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Sharing data from clinical trials: the rationale for a controlled access approach

Overview of attention for article published in Trials, March 2015
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About this Attention Score

  • In the top 5% of all research outputs scored by Altmetric
  • High Attention Score compared to outputs of the same age (94th percentile)

Mentioned by

60 tweeters
1 Facebook page
1 Google+ user


51 Dimensions

Readers on

77 Mendeley
1 CiteULike
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Sharing data from clinical trials: the rationale for a controlled access approach
Published in
Trials, March 2015
DOI 10.1186/s13063-015-0604-6
Pubmed ID

Matthew R Sydes, Anthony L Johnson, Sarah K Meredith, Mary Rauchenberger, Annabelle South, Mahesh KB Parmar


The move towards increased transparency around clinical trials is welcome. Much focus has been on under-reporting of trials and access to individual patient data to allow independent verification of findings. There are many other good reasons for data sharing from clinical trials. We describe some key issues in data sharing, including the challenges of open access to data. These include issues in consent and disclosure; risks in identification, including self-identification; risks in distorting data to prevent self-identification; and risks in analysis. These risks have led us to develop a controlled access policy, which safeguards the rights of patients entered in our trials, guards the intellectual property rights of the original researchers who designed the trial and collected the data, provides a barrier against unnecessary duplication, and ensures that researchers have the necessary resources and skills to analyse the data. We briefly discuss the practicalities of our current approach to data sharing, including ensuring that data are discoverable and how to deal with old studies. We describe data sharing activities at the MRC Clinical Trials Unit. One hundred and three data sharing activities were logged from 2012 to 2014 from external and internal applicants. The motivations are varied, but none have been for replication of the primary results. For any request to share data, we note the important role of independent reviewers as well as reviewers who know the study well, and present some of the key questions that all reviewers should ask when deciding whether a request is reasonable. We consider the responsibilities of all parties. We highlight the potential for opportunity costs. Clinical trial data should be shared for reasonable requests but there are many practical issues that must be explicitly considered.

Twitter Demographics

The data shown below were collected from the profiles of 60 tweeters who shared this research output. Click here to find out more about how the information was compiled.

Mendeley readers

The data shown below were compiled from readership statistics for 77 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
United States 1 1%
Netherlands 1 1%
Greece 1 1%
Unknown 74 96%

Demographic breakdown

Readers by professional status Count As %
Researcher 16 21%
Student > Ph. D. Student 11 14%
Student > Master 8 10%
Other 6 8%
Professor > Associate Professor 6 8%
Other 21 27%
Unknown 9 12%
Readers by discipline Count As %
Medicine and Dentistry 27 35%
Agricultural and Biological Sciences 7 9%
Computer Science 6 8%
Psychology 3 4%
Social Sciences 3 4%
Other 15 19%
Unknown 16 21%

Attention Score in Context

This research output has an Altmetric Attention Score of 35. 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 03 February 2019.
All research outputs
of 21,435,803 outputs
Outputs from Trials
of 5,485 outputs
Outputs of similar age
of 239,678 outputs
Outputs of similar age from Trials
of 1 outputs
Altmetric has tracked 21,435,803 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 95th percentile: it's in the top 5% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 5,485 research outputs from this source. They typically receive more attention than average, with a mean Attention Score of 7.9. This one has done particularly well, scoring higher than 96% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 239,678 tracked outputs that were published within six weeks on either side of this one in any source. This one has done particularly well, scoring higher than 94% of its contemporaries.
We're also able to compare this research output to 1 others from the same source and published within six weeks on either side of this one. This one has scored higher than all of them