A Study Design for Augmenting the Control Group in a Randomized Controlled Trial: A Quality Process for Interaction Among Stakeholders.

There is an increasing demand for utilization of external data, such as historical study data and patient registry data, to augment the control group in a randomized controlled trial. While such a study design could reduce the time and cost, how to maintain the study validity and integrity is one major statistical challenge that needs to be carefully addressed. We discuss a study design quality process to enhance the study validity and integrity when using this approach. The discussed quality process is tailored to the confirmatory study using a 2-stage design with an emphasis on the interaction process among stakeholders. In an example, the quality process covers a 2-step assessment of the similarity in patient characteristics between the current study and the external data source, and between the treatment and augmented control groups.