MULTI-CRITERIA DECISION ANALYSIS: USEFUL, BUT NOT A SUITABLE REPLACEMENT FOR COST-EFFECTIVENESS ANALYSIS

Purpose: To demonstrate that multi-criteria decision-analysis (MCDA) will not lead to the optimisation of desirable attributes when allocating scarce healthcare resources and so is not a suitable replacement for cost-effectiveness analysis.

Method(s): We use a simple model to simulate a set of hypothetical interventions, each with a given level of costs, health effects (which may be quantified in quality-adjusted life-years [QALYs] or some other measure) and a second beneficial attribute. A budget constraint is assumed such that not all available interventions can be funded. We identify the set of interventions that forms a production possibilities frontier (PPF) of treatment combinations that maximises combinations of QALYs and the second attribute for the budget constraint. This frontier determines the optimal set of interventions for the constrained budget depending on the rate the decision maker chooses to trade-off QALYs against the second attribute. We then apply an MCDA approach that attaches weights to the level of the second attribute and the net health benefit of each intervention according to a range of cost-effectiveness threshold values. For each set of weights and thresholds we identify the interventions that maximise the MCDA score. These interventions are described as the MCDA-preferred interventions. We compare the MCDA-preferred interventions to the PPF. The model is complemented with a brief survey of the literature on the methodology and application of MCDA in healthcare resource allocations.

Result(s): We find that the MCDA approach generally does not select interventions that lie on the PPF. Accordingly, the MCDA approach will not always maximise desirable outcomes.

Conclusion(s): There is growing interest in using MCDA to guide healthcare resource allocation. Although the methods for MCDA as a guide to healthcare resource allocation have yet to be fully described, it has been suggested that MCDA should replace cost-effectiveness analysis. The results presented here show that MCDA can result in sub-optimal resource allocation. This does not necessarily imply that MDCA is not useful. Indeed, it can be helpful in clarifying decision makers' objectives. Nevertheless, advocates of MCDA should carefully consider its limitations before recommending its use. Further exploration of MCDA's limitations will inform how attributes other than costs and QALYs can be appropriately integrated in healthcare resource allocation.