must be compared and related to a variety of costs. It cannot, however, address all of the qualitative judgments that shape policy decisions.
The cost-effectiveness approach also provides a framework within which the components of the analysis can be specified in detail and evaluated by those who use the results. This is particularly helpful for the committee’s analysis, which, of necessity, rests on many estimates and assumptions about the characteristics of future vaccines and their likely impact on health and costs. The detailed specification of the components of the model also facilitates sensitivity analyses for the testing of alternative estimates and assumptions, either for individual patients or for all patients.
The cost-effectiveness analysis used by the committee can provide an estimate of the cost of achieving the anticipated health benefit for each of the vaccines studied, but it cannot determine whether that health benefit is worth the cost. That decision is a value judgment and should reflect consideration of many factors that are not included in the analysis. For example, the committee’s analysis does not consider what resources will or should be available for vaccine development or how many vaccine candidates should be given priority for development. Furthermore, the analysis does not address the allocation of resources between vaccine development and the development and use of other forms of prevention or treatment. Although priority setting and resource allocation can be informed by economic analyses, they require value judgments that cannot be captured by a cost-effectiveness model.
It is also important to note that the results of the analysis depend on the accuracy and appropriateness of the data and the assumptions that are used, a point of particular relevance to the committee’s work. Assumptions were necessary both to compensate for the limitations of the available data on current disease incidence and costs of care and to simplify some analytic tasks. Furthermore, the vaccines that are the focus of the study are still in development, making it necessary to rely on expert judgment for values such as costs of vaccine development and time until a vaccine will be licensed for use. Those who use the committee’s analysis or similar types of studies should keep in mind that although the results are quantified they should not be treated as precise measures.
Cost-effectiveness analysis raises several ethical issues, especially in the context of priority setting. Some ethical concerns are a function of value judgments incorporated into the model, and others are related to issues that are not addressed. For example, within the model, all QALYs are considered equal without regard to the nature of the health benefit that they measure. Thus, the number of QALYs gained through many people receiving a small health benefit as a result of a reduction of a minor form of illness can be the same as the number of QALYs gained by averting a very small number of deaths.