QALYs, Person Trade-Offs, and the Pareto Principle.

A considerable literature seems to argue the use of person trade-offs to estimate the quality-adjustment factor in Quality-Adjusted Life Years (QALY) models. A similar practise is followed by the WHO to estimate the disability weights used in calculation of Disability-Adjusted Life Years (DALY) for assessment of region- and disease-specific burden of disease. In this note we show that QALY (and DALY) models based on person trade-off scores generally violate the Pareto principle.