A New and More Robust Test of QALYs
Previous empirical tests of quality-adjusted life-years (QALYs), the most widely used outcome measure in economic evaluations of health care, generally yielded negative results. These tests were, however, for the most part based on expected utility, which is now widely acknowledged to be descriptively inaccurate. The observed violations might, therefore, have been caused by violations of expected utility. We performed a new test of QALYs, which is valid under expected utility and under the two most influential non-expected utility theories, rank-dependent utility and prospect theory, and found considerable support for the QALY model. Our findings suggest that QALYs may be valid if nonexpected utility formulas are used to compute health state utilities.