380 likes | 385 Views
This interactive introduction explores the relationship between quality of life and cost-effectiveness in healthcare, discussing key concepts like QALYs and TWiST. It also examines different healthcare programs and their cost-effectiveness.
E N D
Quality of life and Cost-Effectiveness An Interactive Introduction Prof. Jan J. v. Busschbach, Ph.D. Erasmus MC Medical Psychology and Psychotherapy Viersprong Institute for studies on Personality Disorders
I want to live in… Land A Land B Life expectancy 78.8 Quality of life 0.75 Cures catastrophic diseases • Life expectancy 80 • Quality of life 0.8 • Cures common diseases
I would spend money on… • High incidence • Many patients • High burden • Genetic cause • Effective treatment • Curtain outcome • Low incidence • Limited patients • Low burden • Behavioral cause • Non effective treatment • Uncertain outcome
I would spend money on… • Low incidence • Many patients • High burden • Genetic cause • Effective treatment • Curtain outcome • High incidence • Limited patients • Low burden • Behavioral cause • Non effective treatment • Uncertain outcome
New cancer therapy Symptoms Drug X Drug Y Survival days 300 400 Days sick of chemotherapy 10 150 Days sick of disease 100 30 TWiST 190 220
Time Without Symptoms of disease and subjective Toxic effects of treatment: TWiST • Richard Gelber • statistician • Count … • Days not sick from treatment • Days not sick from disease 6
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
TWiST: ignores differences in quality of life 0.0 Quality of life 1.0 • TWiST • Healthy = 1 • Sick (dead) = 0 • Q-TWiST • Quality of life adjusted TWiST • Make intermediate values • 1.0; 0.75; 0.50; 0.25; 0.00 • How to scale quality of life? 9
Uni-dimensional scale • Quality of life • World Health Organization, 1947 • “…. Health is physical, mental and social well-being and not merely the absence of disease or infirmity...” • But we need a uni-dimensional scale • Like temperature • IQ • Depression scale • School grad • So we need a overall judgment…
Visual Analogue Scale Normal health X Dead ?= • Does the scale fit Q-TWIST? • Is 2 days 0.5 Q = 1 day 1.0 Q ? 14
Interval / Ratio scale • Ratio or interval scale • Difference 0.00 and 0.80 must be 8 time higher than 0.10 • Uncommon in psychology
Time Trade-Off • Wheelchair • With a life expectancy: 50 years • How many years would you trade-off for a cure? • Max. trade-off: 10 years • QALY(wheel) = QALY(healthy) • Y * V(wheel) = Y * V(healthy) • 50 V(wheel) = 40 * 1.00 • V(wheel) = 0.80 16
Quality Adjusted Life Years (QALY) 1.00 X 0.00 0.5 x 80 = 40 QALYs 80 40 Life years • Example • Blindness • Time trade-off value is 0.5 • Life span = 80 years • 0.5 x 80 = 40 QALYs 17
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”
Q-TWiST = QALY • Several initiatives early seventies • Epidemiologist and health economists • Part of QALY concept • Quality Adjusted Life Years • QALY = Q-TWiST 19
Which health care program is the most cost-effective? • A new wheelchair for elderly (iBOT) • Special post natal care
www.ibotnow.com Dean Kamen Segway 22
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
Orphan drugs • Pompe disease • Classical form: infants €232.699/QALY; adults €2.800.000 • New estimates: 500.000/QALY; 17.000.000 • Low cost effectiveness but… • High burden • Low prevalence • Little own influence on disease • High consensus in the field • Coalition patient, industry, doctors and media • Low perceived incertainty
…it must be that QALYs are invalid We don’t like the results…
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)…
Chris Murray • WHO avoided QALY • (read: disliked QALYs) • (read disliked health economics) • But WHO in need of a measure of health… • Asked Havard… • “Anything… but QALY” • Chris Murray • School of Public Health • Worked outside • Health economics • Med Decision Making • DALY
Burden of disease: QALY lost = DALY (Disability adjusted life year) DALY QALY
Egalitarian Concerns:Burden of disease 1.0 Health 0.0 A B C
Costs/QALY as indicator of solidarity € 40.000 80 € 30.000 60 € 50.000 Levensjaen 40 20 0 A B C 33
Burden as criteria Pronk & Bonsel, Eur J Health Econom 2004, 5: 274-277
Costs/QALY versus Burden of disease € 80.000 € 60.000 € 40.000 € 20.000 € 0 X X X X X Burden of disease 35
Dutch Council for Public Health and Health Care (RvZ, 2006) 36
QALY debate • Fairness is the issue in the QALY debate • QALY measurement is the straw man • Complex metric discussion • Most debate about quality of life assessment • QALY are seen as unfair • But: QALYs are needed to operationalise fairness 37
Conclusion • Quality of life can be measured • Usual multidimensional • Unidimensional: QALYs • QALYs can validly be use in cost effectiveness research • Burden of disease is also a criterion • On need QALYs to measure burden