15.2.1  Formulating an economics question

Following a decision to include coverage of economic aspects of interventions in a Cochrane review, the first stage of research is to formulate one or more questions, or objectives, that the economics component of the review will seek to address. Each economics question or objective will determine methodological decisions in subsequent stages of the critical review of health economics studies.

 

Formulating an economic question requires close consideration of the role and relevance of economic issues to the specific overall review topic. The preliminary questions below are intended to provide useful starting points to help authors and editors conceptualize the role and relevance of economic issues.

 

In considering these preliminary questions, it is important to take the following key issues into account:

 

Clinical event pathways can provide a further useful tool to help conceptualize the role and relevance of economic issues to a specific review topic. A clinical event pathway provides a systematic, explicit method of representing different health and social care processes and outcomes. The method involves describing the main pathways of events that have distinct resource implications or outcome values associated with them, from the point of introduction of the interventions, through subsequent changes in management of participants, to final outcomes (see also Chapter 2 of Donaldson (Donaldson 2002)). Figure 15.2.a shows an example clinical event pathway for the clinical event ‘stroke’. In developing a clinical event pathway, it is again important to consider the key issues of magnitude, time horizon and analytic viewpoint.

 

Once the role and relevance of economic issues has been considered carefully, one or more economic questions, or objectives, can be formulated. Review authors should avoid asking economic questions of the form ‘What is the cost-effectiveness of intervention X (compared with Y or Z)?’, since a critical review of health economics studies is unlikely to provide a credible answer to this type of question that is applicable across settings. Economic questions, or objectives, should be stated explicitly in the Objectives section of the protocol for a review, alongside other research questions and objectives.

 

Considerations of the role and relevance of economic issues can also be used to inform a commentary on economic aspects of interventions, to be included in the Background section of the review.

 

An ‘economics commentary’ can be included whether or not the authors intend to incorporate a critical review of health economics studies. This is useful to help set the interventions being studied in an economics context by highlighting their potential economic consequences for consideration by end-users of the review. The ‘economics commentary’ may highlight the economic burden of the illness or medical condition being addressed by interventions, the types of resources required to implement and sustain interventions (resource inputs), the potential impacts of interventions on the subsequent, downstream use of resources (resource consequences) and issues of cost-effectiveness. The commentary should be supported by appropriate references to, and critical comment on, relevant literature wherever possible. Box 15.2.a shows some examples of this type of commentary, extracted from Background sections of current Cochrane reviews.