OBJECTIVES: A public health intervention in Scotland in a form of a natural experiment was used to develop a broader economic evaluative space that combines a traditional cost-utility analysis (CUA) with a discrete-choice experiment (DCE). The intervention involved regenerating and improving woodlands through physical changes and promoting the woodlands as safe in order to increase access to woodlands in areas of high social deprivation closely linked to poor health. Increased access to woodlands could in turn increase physical activity and provide benefits to individuals which are broader including health and non-health that do not fit in a conventional quality-adjusted life year (QALY) framework.

METHODS: A CUA valued the health outcomes in terms of QALYs. The EQ-5D-5L instrument was administered before and after the intervention to the intervention group (n=3,165) and control group (n=3,152). A DCE generated relative societal willingness to pay (WTP) values from the general population (n=510) for the improvements in the attributes resulting from the intervention. A net monetary benefit (NMB) framework was then used to monetize the QALYs from the CUA that allowed combining the WTP results from the DCE on the same monetary scale, effectively deriving a cost-benefit analysis (CBA). The time horizon for the evaluation was 2 years.

RESULTS: The cost per QALY was £513 for the health outcomes. The total WTP for the incremental improvements in the attributes of the intervention for non-health outcomes was £6.89. The intervention was cost-beneficial in terms of both incremental effect of QALYs for health outcomes and incremental improvements in the attributes for non-health outcomes with a NMB of £475 at WTP threshold of £20,000.

CONCLUSIONS: The conventional QALY framework and WTP results from a DCE can be combined on a single monetary scale using the NMB framework to offer a broader economic evaluative space particularly suitable for a public health intervention.