The role of models within economic analysis: focus on type 2 diabetes mellitus.

Economic analysis of healthcare interventions is increasingly reliant on decision models to estimate the long-term costs and benefits of new therapies. Models permit analysts to take short-term clinical data to forecast long-term costs and benefits. Models should follow certain basic principles and can be appraised in terms of three broad characteristics: clinical relevance, transparency and analytical ability. The purpose of this paper is to explore the role of modelling in the economic analysis of interventions for type 2 diabetes mellitus. A review of existing models for diabetes identified five complex disease models appropriate for economic analysis. These models were broadly similar in structure and in source of input parameters. However, models did vary according to the coverage of relevant disease complications and the complexity of analysis possible. Models could be enhanced by improving their transparency and by using data relevant to type 2 diabetes. In addition, enhancing clinical knowledge through the provision of long-term data on effectiveness may reduce concern relating to the appropriateness of the assumptions currently required within models. The value of such further information must be weighed against the costs of its acquisition.