Exercises: Calculate the result for each exercise (show your work to earn points when the answer is incorrect; if you prefer to use paper, please ask for it) (1.5 points each).

1. A patient receives a flu shot (treatment intervention) which leads to one of the following events: Remains Well or Becomes Ill.

Suppose that the flu shot had a probability of Remains Well = 0.85 (or 85%).

a. What is the probability of Becomes Ill?

Suppose further that the probability a patient Recovers is 0.75 (or 75%).

b. What is the probability the patient Sees Doctor?

c. Draw a Decision Analysis Model that shows the probabilities of outcomes for patients receiving the flu shot.

2.  An average 30-year-old has a life expectancy of 60 years.

a. What are the hand calculated years lost due to death at age 30?

b. If 325 people die each year from the flu. How many lives can be saved with a flu shot with a 0.9 efficacy?

c. A medical intervention adds 20 years of life with an HRQL of .5. How many years of health (or QALY's) are gained with the medical intervention?

3. New treatment for maniasis has an unknown impact on the overall quality of life but improves life expectancy by 2 years over the 7-year span of treatment.

• The average person with the disease has a 5-year life expectancy.
• The average HRQL of people with maniasis is 0.4.
• The average untreated life expectancy is 5 years.

a. Use the Summation Method to calculate QALYs for the treatment.

b. Use the Summation Method to calculate QALYs for no treatment (do nothing).

c. Calculate QALYs gained by treatment.