Making Good Decisions: Examining the Cost-Effectiveness and Optimal Timing of the Herpes Zoster Vaccine.

Abstract

Herpes zoster (shingles) is a disease that approximately 90% of the US population is at risk of developing. This disease causes intense pain which can affect quality of life and has a substantial economic burden. A vaccine is available to prevent the disease, and currently this is the best tool available for combating this disease. However, the vaccine does not have lifelong durability, and it has less efficacy in older people. Therefore, it is important to make good decisions on how and when to administer this vaccine so that we maximize both its benefit and our available resources. This dissertation uses the techniques of cost-effectiveness analysis, stochastic dynamic optimization, and value of information analysis to focus on decision making about how to best use the vaccine. First, cost-effectiveness was completed to show the value at different ages of vaccination. Stochastic dynamic optimization built upon the cost-effectiveness models to determine the optimal time to administer the vaccine. Finally, value of information analysis examined how the optimal policy may change if perfect information were available on some of the key uncertain parameters. Results indicate that age 67 is the most cost-effective age to vaccinate men and women. The optimal policy results from the stochastic dynamic program suggest it would be best to start vaccinating men and women at age 66 and to stop at 74 (men) or 77 (women). Results show that there is some value to determining the additional information on key uncertain model parameters. However, the value we can gain is unlikely to be worth the investment in the additional research that would be required. Overall this dissertation shows that the recommended policies in the US of vaccination at 60 and older could be sub-optimal. Given the results of the models it may be more optimal to change the recommendation to 65 and older so that the benefits of the vaccine are conferred at the best times.