Cost utility analysis

Abstract

Cost-utility analysis (CUA) has become widely used, particularly in the United Kingdom, compared with other techniques within cost-effectiveness analysis. CUA uses metrics such as the quality-adjusted life year (QALY) to assess the effectiveness of an intervention compared with an alternative. The QALY accounts for mortality (life years) and morbidity (severity of a state) in a single metric; the quality adjustment is based on stated preferences (also referred to as utility weights) that can be obtained from patients or the general public using preference elicitation techniques. For trial-based evaluations, preference-based measures have been developed to assess effectiveness and to elicit QALYs. Once the costs and QALYs for a study have been established, incremental cost-effectiveness ratios (ICERs) can be used as part of a decision rule whereby an ICER threshold (or league table) is set to inform decision makers about the potential comparative cost-effectiveness of an intervention. Within this chapter, extra-welfarism as the conceptual basis for CUA and reasons for the use of stated preference to represent utility weights are described. Preferencebased outcome measures and how they are used as part of cost-per-QALY analysis are also described; disability-adjusted life years are also considered. How ICERs, thresholds, and league tables can be used to inform decision-making is also introduced. Throughout this chapter, examples within the context of mental health are used. A final section is dedicated to specific implications of using CUA for evaluating mental health interventions and aspects to consider as CUA evolves.