Commentary
PRECIS-2 in perspective: what is next for pragmatic trials?

https://doi.org/10.1016/j.jclinepi.2016.02.027Get rights and content

Introduction

The PRECIS-2 tool has been introduced to support trialists in making design choices consistent with the intended purpose of the trial, be it explanatory or pragmatic [1]. Using PRECIS-2, a multidisciplinary team can score a trial design in a four-step process on nine domains to determine if the trial design matches the intended use of the trial results. This is an important advancement of the original PRECIS tool [2], now providing a guidance article with optimized domains. As the authors state in their article, tools such as PRECIS-2 will not provide the one “correct” answer, but they can help trial designers to explicitly match design decisions to the intended use of the trial results and assist in obtaining consistency in decision making. We fully endorse the thinking behind the PRECIS-2 tool and the importance of making design choices for trials more explicit and see the PRECIS-2 tool as an important addition to the literature on pragmatic and explanatory trials.

In this commentary, we would like to raise three discussion points with regard to PRECIS-2 and present our vision on how to bring this tool even further, from the drawing board into the practice of trial conduct.

Section snippets

Is a good match between trial and usual care conditions always necessary?

Quote: “If trialists are aiming for high applicability (that is, a pragmatic approach to design decisions), then we would expect the match between trial and usual care to be very good.”

This is indeed often the strategy chosen to ensure high generalizability of the results of a pragmatic trial. But what drives generalizability? Any clinical or nonclinical characteristic of a patient that has an impact on the benefit or risk of a treatment (modifiers of drug response) and may be differently

Can we leave comparator choice out of the PRECIS-2 equation?

Quote: “In pragmatic trials the comparator is usual care. In explanatory trials it may not be. In PRECIS-2, the domains are based on the assumption that the trial is two armed, one of which is usual care with no changes.”

The comparator choice is not discussed in PRECIS-2 but is assumed to be usual care as a single arm in which no changes are made. Although conceptually straightforward, the way this is interpreted or realized in trials may vary substantially [4], [5], [6], [7], [8]. In pragmatic

How suitable is PRECIS-2 when aiming to take an explanatory approach?

Quote: “PRECIS is a tool to help trialists make design decisions consistent with the intended purpose of their trial” where 9 domains are “scored from 1 (very explanatory) to 5 (very pragmatic).”

PRECIS-2 is not solely about pragmatic trails but about the design choices meeting the research question, be it pragmatic or explanatory. However, for most domains, the pragmatic approach is well explained, whereas the explanatory approach (e.g., why score methods to monitor and ensure patient

From the drawing board into the practice of trial conduct

Quote: PRECIS-2 “does not remove the need for judgement (of design decisions) because there is no single ‘correct’ answer. The advantage of PRECIS-2 is that it makes these judgements explicit and therefore able to be discussed by the trial team”; it “raises awareness of the need to explicitly consider the match between design decisions (and the consequences of these) and the usefulness of the future results to the intended audience.”

PRECIS-2 is a valuable tool in assessing the theoretical match

Acknowledgments

The work leading to these results has received support from the Innovative Medicines Initiative Joint Undertaking under grant agreement no (115546), resources of which are composed of financial contribution from the European Union's Seventh Framework Programme (FP7/2007/2013) and EFPIA companies in kind contribution. The research leading to these results was conducted as part of the GetReal consortium. For further information, please refer to http://www.imi-getreal.eu/. This article only

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References (15)

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