A broader economic evaluative space for public health interventions: an integrated approach

RA Public aspects of medicine

Botha, Willings ; National Institute for Health Research (NIHR) ; Briggs, Andrew

University:University of Glasgow

Department:Institute of Health and Wellbeing

关键词: public health interventions, cost-benefit analysis, integrated approach, stated preference discrete choice experiment, willingness to pay, difference-in-differences.;   

Others  :  http://theses.gla.ac.uk/8488/1/2017BothaPhD.pdf

来源: University of Glasgow

【 摘 要 】

Introduction: There is an increasing need for economic evaluation of public health interventions to ensure efficient allocation of resources. Outcomes of such interventions often consists of health and non-health and do not fit in the conventional economic evaluation of quality-adjusted life year (QALY) framework. A cost-benefit analysis (CBA) could be appropriate but has concerns of assigning monetary values to health outcomes. Questions remain on how to consider the broad outcomes of a public health intervention in an economic evaluation.Objective: This thesis aimed to develop an integrated approach for an economic evaluation of a public health intervention that combines the standard cost-utility analysis (CUA) for health outcomes with the stated preference discrete choice experiment (SPDCE) approach for non-health outcomes on a single monetary metric. Methods: A natural experiment of the Woods In and Around Towns (WIAT) study in Scotland was used for empirical analysis. Costs were assessed using a top-down approach based on resources used. A difference-in-differences (DiD) approach was used to establish the impact. A CUA valued the health outcomes in terms of QALYs while a previously developed conceptual model of the WIAT was used to identify the SPDCE attributes and levels for the non-health outcomes. The WIAT study questionnaire was mapped to the SPDCE which generated relative willingness to pay (WTP) values from a general Scottish population. The WTP estimates were applied to the changes or improvements in the attributes and levels resulting from the intervention. A net monetary benefit (NMB) framework was then used to combine the CUA with the SPDCE on the same monetary scale, effectively deriving a CBA.Results: The WIAT interventions were of low cost despite the base case DiD analysis showing a statistically insignificant effect for interventions. The incremental cost-effective ratios (ICERs) for the interventions revealed that they were cost-effective. The probabilistic sensitivity analysis (PSA) showed that the physical intervention was 73% likely to be cost-effective at WTP of £20,000 and £30,000. The combined physical and social interventions had 74% and 75% likelihood of being cost-effective at WTP of £20,00 and £30,000, respectively. There was a great deal of uncertainty around QALY results. Overall, the integrated approach revealed that the WIAT interventions were cost-beneficial in terms of both health and non-health outcomes. Conclusion: This thesis has proposed and demonstrated the integrated approach that combines the conventional QALY framework with the SPDCE on a single monetary scale, hence a broader economic evaluative space particularly suitable for an economic evaluation of a public health intervention.