Discounting a prevention programme

HPV vaccination at age 14. The cost falls this year; the health arrives decades later. Move the rate and watch what that does.

—
cost per QALY gained, at the rate you have set
UndiscountedAt this rate
Cost per girl——
QALYs gained——
Retained——
0%5%10%

The Indian Reference Case sets 3% for both costs and outcomes, beyond one year, and asks you to vary it from 0% to 5% in sensitivity analysis and to report undiscounted values as well.

Watch the two “retained” figures diverge. The cost is paid now, so discounting barely touches it; the health arrives from age 30 onward, so it is discounted hard. That asymmetry is not a quirk of arithmetic. It is why every prevention programme looks worse than a treatment at the same rate, and it is the reason some economists argue health should be discounted at a lower rate than money. The counter-argument is that a lower rate for health implies you should always wait, because delaying a programme makes it look better. Neither side has won.

The figures here are illustrative: a ₹1,500 cost at age 14 and a small annual health gain from age 30 to 70, chosen to show the mechanism cleanly, not extracted from any paper. Compare what you get at 3% with the ₹5,693–₹31,511 per QALY that Chauhan and colleagues report for HPV vaccination in India.