A pragmatic-explanatory continuum indicator summary (PRECIS): a tool to help trial designers

Kevin E. Thorpe, Merrick Zwarenstein, Andrew D. Oxman, Shaun Treweek, Curt D. Furberg, Douglas G. Altman, Sean Tunis, Eduardo Bergel, Ian Harvey, David J. Magid, Kalipso Chalkidou

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    631 Citations (Scopus)


    Objective: To propose a tool to assist trialists in making design decisions that are consistent with their trial's stated purpose.

    Study Design and Setting: Randomized trials have been broadly categorized as either having a pragmatic or explanatory attitude. Pragmatic trials seek to answer the question, "Does this intervention work under usual conditions?," whereas explanatory trials are focused on the question, "Can this intervention work under ideal conditions?" Design decisions make a trial more (or less) pragmatic or explanatory, but no tool currently exists to help researchers make the best decisions possible in accordance with their trial's primary goal. During the course of two international meetings, participants with experience in clinical care, research commissioning, health care financing, trial methodology, and reporting defined and refined aspects of trial design that distinguish pragmatic attitudes from explanatory.

    Results: We have developed a tool (called PRECIS) with 10 key domains and which identifies criteria to help researchers determine how pragmatic or explanatory their trial is. The assessment is summarized graphically.

    Conclusion: We believe that PRECIS is a useful first step toward a tool that can help trialists to ensure that their design decisions are consistent with the stated purpose of the trial. (C) 2009 The Authors. Published by Elsevier Inc. All rights reserved.

    Original languageEnglish
    Pages (from-to)464-475
    Number of pages12
    JournalJournal of Clinical Epidemiology
    Issue number5
    Publication statusPublished - May 2009


    • Randomized controlled trials
    • Clinical trial methodology
    • Pragmatic trial
    • Explanatory trial
    • Trial design
    • Clinical trial

    Cite this

    Thorpe, K. E., Zwarenstein, M., Oxman, A. D., Treweek, S., Furberg, C. D., Altman, D. G., Tunis, S., Bergel, E., Harvey, I., Magid, D. J., & Chalkidou, K. (2009). A pragmatic-explanatory continuum indicator summary (PRECIS): a tool to help trial designers. Journal of Clinical Epidemiology, 62(5), 464-475. https://doi.org/10.1016/j.jclinepi.2008.12.011