| Title |
Specifying the target difference in the primary outcome for a randomised controlled trial: guidance for researchers
|
|---|---|
| Published in |
Trials, January 2015
|
| DOI | 10.1186/s13063-014-0526-8 |
| Pubmed ID | |
| Authors |
Jonathan A Cook, Jenni Hislop, Douglas G Altman, Peter Fayers, Andrew H Briggs, Craig R Ramsay, John D Norrie, Ian M Harvey, Brian Buckley, Dean Fergusson, Ian Ford, Luke D Vale |
| Abstract |
Central to the design of a randomised controlled trial is the calculation of the number of participants needed. This is typically achieved by specifying a target difference and calculating the corresponding sample size, which provides reassurance that the trial will have the required statistical power (at the planned statistical significance level) to identify whether a difference of a particular magnitude exists. Beyond pure statistical or scientific concerns, it is ethically imperative that an appropriate number of participants should be recruited. Despite the critical role of the target difference for the primary outcome in the design of randomised controlled trials, its determination has received surprisingly little attention. This article provides guidance on the specification of the target difference for the primary outcome in a sample size calculation for a two parallel group randomised controlled trial with a superiority question. |
X Demographics
The data shown below were collected from the profiles of 27 X users who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United Kingdom | 10 | 37% |
| Netherlands | 2 | 7% |
| Australia | 1 | 4% |
| United States | 1 | 4% |
| Ireland | 1 | 4% |
| Germany | 1 | 4% |
| Unknown | 11 | 41% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 14 | 52% |
| Scientists | 7 | 26% |
| Practitioners (doctors, other healthcare professionals) | 4 | 15% |
| Science communicators (journalists, bloggers, editors) | 2 | 7% |
Mendeley readers
The data shown below were compiled from readership statistics for 119 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United Kingdom | 3 | 3% |
| Australia | 2 | 2% |
| France | 1 | <1% |
| Germany | 1 | <1% |
| United States | 1 | <1% |
| Unknown | 111 | 93% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Researcher | 26 | 22% |
| Other | 16 | 13% |
| Student > Ph. D. Student | 13 | 11% |
| Student > Master | 11 | 9% |
| Professor | 8 | 7% |
| Other | 25 | 21% |
| Unknown | 20 | 17% |
| Readers by discipline | Count | As % |
|---|---|---|
| Medicine and Dentistry | 44 | 37% |
| Psychology | 10 | 8% |
| Mathematics | 9 | 8% |
| Nursing and Health Professions | 6 | 5% |
| Economics, Econometrics and Finance | 5 | 4% |
| Other | 19 | 16% |
| Unknown | 26 | 22% |
Attention Score in Context
This research output has an Altmetric Attention Score of 26. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 08 February 2022.
All research outputs
#1,343,546
of 23,607,611 outputs
Outputs from Trials
#347
of 6,083 outputs
Outputs of similar age
#20,956
of 383,276 outputs
Outputs of similar age from Trials
#5
of 86 outputs
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So far Altmetric has tracked 6,083 research outputs from this source. They typically receive more attention than average, with a mean Attention Score of 8.4. This one has done particularly well, scoring higher than 94% of its peers.
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We're also able to compare this research output to 86 others from the same source and published within six weeks on either side of this one. This one has done particularly well, scoring higher than 95% of its contemporaries.