Randomised Trials using Adaptive Designs

This CONSORT extension is meant to provide reporting guidance for any randomised trial that was designed using an adaptive design. By an adaptive design, we mean a design that allows pre-planned changes to aspects of the trial (adaptations) to be made based on interim trial data without undermining the validity of conclusions. Such adaptations may include options for changing the pre-determined sample size, early stopping of treatment groups for efficacy or futility, changes to the randomisation ratios to favour the allocation of treatments showing beneficial effects, modifying eligibility criteria to focus on study participants showing promising benefits, or a combination of these. These changes exclude those that relate to operational feasibility of the trial, which is addressed in the CONSORT extension for randomised pilot and feasibility trials. This Adaptive designs CONSORT Extension (ACE) provides general reporting principles that apply regardless of the nature of adaptation(s) considered, other trial design characteristics (e.g. cluster, cross-over, multi-arm, factorial, platform, non-inferiority), and whether frequentist or Bayesian methods were used. The ACE should be used alongside other relevant CONSORT extensions depending on other design characteristics of the trial.

We strongly encourage the ACE users to read the statement document (below) which details the scope of the extension, what is expected to be reported under each item with explanation, and examples. ACE users should note that these are minimum essential reporting standards and additional information should be reported if it enhances the reproducibility of methods and interpretation of results, which can be challenging for complex adaptive designs. 

There are new and replacement items that are only applied by referencing to ACE. Modified items require referencing to both CONSORT 2010 and ACE. In some items, the wording of the item on the checklist remained unchanged (in reference to CONSORT 2010), however, the ACE explanatory text was expanded to clarify additional considerations for specific adaptive designs. These should be applied in reference to both CONSORT 2010 and ACE unless it is indicated otherwise. 

Available Downloads

Document Word Format PDF Format
Statement Document n/a Download
Checklist Download n/a
Abstract Checklist Download n/a
Flowchata

Appendix D

Appendix E

Appendix F

Appendix G

Appendix H

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a. note that these examples are not exhaustive as the flowchart structure depends on the type of adaptive design used, stage of reporting, and nature of interim decisions made. 

References

Dimairo M, Pallmann P, Wason J, Todd S, Jaki T, Julious SA, Mander AP, Weir CJ, Koenig F, Walton MK, Nicholl JP, Coates E, Biggs K, Hamasaki T, Proschan MA, Scott JA, Ando Y, Hind D, Altman DG; ACE Consensus Group. The Adaptive designs CONSORT Extension (ACE) statement: a checklist with explanation and elaboration guideline for reporting randomised trials that use an adaptive design. BMJ. 2020 Jun 17;369:m115. PMID: 32554564; PMCID: PMC7298567.

 

Dimairo M, Pallmann P, Wason J, Todd S, Jaki T, Julious SA, Mander AP, Weir CJ, Koenig F, Walton MK, Nicholl JP, Coates E, Biggs K, Hamasaki T, Proschan MA, Scott JA, Ando Y, Hind D, Altman DG; ACE Consensus Group. The adaptive designs CONSORT extension (ACE) statement: a checklist with explanation and elaboration guideline for reporting randomised trials that use an adaptive design. Trials. 2020 Jun 17;21(1):528. PMID: 32546273; PMCID: PMC7298968.

 

Dimairo M, Coates E, Pallmann P, Todd S, Julious SA, Jaki T, Wason J, Mander AP, Weir CJ, Koenig F, Walton MK, Biggs K, Nicholl J, Hamasaki T, Proschan MA, Scott JA, Ando Y, Hind D, Altman DG. Development process of a consensus-driven CONSORT extension for randomised trials using an adaptive design. BMC Med. 2018 Nov 16;16(1):210. PMID: 30442137; PMCID: PMC6238302.