Maximizing Health or Sufficient Capability in Economic Evaluation? A Methodological Experiment of Treatment for Drug Addiction

Abstract

Conventional practice within the United Kingdom and beyond is to conduct economic evaluations with 'health' as evaluative space and 'health maximisation' as the decision making rule. However, there is increasing recognition that this evaluative framework may not always be appropriate, and this is particularly the case within public health and social care contexts. This paper presents a methodological case study designed to explore the impact of changing the evaluative space within an economic evaluation from health to capability wellbeing and the decision making rule from health maximisation to the maximisation of sufficient capability. Capability wellbeing is an evaluative space grounded on Amartya Sen's capability approach and assesses wellbeing based on individuals' ability to do and be the things they value in life. Sufficient capability is an egalitarian approach to decision making that aims to ensure everyone in society achieves a normatively sufficient level of capability wellbeing. The case study is treatment for drug addiction and the cost-effectiveness of two psychological interventions relative to usual care is assessed using data from a pilot trial. Analyses are undertaken from a health care and a government perspective. For the purpose of the study, Quality-Adjusted Life-Years measured using the EQ-5D-5L, Years of Full Capability equivalent and Years of Sufficient Capability equivalent, both measured using the ICECAP-A, are estimated. The study concludes that different evaluative spaces and decision making rules have the potential to offer opposing treatment recommendations.The implications for policy makers are discussed.

Using deliberative methods to establish a sufficient state of capability well-being for use in decision-making in the contexts of public health and social care

“…Existing empirical evidence indicates that changes in the evaluative space (capability well-being rather than health) (Mitchell, Al-Janabi et al 2015) and changes in the decision rule (sufficiency rather than maximisation) can change treatment decisions (Goranitis, J et al 2017), but so far there is a very small body of evidence available.…”

Are Quality-Adjusted Life Years a Good Proxy Measure of Individual Capabilities?

“…Differences exist, not only in measurement, but also in decision rules and valuation where the extra-welfarism commonly applied remains inherently welfarist in practice [ 23 , 61 ]. Progress has been made in developing a capability approach alternative to standard practice in terms of measures of capability [ 16 , 62 ], decision rules by moving towards a sufficient capability objective [ 63 , 64 ], and valuation with best–worst scaling DCE offering a mechanism for estimating the relative importance of different capability states [ 30 ]. Further research is still required, particularly on how a unit of capability gain, however defined, is monetarily valued before a fully workable alternative to the conventional QALY approach can be provided to decision makers.…”

Predicting health-related quality of life (EQ-5D-5 L) and capability wellbeing (ICECAP-A) in the context of opiate dependence using routine clinical outcome measures: CORE-OM, LDQ and TOP

“…The application of the ICECAP-A could have the ability to capture mental health related quality of life outside the utility framework. In relation to mental health, recovery entails a variety of things, drug control, physical and mental health [ 45 ]. Mapping from a condition-specific measure to a traditional generic preference-based measure could miss out these key drivers within the recovery process.…”