Once the morbidity scenarios were developed, the committee reviewed each health state and assigned a level in each of the seven attributes of the HUI Mark II. Box 4–2 shows the committee’s attribute scoring for one health state (ectopic pregnancy). The quality-adjustment weight for the health state was obtained by combining the scores for each attribute using the multiplicative HUI Mark II formula. Box 4–4 shows examples of the quality adjustment weights obtained for several health states.

To measure the health benefits associated with an intervention such as the use of a new vaccine, it is necessary to compare health status with and without the intervention. The quality-adjustment weights for each condition’s morbidity scenarios (described above) are used to calculate QALYs lived without the intervention. Quality-adjustment weights reflecting the average health status of the population are used to calculate QALYs lived with the intervention. To measure the impact of mortality and lifetime impairment, life-expectancy was “quality adjusted” for the average health status of the population and discounted to its present value. For example, the life expectancy at birth is 75.5 years in the 1993 life tables used in the committee’s analysis. The discounted quality-adjusted present value of that life expectancy is 26.8 years. For a person 50 years old