Abstract
It has been demonstrated conclusively that value and utility preference scores have only ordinal properties. This means, as has been pointed out on numerous occasions, that the quality adjusted life year (QALY) is a mathematically impossible construct. The implications are profound: Some 30 years of health technology assessment is called into question due to a failure to recognize the well-documented limitations imposed by the axioms of fundamental measurement. The purpose of this commentary is provide a critical examination of this practice in recommendations for atopic dermatitis.