Part A: Incremental Cost-Effectiveness Ratio

Please note that any change in a probability affects two probabilities, as the sum of the probabilities at a chance node must sum to 1.0.

1. Expected cost of supportive care

2. Expected cost of vaccine

3. Effectiveness of supportive care

4. Effectiveness of the vaccine

5. ICER

Part B: ICER with Discounting

Outcomes that occur in the future are often discounted back to the present. Make the following change to the calculation of the effectiveness of supportive care and the vaccine: apply a discount rate of 3% (0.03) to future person-years. Discount these back to a present value at age 95. Given this change recalculate:

6. Effectiveness of supportive care

7. Effectiveness of the vaccine

8. ICER

Original Value for value assignment Unvaccinated branch Pr(remains well) 0.90 0.85 Pr(recovers, so doesn't see doctor) 0.80 0.75 Cost of seeing doctor $100 $120 Pr(recovers, given that sees doctor) 0.99 0.96 Cost of hospitalization $5000 $7000 Vaccinated branch Cost of vaccine $50 $80 Pr(remains well) 0.97 0.94 Pr(recovers, so doesn't see doctor) 0.90 0.88 Cost of seeing doctor $100 $120 Pr(recovers, given that sees doctor) 0.999 0.98 Cost of hospitalization $5000 $7000\f