British Medical Journal
28 May 2011 Volume 342, Issue 7808
http://www.bmj.com/content/current

Research Methods & Reporting
Economic evaluation using decision analytical modelling: design, conduct, analysis, and reporting
Stavros Petrou, Alastair Gray
BMJ 2011;342:doi:10.1136/bmj.d1766 (Published 11 April 2011)

Extract
Evidence relating to healthcare decisions often comes from more than one study. Decision analytical modelling can be used as a basis for economic evaluations in these situations.

Economic evaluations are increasingly conducted alongside randomised controlled trials, providing researchers with individual patient data to estimate cost effectiveness. 1 However, randomised trials do not always provide a sufficient basis for economic evaluations used to inform regulatory and reimbursement decisions. For example, a single trial might not compare all the available options, provide evidence on all relevant inputs, or be conducted over a long enough time to capture differences in economic outcomes (or even measure those outcomes). 2 In addition, reliance on a single trial may mean ignoring evidence from other trials, meta-analyses, and observational studies. Under these circumstances, decision analytical modelling provides an alternative framework for economic evaluation.

Decision analytical modelling compares the expected costs and consequences of decision options by synthesising information from multiple sources and applying mathematical techniques, usually with computer software. The aim is to provide decision makers with the best available evidence to reach a decision—for example, should a new drug be adopted? Following on from our article on trial based economic evaluations, 1 we outline issues relating to the design, conduct, analysis, and reporting of economic evaluations using decision analytical modelling.

Glossary of terms

– Cost effectiveness acceptability curve—Graphical depiction of the probability that a health intervention is cost effective across a range of willingness to pay thresholds held by decision makers for the health outcome of interest

– Cost effectiveness plane—Graphical depiction of difference in effectiveness between the new treatment and the comparator against the difference in cost

– Discounting—The practice of reducing future costs and health outcomes to present values

– Health utilities—Preference based outcomes normally represented on a scale where 0 represents death and 1 represents perfect …