[The QALY approach - potentials and limits].

The concept of quality-adjusted life expectancy ("quality-adjusted life years", QALY) is a type of cost-benefit analysis for health economic evaluation of treatment options. The two parameters quality of life and life expectancy are thereby combined into a single value - the QALY - which can shed light on the cost of therapy per additional quality-adjusted year of life. The concept is, however, widely used in ethical discussions of the adequacy of the generalizations on which this approach is based. Using the simulation of an American research team on treatment forms for prostate cancer, the QALY concept is explained, followed by the presentation of ethical criticisms.