BROADENING ECONOMIC EVALUATION - A CASE STUDY OF DEMENTIA

Purpose: The practice of health technology assessment (HTA) has traditionally been dominated by cost effectiveness analyses (CEA) using quality adjusted life years (QALYs) as the measure of benefit. However, a review of decisions by NICE and other HTA agencies revealed that other criteria are being used during evaluuation of medical technologies. Does the implicit use of these other criteria than cost-effectiveness benefit the legitimacy, consistency and transparency of the HTA decisions? Is there is a need for a more explicit and formal approach. In other words, how should these other criteria be considered in HTA decisions?

Method: We present two alternative methodological  frameworks to undertake economic evaluation using a wider perspective. Dementia will be used as a case study, as it has a big impact on health, social care and informal caregivers. We will present a whole system micro simulation model for dementia to include costs and consequences on all the sectors. Then, we present the data gathered on impact of dementia interventions from literature and analysis of routine data available to us. The impact of different dementia interventions are estimated using the data on costs and outcomes input into the model. The model will then be operationalised using two economic frameworks: a) extending a cost-per-QALY approach and b) cost consequence analysis (CCA) with Multi-Criteria Decision Analysis (MCDA) approach. 

Result: Extending the cost-per-QALY approach to incorporate other criteria requires recalculation of the cost effectiveness threshold - this is because if different ‘benefit function' than QALYs is used then the threshold needs to be recalculated taking into account the displaced 'benefit function' i.e adjusted cost per ‘benefit function threshold. However, this can lead to consistency as all the things are explicitly included in a CEA framework.  MCDA can also be used to guide decision makers in understanding the trade-offs between values that may be conflicting and can be done a case-by-case basis. Many different tools and techniques are available under the general heading of MCDA ranging from fully quantitative MCDA models to more deliberative MCDA approaches.

Conclusion: In certain HTA problems, there may be a need for incorporating other important considerations than just QALYs. There a number of frameworks available for broadening economic evaluation and the choice between different methods may depend on the need for consistency, scale of the problem and the stakeholders.