The trade-off between severity of illness and treatment effect in cost-value analysis of health care.

Social appreciation of health care programs is a function of the severity of the patients' initial state as well as of treatment effect. Prioritising on the basis of cost-per-QALY misses the former point. The trade-off between severity and treatment effect can be expressed in terms of equivalence of numbers for different outcomes. The present study suggests that this trade-off can be modeled mathematically with reasonable accuracy. A table that expresses social equivalence numbers as a function of severity and treatment effect could be used together with guidelines for adjusting for age, duration and risk to estimate the social value of any outcome. In this valuation, saving a young person from dying to a life as healthy (= 1 SAVE) is suggested as the unit of measurement. Cost per SAVE may then be useful as a guiding criterion in prioritising.