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Logo of bmcmrmBioMed Centralsearchsubmit a manuscriptregisterthis articleBMC Medical Research Methodology
BMC Med Res Methodol. 2012; 12: 101.
Published online 2012 July 23. doi:  10.1186/1471-2288-12-101
PMCID: PMC3477062

How pragmatic or explanatory is the randomized, controlled trial? The application and enhancement of the PRECIS tool to the evaluation of a smoking cessation trial



Numerous explanatory randomized trials support the efficacy of chronic disease interventions, including smoking cessation treatments. However, there is often inadequate adoption of these interventions for various reasons, one being the limitation of generalizability of the explanatory studies in real-world settings. Randomized controlled trials can be rated as more explanatory versus pragmatic along 10 dimensions. Pragmatic randomized clinical trials generate more realistic estimates of effectiveness with greater relevance to clinical practice and for health resource allocation decisions. However, there is no clear method to scale each dimension during the trial design phase to ensure that the design matches the intended purpose of the study.


We designed a pragmatic, randomized, controlled study to maximize external validity by addressing several barriers to smoking cessation therapy in ambulatory care. We analyzed our design and methods using the recently published ‘Pragmatic–Explanatory Continuum Indicatory Summary (PRECIS)’ tool, a qualitative method to assess trial design across 10 domains. We added a 20-point numerical rating scale and a modified Delphi process to improve consensus in rating these domains.


After two rounds of review, there was consensus on all 10 domains of study design. No single domain was scored as either fully pragmatic or fully explanatory; but overall, the study scored high on pragmatism.


This addition to the PRECIS tool may assist other trial designers working with interdisciplinary co-investigators to rate their study design while building consensus.

Keywords: Clinical trial, Explanatory, Pragmatic, Smoking cessation, PRECIS, Varenicline, Bupropion, Nicotine replacement therapy

Articles from BMC Medical Research Methodology are provided here courtesy of BioMed Central