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. Moreover, 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 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. Although ethical issues are discussed in greater detail in Chapter 6, a few ethical concerns should be mentioned here in the context of cost-effectiveness analyses. Some of these 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 for 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 achieved by averting a very small number of deaths. Some question the appropriateness of using such trade-offs. (See Chapter 6 for additional discussion.)
Whether these quality-adjusted years of life should be counted equally across all ages is a separate concern. The committee specifically chose not to follow the practice of some analysts who have assigned a greater value to the economically productive adult years than to years at younger or older ages (Murray and Lopez, 1996). The committee’s principal analysis follows the standard practice for QALY-based analysis of assuming that a QALY, once calculated, is not directly affected by age. The structure of the model, however, would permit others to perform analyses that incorporate age- or condition-specific weighting of QALYs.
Not addressed by the model are issues of equity in the allocation of resources. Some might argue that the needs of specific populations such as those defined by race, ethnicity, socioeconomic status, or health status should be given a higher priority than would be suggested by a strict ranking of cost-effectiveness ratios. The responsibility for judging what constitutes an equitable allocation should lie with accountable policymakers.
The analysis reflects several decisions by the committee regarding the approach to be used. These decisions resulted in the adoption of a societal per