15.6.4  Developing an economic model

Cochrane reviews can contribute key components of the evidence required to develop a subsequent or parallel full economic evaluation, including use of a decision-analysis approach for pooling or modelling the available evidence on intervention costs and effects (see also Sections 15.1.2 and 15.1.3). This approach usually involves estimation of the point estimate, and description of the joint distribution, of incremental costs and effects resulting from an intervention (in terms of cost-effectiveness, cost-utility or cost-benefit), compared with a relevant alternative, in a defined population and setting, and with included costs and outcomes agreed to be relevant from a specific, stated analytic viewpoint (e.g. patient, healthcare provider or third-party payer, healthcare system, society).


Economic modelling methods are not covered in detail here, as their routine use as part of the Cochrane review process is not recommended. However, authors of Cochrane reviews wishing to pursue the ‘in-depth’ economics of interventions are encouraged to collaborate with researchers with expertise in developing economic models. It may sometimes be possible to develop a general structure for an economic model as part of a Cochrane review, where the basic model inputs and outputs are similar across different settings, but where some (or even all) of the data required to populate the model are specific to a local setting.


Also, notwithstanding issues already discussed regarding the generalizability and transferability of the results of economic evaluations across jurisdictions and settings (see Section 15.6.3), it cannot be ruled out that it may sometimes be considered worthwhile (although time, resource and expertise intensive) to develop one or more economic models for publication in a Cochrane review. For example, one motivation to develop an economic model as part of a Cochrane review may be an intention to use the review to inform directly the design of future research that will incorporate an economic evaluation component. In these circumstances, developing a model can help to clarify the structural assumptions and parameters that need to be considered in an economic evaluation, and the data that will need to be collected during the research. If this type of approach is pursued in a Cochrane review, it needs to be made clear that each example economic model aims to provide an illustrative assessment of the cost-effectiveness of the interventions being compared, in an example jurisdiction and at a given point in time.


Economic modellers are also encouraged to consider utilizing the evidence contained in Cochrane reviews to inform the development of economic models. Efforts to incorporate economics evidence into Cochrane reviews using the methods outlined in this chapter aim in part to increase the relevance and applicability of Cochrane reviews for use in subsequent, or parallel, full economic evaluation modelling exercises.