On future non-medical costs in economic evaluations

Economic evaluation in health care is still an evolving discipline. One of the current controversies in cost-effectiveness analysis regards the inclusion or exclusion of future non-medical costs (i.e. consumption net of production) due to increased survival. This paper examines the implications of a symmetry rule stating that there should be consistency between costs included in the numerator and utility aspects included in the denominator. While the observation that no quality-adjusted life year (QALY) instruments explicitly include consumption and leisure seems to give support to the notion that future non-medical costs should be excluded when QALYs are used as the outcome measure, a better understanding of what respondents actually consider when reporting QALY weights is required. However, the more fundamental question is whether QALYs can be interpreted as utilities. Or more precisely, what are the assumptions needed for a general utility model also including consumption and leisure to be consistent with QALYs? Once those assumptions are identified, they need to be experimentally tested to see whether they are at least approximately valid. Until we have answers to these areas for future research, it seems premature to include future non-medical costs.