Costing interventions in primary care.

Against a background of increasing demands on limited resources, studies that relate benefits of health interventions to the resources they consume will be an important part of any decision-making process in primary care, and an accurate assessment of costs will be an important part of any economic evaluation. Although there is no such thing as a gold standard cost estimate, there are a number of basic costing concepts that underlie any costing study. How costs are derived and combined will depend on the assumptions that have been made in their derivation. It is important to be clear what assumptions have been made and why in order to maintain consistency across comparative studies and prevent inappropriate conclusions being drawn. This paper outlines some costing concepts and principles to enable primary care practitioners and researchers to have a basic understanding of costing exercises and their pitfalls.