Methods to assess the comparative value of investing in different health interventions are well established, if imperfect.7
These methods—cost-effectiveness analysis and cost–benefit analysis—have been commonly used to assess malaria control, and extensive published work about their effective execution exists.8
Elimination, however, has several unique attributes that warrant adaptations of standard methods to generate results most relevant to policy.
There are several overarching principles that are central to any economic analysis of elimination. First, and most importantly, is the definition of the alternative to elimination. WHO recommends a null state of disease without intervention as the alternative.9
In practice, most health-economic analyses use a loosely defined status quo, which varies substantially between countries. Such is the case for much of the microeconomic and macroeconomic analyses of malaria interventions so far.7
A null-state alternative can provide important information about the total value of a malaria programme. This information is particularly useful for policy makers to understand the benefits of continued investment in malaria, even when the disease is greatly reduced or absent. However, the main choice facing countries is between elimination and controlled low-endemic malaria, not a retraction of existing interventions or acceptance of partial, suboptimum control (ie, often the status quo).10
As such, the most policy-relevant alternative for economic analysis of elimination is controlled low-endemic malaria. Although seemingly intuitive, this approach is not always used in the existing analysis of elimination and eradication. For example, many of the cost–benefit analyses of efforts to eradicate other infectious diseases have used a complete absence of control as the alternative to eradication.11–13
A second imperative of elimination analysis is the inclusion of postelimination costs. During the GMEP, the expectation was that malaria-related expenditure would stop after elimination.14
However, most successful countries needed to continually invest in surveillance and other interventions.15
Thus, the inclusion of a robust estimate of postelimination interventions in all costing analyses, taking into consideration the potential sharing of costs with other disease programmes, is important.
Lastly, the supranational implications of elimination should be considered. As a country approaches and reaches elimination, its neighbours—and many other countries—benefit from reduced importation of malaria and the corresponding reduction in the risk of outbreaks. These spillover benefits should be incorporated into a complete economic evaluation of elimination.
Cost-effectiveness analysis, which calculates the amount of funding an intervention needs to prevent loss of a standard unit of disease burden, is the most commonly used approach to compare the economic attractiveness of health programmes.8
Both cost-effectiveness analysis and the related cost-minimisation analysis have important parts to play within an elimination context by identifying the optimum level of intervention needed to achieve controlled low-endemic malaria and elimination and prevent reintroduction once malaria-free status is achieved. These analyses are essential for robust economic assessments of elimination and are valuable programme planning interventions.
Cost-effectiveness analysis, however, is likely to be incapable of adequately informing the ultimate choice between elimination and controlled low-endemic malaria. Elimination has been justified on the basis of more than health outcomes—the threats of insecticide resistance and the instability of international malaria funding were the central impetus for the GMEP16
—and recent arguments for elimination have focused on the effect on economic growth and international externalities.17,18
Moreover, policy makers often place substantial value on outcomes beyond efficiency in prioritisation of the allocation of health resources;19,20
thus cost–benefit analysis, which enables broader benefits to be translated into a common monetary metric, is a more effective means to inform strategic decisions regarding potential elimination strategies.
Considerable, if arguably insufficient, analysis has been done to investigate the costs and benefits of malaria control, and has shown it to be among the most attractive applications of global social investment.7,21,22
However, no comprehensive cost–benefit analysis has been completed for malaria elimination using an alternative of controlled low-endemic malaria.4
Analyses of programmes to eliminate or eradicate other infectious diseases have consistently reported that benefits outweigh costs, but these analyses cannot be directly applied to malaria.23
Effective cost–benefit analysis of elimination will need alternative approaches to assess benefits. Cost–benefit analysis usually focuses on benefits that are closely linked to the health effects of the programme, including reduced public and private expenditure (direct) and increased productivity and educational attainment (indirect).7
These benefits will always be modest for elimination—the main effect on educational attainment, for example, will result from the achievements of the baseline control programme. Elimination might, however, increase the equity of these benefits. The poorest and most vulnerable members of a society are typically the last to benefit from public services such as malaria control and will thus be the primary beneficiaries of an elimination campaign.24
As such, for societies that prioritise distribution in addition to efficiency of health outcomes, equity should be appropriately incorporated into cost–benefit analyses of elimination.25–27
The economic attractiveness of elimination will often depend on two additional classes of benefits: financial and threshold. Financial benefits might be realised if recurring costs fall sufficiently after elimination so that the cumulative cost of the programme is lower than that of controlled low-endemic malaria over the medium-to-long term. In this event, the elimination programme will pay for itself and its benefits will always exceed its costs. Accordingly, this financial analysis is a central component of the economic evaluation of elimination, although not the primary metric, as Mills and colleagues4
Many of the supposed benefits of elimination are only realised once the absolute threshold of malaria-free status is achieved.18
A common argument is that elimination will generate substantial additional economic activity by creation of an environment conducive to direct foreign investment and tourism, among other advantages. Since there is only modest risk of malaria at the baseline state, this argument relies on the assumption that companies and individuals will perceive a disproportionate difference between controlled low-endemic malaria and elimination. Maartens and colleagues28
reported that tourists' perceptions of risk were highly unresponsive to actual changes in malaria transmission in an area of South Africa. This finding is consistent with published work on divergences between actual and perceived risk of infectious disease and their effect on economic behaviour;29,30
however, the existence and magnitude of this effect for malaria elimination has never been studied.
Several other costs and benefits should ideally be included in a comprehensive cost–benefit analysis of elimination, but they are considerably more difficult to quantify. These factors include the potential increase in public confidence in government services and international recognition generated by successful elimination of a tenacious disease.10
Elimination could also strengthen components of the health system as occurred in the USA through the creation of the Centers for Disease Control and Prevention,31
although others contend that the GMEP undermined surveillance and other systems.32
Conversely, substantial political will, domestic and potentially international, will be needed to achieve elimination. Lines and colleagues1
suggest that the risk and consequences of failing to eliminate (eg, resurgence resulting from disillusionment with the programme) should be a prominent factor in elimination decisions and related analyses. However, this approach would affect the cost–benefit ratio of elimination only if the risks posed by elimination are greater than those of controlled low-endemic malaria; there is no evidence to suggest this would be the case.33
Overall, the decision whether or not to pursue elimination is best informed by a comprehensive cost–benefit analysis that compares the potential net benefits of elimination with those of continued controlled low-endemic malaria. Such an exercise should begin with cost-minimisation analysis—which is largely absent despite the volume of resources invested in malaria—to establish the optimum package of interventions with which to achieve both controlled low-endemic malaria and elimination. Ultimately, the economic attractiveness of elimination will rely on financial and threshold non-health benefits, including those yielded by other countries. Robust quantification of those benefits will be complex and time consuming, suggesting that other methods such as cost-effectiveness analysis should be used in the short term. However, in view of the shortcomings of those methods and the informal judgments that drive elimination-related decisions, even a partial application of this cost–benefit analysis framework could produce improvements in debate and decision making.34