A cancer treatment extends life by 3 years with a health utility of 0.4 (severe side effects). An alternative treatment extends life by 2 years with a utility of 0.8 (mild side effects). Which produces more QALYs?
AThe first treatment: 3 × 0.4 = 1.2 QALYs
BThe second treatment: 2 × 0.8 = 1.6 QALYs
CThey are equal because one trades quantity for quality
DQALYs cannot be calculated without knowing the cost
QALYs multiply years by utility: 3 × 0.4 = 1.2 vs. 2 × 0.8 = 1.6. The shorter-lived treatment with better quality produces more QALYs. This illustrates the core value of the QALY metric — it captures the intuition that quality matters, not just duration. A patient might rationally prefer 2 good years to 3 miserable ones, and the QALY framework formalizes this preference. Of course, individual patients may value quality and quantity differently, which is one limitation of using population-average utilities.
Question 2 Short Answer
Health utilities used in QALY calculations are typically elicited from the general public rather than from patients actually living with the condition. Why?
Think about your answer, then reveal below.
Model answer: The general public perspective is used because QALYs inform societal resource allocation decisions — the question is how much society should invest in treating a condition, and society (through taxes or insurance) is paying. Patients who have adapted to their condition often rate their quality of life higher than the general public would predict (disability paradox or hedonic adaptation), which would reduce the apparent benefit of treating the condition and bias allocation away from conditions that people adapt to well. Using public preferences ensures the values reflect societal willingness to pay rather than patient adaptation.
This is controversial. Patient advocates argue that actual patients' valuations are more authentic, while health economists argue that using adapted patient values would systematically undervalue interventions for conditions that patients learn to live with. The choice of whose values to use is fundamentally a normative question about whose perspective should drive resource allocation.
Question 3 True / False
DALYs and QALYs are conceptual inverses: QALYs measure health gained, DALYs measure health lost. A disease that causes 1,000 DALYs in a population is equivalent to losing 1,000 years of perfect health.
TTrue
FFalse
Answer: True
DALYs = Years of Life Lost (YLL) from premature mortality + Years Lived with Disability (YLD) weighted by disability severity. They measure the burden of disease — the gap between the current health of a population and the ideal of living to old age in perfect health. QALYs measure the health gained from an intervention. A treatment that prevents 1,000 DALYs is equivalent to producing 1,000 QALYs (approximately — the two metrics use slightly different disability weights and reference points, but the conceptual relationship holds).