eprintid: 10079176
rev_number: 18
eprint_status: archive
userid: 608
dir: disk0/10/07/91/76
datestamp: 2019-08-02 09:24:01
lastmod: 2021-12-05 00:38:56
status_changed: 2019-08-02 09:24:01
type: article
metadata_visibility: show
creators_name: Cook, JA
creators_name: Julious, SA
creators_name: Sones, W
creators_name: Hampson, LV
creators_name: Hewitt, C
creators_name: Berlin, JA
creators_name: Ashby, D
creators_name: Emsley, R
creators_name: Fergusson, DA
creators_name: Walters, SJ
creators_name: Wilson, ECF
creators_name: Maclennan, G
creators_name: Stallard, N
creators_name: Rothwell, JC
creators_name: Bland, M
creators_name: Brown, L
creators_name: Ramsay, CR
creators_name: Cook, A
creators_name: Armstrong, D
creators_name: Altman, D
creators_name: Vale, LD
title: DELTA(2) guidance on choosing the target difference and undertaking and reporting the sample size calculation for a randomised controlled trial
ispublished: pub
divisions: UCL
divisions: B02
divisions: D65
divisions: J38
note: This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
abstract: Background: A key step in the design of a RCT is the estimation of the number of participants needed in the study.
The most common approach is to specify a target difference between the treatments for the primary outcome and
then calculate the required sample size. The sample size is chosen to ensure that the trial will have a high probability
(adequate statistical power) of detecting a target difference between the treatments should one exist.
The sample size has many implications for the conduct and interpretation of the study. Despite the critical role that the
target difference has in the design of a RCT, the way in which it is determined has received little attention. In this
article, we summarise the key considerations and messages from new guidance for researchers and funders on
specifying the target difference, and undertaking and reporting a RCT sample size calculation. This article on
choosing the target difference for a randomised controlled trial (RCT) and undertaking and reporting the sample
size calculation has been dual published in the BMJ and BMC Trials journals
Methods: The DELTA2 (Difference ELicitation in TriAls) project comprised five major components: systematic literature
reviews of recent methodological developments (stage 1) and existing funder guidance (stage 2); a Delphi study
(stage 3); a two-day consensus meeting bringing together researchers, funders and patient representatives (stage 4);
and the preparation and dissemination of a guidance document (stage 5).
Results and Discussion: The key messages from the DELTA2 guidance on determining the target difference and
sample size calculation for a randomised caontrolled trial are presented. Recommendations for the subsequent
reporting of the sample size calculation are also provided.
date: 2018-11-05
date_type: published
publisher: BMC
official_url: https://doi.org/10.1186/s13063-018-2884-0
oa_status: green
full_text_type: pub
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 1600614
doi: 10.1186/s13063-018-2884-0
lyricists_name: Brown, Louise
lyricists_id: LCBRO59
actors_name: Brown, Louise
actors_id: LCBRO59
actors_role: owner
full_text_status: public
publication: Trials
volume: 19
article_number: 606
pages: 8
issn: 1745-6215
citation:        Cook, JA;    Julious, SA;    Sones, W;    Hampson, LV;    Hewitt, C;    Berlin, JA;    Ashby, D;                                                         ... Vale, LD; + view all <#>        Cook, JA;  Julious, SA;  Sones, W;  Hampson, LV;  Hewitt, C;  Berlin, JA;  Ashby, D;  Emsley, R;  Fergusson, DA;  Walters, SJ;  Wilson, ECF;  Maclennan, G;  Stallard, N;  Rothwell, JC;  Bland, M;  Brown, L;  Ramsay, CR;  Cook, A;  Armstrong, D;  Altman, D;  Vale, LD;   - view fewer <#>    (2018)    DELTA(2) guidance on choosing the target difference and undertaking and reporting the sample size calculation for a randomised controlled trial.                   Trials , 19     , Article 606.  10.1186/s13063-018-2884-0 <https://doi.org/10.1186/s13063-018-2884-0>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10079176/1/DELTA2%20guidance%20on%20choosing%20the%20target%20difference%20and%20undertaking%20and%20reporting%20the%20sample%20size%20calculation%20for%20a%20randomised.pdf