clear relation to QALY
• Interval proportions– Less easy
• Time consuming in patients• Need for indirect valuation
Why indirect utility measures?
• Original: To avoid ‘strategic responses’– Patients pressure groups
• To avoid coping– Underestimating the value of health
• To allow complex utility assessments– Time Trade Off– Standard Gamble– Willingness to pay– Person Trade off– Paired comparisons (DCE)
• To allow for societal values of health states– Like costs: the societal perspective
The economic perspective
• In a normal market: the consumer values count
• The patient seems to be the consumer– Thus the values of the patients….
• If indeed health care is a normal market… • But is it….?
Health care is not a normal market
• Supply induced demands• Government control
– Financial support (egalitarian structure)• Patient Consumer
– The patient does not pay• Consumer = General public
– Potential patients are paying• Health care is an insurance market
– A compulsory insurance market
Health care is an insurance market
• Values of benefit in health care have to be judged from a insurance perspective
• Who values should be used the insurance perspective?
Who determines the payments of unemployment insurance?
• Civil servant– Knowledge: professional– But suspected for strategical answers
• more money, less problems• identify with unemployed persons
• The unemployed persons themselves– Knowledge: specific– But suspected for strategical answers
• General public (politicians)– Knowledge: experience– Payers
Who’s values (of quality of life) should count in the health insurance?
• Doctors– Knowledge: professional– But suspected for strategical answers
• See only selection of patient• Identification with own patient
• Patients– Knowledge: disease specific– But suspected for strategical answers– But coping
• General public– Knowledge: experience– Payers– Like costs: the societal perspective
The general public should be informed…
• Valuing without knowledge makes no sense– Thyroid Eye Disease
• Give description of the disease– For instance in terms of the EQ-5D
A patient with bilateral thyroid eye disease with upper lid retraction and exophthalmos.
Why indirect utility measures?
• Original: To avoid ‘strategic responses’– Patients pressure groups
• To avoid coping– Underestimating the value of health
• To allow complex utility assessments– Time Trade Off– Standard Gamble– Willingness to pay– Person Trade off– Paired comparisons (DCE)
• To allow for societal values of health states– Like costs: the societal perspective
Indirect utility measrue
MOBILITY I have no problems in walking about I have some problems in walking about I am confined to bed SELF-CARE 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 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 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
Validated Questionnaires
• Describe health states• Have values from the general public
– Rosser Matrix– QWB– 15D– HUI Mark 2– HUI Mark 3– EuroQol EQ-5D