Introduction to dynamic treatment strategies and sequential multiple assignment randomization

Abstract

Background In June 2013, a 1-day workshop on Dynamic Treatment Strategies (DTSs) and Sequential Multiple Assignment Randomized Trials (SMARTs) was held at the University of Pennsylvania in Philadelphia, Pennsylvania. These two linked topics have generated a great deal of interest as researchers have recognized the importance of comparing entire strategies for managing chronic disease. A number of articles emerged from that workshop. Purpose The purpose of this survey of the DTS/SMART methodology (which is taken from the introductory talk in the workshop) is to provide the reader the collected articles presented in this volume with sufficient background to appreciate the more detailed discussions in the articles. Methods The way that the DTS arises naturally in clinical practice is described, along with its connection to the well-known difficulties of interpreting the analysis by intention-to-treat. The SMART methodology for comparing DTS is described, and the basics of estimation and inference presented. Results The DTS/SMART methodology can be a flexible and practical way to optimize ongoing clinical decision making, providing evidence (based on randomization) for comparative effectiveness. Limitations The DTS/SMART methodology is not a solution for unstandardized study protocols. Conclusions The DTS/SMART methodology has growing relevance to comparative effectiveness research and the needs of the learning healthcare system.