Rosalind Rabin, Frank de Charro, Agota Szende 1.1 Purpose of this booklet Governments and healthcare funders worldwide are making increasing use of economic evaluation to inform priority setting in health care. For various reasons, cost benefit analysis is usually rejected in favour of cost-effectiveness or cost-utility analyses, often involving the estimation of the incremental cost per Quality Adjusted Life Year (QALY) gained (Drummond et al, 2005). The estimation of QALYs gained requires valuations for all relevant health states on a scale anchored at 1 = Full health and 0 = Dead. The...