Adaptation and scale of reference bias in self-assessments of quality of life.

Adaptation behaviour and different scales of reference can bias self-assessments of well-being by individuals. In this paper, we analyse the impact of these biases on a subjective measure of the quality of health and on the QALY weights derived from this health measure. It is found that the scale of reference of the subjective health measure changes with age. Accounting for adaptation and scale of reference bias lowers most of the QALY weights for health problems and disabilities.