ReviewMethods for assessing the cost-effectiveness of public health interventions: Key challenges and recommendations
Introduction
Within the UK and elsewhere, increasing attention has been given to the evaluation of public health interventions. The Wanless Reports highlighted the need to consider the cost-effectiveness of public health interventions [1], [2]. Since 2005, the National Institute for Health and Clinical Excellence (NICE) has produced guidance in the public health field for the UK National Health Service. The generation of good quality evidence on cost-effectiveness is essential if those commissioning services are to make informed decisions.
Methods for the economic evaluation of healthcare interventions have existed for several years, but these have mainly been applied to more narrowly defined ‘clinical’ interventions, such as drugs, devices and medical procedures. In addition, the methods for the evaluation of screening and immunisation programmes are fairly well developed. Although there are a number of features of these programmes which require particular attention, for example, whether or not to evaluate vaccines using a static or a dynamic approach to model the impact of the spread of infection, the methods are established and are similar to those used for clinical interventions [3]. By comparison, economic evaluations of other, broader, public health interventions are scarce and the methods uncertain [4].
Initially, five reviews that explored the economics of public health were consulted [1], [2], [5], [6], [7]. McDaid and Needle [5] undertook a systematic review of the empirical approaches used to assess the cost-effectiveness of a broad range of public health interventions. West et al. [6] undertook a rapid review of a selected range of public health interventions and identified key lessons, barriers and gaps within the evidence-base. Two reports by Wanless [1], [2] examined how resources might be best used to secure the health of the whole population. And, finally, an Australian Report [7] examined the returns on investment in public health in a selected range of public health interventions. From these, key insights into the main methodological challenges for the economic evaluation of public health interventions were obtained.
Public health interventions generate very broad costs and benefits and are often directed at populations or communities rather than specific individuals. Therefore, it is relatively difficult to undertake randomised controlled trials (RCTs). Secondly, the broad nature of the costs and benefits suggests that an intersectoral approach is required in order to identify them. Thirdly, given their broad nature, standard approaches to valuing health gain (e.g. in quality-adjusted life-years, QALYs) may be inadequate. Finally, a particular feature of many of these interventions is a concern with health inequalities. Standard economic evaluation methods focus on efficiency (i.e. the maximization of health gain) rather than on equity (i.e. the distribution of health gains). Accordingly, the evaluation of public health interventions may need to pay more attention to equity considerations.
Section snippets
Methods
The four methodological challenges for assessing the cost-effectiveness of public health interventions were identified and are described in more detail below. Following this, the methods used for the review of the empirical literature are described. The empirical review focused on how the methodological challenges had been addressed in practice.
Results
1264 NHS EED abstracts were identified for possible inclusion in the review of the empirical literature. After screening the abstracts, 154 unique abstracts were retained for review (Table 1). A full list of the studies is available in the main project report, which is available via www.york.ac.uk/phrc.
The studies related to the following years: 27 in the year 2000, 37 in 2001, 34 in 2002, 29 in 2003, 24 in the 2004 and 3 in 2005. The low number of studies for 2005 reflects a time lag in
Discussion
The review of empirical studies shows that economic evaluation has been applied in a wide range of public health areas. However, overall there were few insights gained from the empirical review as to how to address the methodological challenges. Nevertheless, expert opinion suggested a number of ways forward as discussed below.
Conclusions
The economic evaluation of public health interventions presents four main methodological challenges. The existing empirical literature is very disappointing, offering few insights on how to respond to these challenges. This severely limits the usefulness of economic evaluation in this field. Despite the lack of insights provided by existing studies, consideration of the theoretical literature and expert opinion suggests a number of ways forward. Much of what is suggested here has not yet been
Acknowledgments
This report was undertaken as part of the Public Health Research Consortium (PHRC). The Consortium is funded by the Department of Health Policy Research Programme. Thanks are due to the attendees at a workshop, held in York on August 4, 2006, for their helpful comments and suggestions namely, Andrew Briggs, Janine Hale, Jacqueline Mallender, Christine McGuire, Miranda Mugford, Bash Naidoo, Mark Petticrew and Phil Shackley (unable to attend). Further useful comments and suggestions were made by
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