overview of the eq-5d

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

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Life years40 80

0.5 x 80 = 40 QALYs

Area under the curve

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Life years

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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– 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

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SwedenUkNetherlands

EQ-5D-3L Value Sets

TTO Value Sets VAS Value Sets

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DenmarkGermanyJapanNetherlandsSpainUKUSAZimbabwe

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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

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

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

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.

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

overview of the eq-5d

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