Why use the EQ-5D?

What are the alternatives?

What are the alternatives for Direct valuation?

• Other VAS• Time Trade-Off• Standard Gamble• Willingness to pay• Difficult…

– Paired comparisons

– DCE etc

Visual Analogue Scale

• VAS– Also called “category scaling”– From psychological research

• “How is your quality of life?”• “X” marks the spot

– Rescale to [0..1]• Different anchor point possible:

– Normal health (1.0) versus dead (0.0)– Best imaginable health versus

worse imaginable health Dead

Normal health

X

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

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 .80

Willingness to pay• Cost benefit analyis• Revealed preferences

– Look in market how much subject are willing to pay

– Different situations give different results

– Weighted by in income• Conclusion:

– the validity of cost benefit analysis is not sufficient

Alternatives for indirect measurements

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 Rosser & Kind EuroQol EQ-5D www.euroqol.org QWB SF-36 (SF-6D) www.sf-36.org HUI Mark 2 HUI Mark 3 www.healthutilities.com 15D www.15d-instrument.net

The Rosser & Kind Index

The Rosser & Kind index

• Criticism on the Rosser & Kind index– Sensitivity (only 30 health states)

• New initiatives– Higher sensitivity (more then 30 states)

• EuroQol Group– EQ-5D-3L and the EQ-5D-5L

• McMaster University– Health Utility Index 2 & 3

• SF-36– SF-6D

Health Utility Index

• Developed from pediatric care– Strong proxy versions

• Symptom driven: – “Outside the skin” instead of “inside the skin”

• EQ-5D: “problems with daily activity”• HUI: “Unable to read ordinary newsprint…”

• Commercial– All user have to pay

• 35 Translations

HUI 2

HUI 3

Increasing number of health states

Questionnaire Number of health state Rosser 30 EuroQol EQ-5D 243 QWB 2,200 SF-36 (SF-6D) 9,000 HUI Mark 2 24,000 HUI Mark 3 972,000 15D 3,052,000,000

No longer value all states

• Impossible to value all health states– If one uses more than 30 health states

• Estimated the value of the other health states with statistical techniques– Statistically inferred strategies

• Regression techniques• EuroQol, Quality of Well-Being Scale (QWB)

– Explicitly decomposed methods• Multi Attribute Utility Theory (MAUT)• Health Utility Index (HUI)

Statistically inferred strategies

• Value a sample of states empirically• Extrapolation

– Statistical methods, like linear regression– 11111 = 1.00– 11113 = .70– 11112 = ?

Statistically inferred strategies

• EuroQol– EQ-5D: 5 dimensions of health– 245 health states

• Quality of Well-Being scale (QWB)– 4 dimensions of health– 2200 health states plus 22 additional symptoms

• SF-36– SF-6D: 6 dimensions of health– 18.000 health states

Explicitly Decomposed Methods

• Value dimensions separately– Between the dimensions– What is the relative value of:

• Mobility…... 20%• Mood……….. 15%• Self care.… .24%

• Value the levels– Within the dimensions– What is the relative value of

• Some problems with walking…..80%• Much problems with walking……50%• Unable to walk………..……………….10%

• 21111 = 1 - (0.20 x (1.00 - 0.80)) = 0.96

Explicitly Decomposed Methods

• Combine values of dimensions and levels with specific assumptions– Multi Attribute Utility Theory (MAUT)

• Mutual utility independence• Structural independence

Explicitly Decomposed Methods

• Health Utilities Index (Mark 2 & 3)– Torrance at McMaster– 8 dimensions– Mark 2: 24.000 health states– Mark 3: 972.000 health states

• The 15-D– Sintonen H.– 15 dimensions– 3,052,000,000 health states (3 billion)

More health states, higher sensitivity ? (1)

• EuroQol criticised for low sensitivity– Low number of dimensions

• Development of EQ-5D plus cognitive dimension– Low number of levels (3)

• Gab between best and in-between level

More health states, higher sensitivity ? (2)

• Little published evidence– Sensitivity EQ-5D < SF-36

• Compared as profile, not as utility measure– Sensitivity EQ-5D HUI

• Sensitivity the number of health states– How well maps the classification system the

illness?– How valid is the modelling?– How valid is the valuation?

More health states, more assumptions

• General public values at the most 50 states• The ratios empirical (50) versus extrapolated

– Rosser & Kind 1:1– EuroQol 1:5– QWB 1:44– SF-36 1:180– HUI (Mark III)1:19,400– 15D 1:610,000,000

• What is the critical ratio for a valid validation?

Conflicting evidence sensitivity SF-36

Liver transplantation, Longworth et al., 2001

SF-36 as utility instrument

• Transformed into SF6D• SG• N = 610• Inconsistencies in model

– 18.000 health states– regression technique stressed to the edge

• Floor effect in SF6D

Collapsing levels SF-6D

• Many levels are taken together– If PF=2 decrement: - 0.056– If PF=3 decrement: - 0.056

– If RL=2 decrement: - 0.073– If RL=3 decrement: - 0.073– If RL=4 decrement: - 0.073

SF-6D loses a lot of levels• Levels clas.system and actual levels

– PF 6 5– RL 4 2– SF 5 5– PN 6 5– MH 5 4– VI 5 3

• Levels in clas. system: 18.000– 6x4x5x6x5x5

• Actual levels: 480– 5x2x5x5x4x3

Some levels in the SF-6D do not work…

Dimension: Physical Functioning (PF) If PF=1 decrement: 0 If PF=2 decrement: - 0.056 If PF=3 decrement: - 0.056 If PF=4 * decrement: - 0.072 If PF=5 * decrement: - 0.080 If PF=6 * decrement: - 0.134 Dimension: Role Limitations (RL) If RL=1 decrement: 0 If RL=2 decrement: - 0.073 If RL=3 * decrement: - 0.073 If RL=4 * decrement: - 0.073

EQ-5D• Strong punts

– Very sensitive in the low– Measures subjective burden (inside the skin)– Low administrative burden– Many translations– Cheap– Most used QALY questionnaire– Most international validations

• Weak points– Only there levels per dimensions– Insensitive in the high regions

HUI

• Strong punts– Sensitive– Measures objective burden (outside the skin)– Well developed proxy versions– Well developed child versions

• Weak points– Expensive– Only a few valuation studies

SF-6D

• Strong punts– Probably sensitive in the high regions– Often already include in trials (SF-36)– Many translations

• Weak points– Insensitive in the low regions– Only a few validation study– Might be expensive

Conclusions

• More states better sensitivity• The three leading questionnaires

– have different strong and weak points