Utility theory and quality of life assessment in the economic evaluation of health care programmes

In this paper, the issue of quality of life measurement in economic evaluat ion of health care is presented and discussed. In the first section of the article, methods for the economic evaluation are briefly presented within t he theoretical framework of expected utility theory. In the second section, a number of situations are pointed out where health-related quality of lif e is an important outcome or both morbidity and mortality are affected. The se types of situation give the rationale for the development of a new metho d, called cost-utility analysis. It enables a broad range of relevant outco mes to be combined into a single composite summary outcome like Quality Adj usted Life Years (QALYs) gained. The advantage of QALY as a measure of heal th outcome is that is simultaneously capture gains from reduced morbidity ( quality gains) and reduced mortality (quantity gains) and integrate them in a single indicator. The combination is based on the relative desirability of the different outcomes from the individual' points of view, In the conve ntionnal approach to QALYs, the quality adjustment weight for each health s tate is multiplied by the time in the state and then summed to calculate th e number of quality adjusted life-years. In a particular study, cost-utilit y ratios of concurrent options will be compared and an incremental analysis of costs and consequences of the alternatives will be performed. In the fi rst years of utilisation, cost-utility analysis were conducted for specific interventions, especially innovating ones. More recently, some economists advocate that cost-utility ratios could be used to inform decisions about t he allocation of health care resources between alternatives programs and to aid for determining priorities of the health care system. For such purpose s, health care interventions should be compared and ranked in terms of thei r relative cost per QALY gained (league table). Some economists argued that adoption and utilization of new technologies should be classified into dif ferent grades of recommendation based on their incremental cost per QALY. A ll these proposals have been strongly criticised. Methodological objections have been addressed. The consistency of the cost per QALY approach with we lfare economic theory has also been questioned. It has been proved that QAL Ys can be utilities if very restrictive conditions are respected, which is very uncommon in practice. These criticisms are summarised in the last sect ion of the paper. In conclusion, the cost-utility is an approach to be used with caution. Nevertheless, its utilisation can be necessary to inform dec isions as it gives the unique opportunity to take into account individual p references when valuing outcomes of health care interventions.