Health Economics in Clinical Trials

Based on Drummond, Sculpher, Torrance, O'Brien & Stoddart, 2005.
Randomised controlled clinical trials have both strengths and weaknesses for economic evaluation. In general there are two ways to incorporate economic questions into a trial – either by including economic evaluation within an existing efficacy or safety trial, or through the design of a pragmatic trial specifically for the purpose of economic evaluation.

Given that randomised controlled trials are the accepted gold standard for assessing safety and efficacy, it is reasonable to consider collecting economic data within an existing clinical trial. This allows prospective collection of patient level cost and outcomes data, while utilising the existing trial infrastructure and therefore requiring minimal additional resources. However issues such as the comparison of new treatments to placebos, the use of surrogate endpoints and a lack of long term follow up can limit the ability of trials designed primarily for a clinical purpose to answer economic questions.

Alternatively, pragmatic trials can be designed specifically to answer economic evaluation questions. These trials minimise bias through random allocation, but aim to assess the effectiveness or cost-effectiveness of an intervention under ‘real world' conditions, by having fewer restrictions on patient recruitment and follow up. This allows greater generalisability of results. Difficulties in comparing more than two or three treatment options and a lack of long term follow up are still present in pragmatic trials and need to be addressed in the design phase.

Finally, economic modelling can be used when evidence from a range of sources is required for decision making. Data sources such as cohort studies and surveys can be used alongside clinical trials to obtain clinical, cost and quality of life information for use in decision analytic models. Coming soon to the CREST website will be a range of resources, including some providing an introduction to and further readings on health economics in clinical trials.