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DELTA2 guidance on choosing the target difference and undertaking and reporting the sample size calculation for a randomised controlled trial

DELTA2 guidance on choosing the target difference and undertaking and reporting the sample size calculation for a randomised controlled trial
DELTA2 guidance on choosing the target difference and undertaking and reporting the sample size calculation for a randomised controlled trial
The randomised controlled trial (RCT) is considered the gold standard to assess comparative clinical efficacy and effectiveness and can be a key source of data for estimating cost- effectiveness. Central to the design of a RCT is an a-priori sample size calculation which ensures the study has a high probability of achieving its pre-specified main objective. Beyond pure statistical or scientific concerns, it is ethically imperative that an appropriate number of study participants be recruited, to avoid imposing the burdens of a clinical trial on more patients than necessary. The scientific concern is satisfied and the ethical imperative further addressed by specifying a target difference between treatments that is considered realistic and/or important by one or more key stakeholder groups. The sample size calculation ensures that the trial will have the required statistical power to identify whether a difference of a particular magnitude exists. The key messages from the DELTA2 guidance on determining the target difference and sample size calculation for a RCT are presented. Recommendations for the subsequent reporting of the sample size calculation are also provided.
0959-8138
Cook, Jonathan A.
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Julious, Stephen A.
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Sones, William
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Hampson, Lisa V.
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Hewitt, Catherine
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Berlin, Jesse A.
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Ashby, Deborah
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Emsley, Richard
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Fergusson, Dean A.
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Walters, Stephen J.
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Wilson, Edward C.F.
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McLennan, Graeme
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Stallard, Nigel
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Rothwell, Joanne C.
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Bland, Martin
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Brown, Louise
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Ramsay, Craig R.
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Cook, Andrew
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Armstrong, David
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Altman, Doug
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Vale, Luke D.
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Cook, Jonathan A.
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Julious, Stephen A.
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Sones, William
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Hampson, Lisa V.
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Hewitt, Catherine
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Berlin, Jesse A.
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Ashby, Deborah
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Emsley, Richard
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Fergusson, Dean A.
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Walters, Stephen J.
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Wilson, Edward C.F.
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McLennan, Graeme
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Stallard, Nigel
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Rothwell, Joanne C.
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Bland, Martin
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Brown, Louise
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Ramsay, Craig R.
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Cook, Andrew
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Armstrong, David
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Altman, Doug
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Vale, Luke D.
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Cook, Jonathan A., Julious, Stephen A., Sones, William, Hampson, Lisa V., Hewitt, Catherine, Berlin, Jesse A., Ashby, Deborah, Emsley, Richard, Fergusson, Dean A., Walters, Stephen J., Wilson, Edward C.F., McLennan, Graeme, Stallard, Nigel, Rothwell, Joanne C., Bland, Martin, Brown, Louise, Ramsay, Craig R., Cook, Andrew, Armstrong, David, Altman, Doug and Vale, Luke D. (2018) DELTA2 guidance on choosing the target difference and undertaking and reporting the sample size calculation for a randomised controlled trial. BMJ, [363]. (doi:10.1136/bmj.k3750).

Record type: Article

Abstract

The randomised controlled trial (RCT) is considered the gold standard to assess comparative clinical efficacy and effectiveness and can be a key source of data for estimating cost- effectiveness. Central to the design of a RCT is an a-priori sample size calculation which ensures the study has a high probability of achieving its pre-specified main objective. Beyond pure statistical or scientific concerns, it is ethically imperative that an appropriate number of study participants be recruited, to avoid imposing the burdens of a clinical trial on more patients than necessary. The scientific concern is satisfied and the ethical imperative further addressed by specifying a target difference between treatments that is considered realistic and/or important by one or more key stakeholder groups. The sample size calculation ensures that the trial will have the required statistical power to identify whether a difference of a particular magnitude exists. The key messages from the DELTA2 guidance on determining the target difference and sample size calculation for a RCT are presented. Recommendations for the subsequent reporting of the sample size calculation are also provided.

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Delta2_Gudiance paper V10 - 26-7-18 BMJ - Accepted Manuscript
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Accepted/In Press date: 10 August 2018
e-pub ahead of print date: 5 November 2018

Identifiers

Local EPrints ID: 424782
URI: http://eprints.soton.ac.uk/id/eprint/424782
ISSN: 0959-8138
PURE UUID: db03fbbe-f007-439e-9612-bce6d0c5e1a2
ORCID for Andrew Cook: ORCID iD orcid.org/0000-0002-6680-439X

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Date deposited: 05 Oct 2018 11:45
Last modified: 11 May 2024 01:41

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Contributors

Author: Jonathan A. Cook
Author: Stephen A. Julious
Author: William Sones
Author: Lisa V. Hampson
Author: Catherine Hewitt
Author: Jesse A. Berlin
Author: Deborah Ashby
Author: Richard Emsley
Author: Dean A. Fergusson
Author: Stephen J. Walters
Author: Edward C.F. Wilson
Author: Graeme McLennan
Author: Nigel Stallard
Author: Joanne C. Rothwell
Author: Martin Bland
Author: Louise Brown
Author: Craig R. Ramsay
Author: Andrew Cook ORCID iD
Author: David Armstrong
Author: Doug Altman
Author: Luke D. Vale

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