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Comparison of registered and published outcomes in randomized controlled trials: a systematic review

Overview of attention for article published in BMC Medicine, November 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 (97th percentile)
  • High Attention Score compared to outputs of the same age and source (83rd percentile)

Mentioned by

news
2 news outlets
blogs
3 blogs
twitter
48 tweeters
reddit
1 Redditor

Citations

dimensions_citation
150 Dimensions

Readers on

mendeley
77 Mendeley
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Title
Comparison of registered and published outcomes in randomized controlled trials: a systematic review
Published in
BMC Medicine, November 2015
DOI 10.1186/s12916-015-0520-3
Pubmed ID
Authors

Christopher W. Jones, Lukas G. Keil, Wesley C. Holland, Melissa C. Caughey, Timothy F. Platts-Mills

Abstract

Clinical trial registries can improve the validity of trial results by facilitating comparisons between prospectively planned and reported outcomes. Previous reports on the frequency of planned and reported outcome inconsistencies have reported widely discrepant results. It is unknown whether these discrepancies are due to differences between the included trials, or to methodological differences between studies. We aimed to systematically review the prevalence and nature of discrepancies between registered and published outcomes among clinical trials. We searched MEDLINE via PubMed, EMBASE, and CINAHL, and checked references of included publications to identify studies that compared trial outcomes as documented in a publicly accessible clinical trials registry with published trial outcomes. Two authors independently selected eligible studies and performed data extraction. We present summary data rather than pooled analyses owing to methodological heterogeneity among the included studies. Twenty-seven studies were eligible for inclusion. The overall risk of bias among included studies was moderate to high. These studies assessed outcome agreement for a median of 65 individual trials (interquartile range [IQR] 25-110). The median proportion of trials with an identified discrepancy between the registered and published primary outcome was 31 %; substantial variability in the prevalence of these primary outcome discrepancies was observed among the included studies (range 0 % (0/66) to 100 % (1/1), IQR 17-45 %). We found less variability within the subset of studies that assessed the agreement between prospectively registered outcomes and published outcomes, among which the median observed discrepancy rate was 41 % (range 30 % (13/43) to 100 % (1/1), IQR 33-48 %). The nature of observed primary outcome discrepancies also varied substantially between included studies. Among the studies providing detailed descriptions of these outcome discrepancies, a median of 13 % of trials introduced a new, unregistered outcome in the published manuscript (IQR 5-16 %). Discrepancies between registered and published outcomes of clinical trials are common regardless of funding mechanism or the journals in which they are published. Consistent reporting of prospectively defined outcomes and consistent utilization of registry data during the peer review process may improve the validity of clinical trial publications.

Twitter Demographics

The data shown below were collected from the profiles of 48 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 %
Spain 1 1%
Bangladesh 1 1%
Norway 1 1%
Unknown 74 96%

Demographic breakdown

Readers by professional status Count As %
Student > Master 16 21%
Researcher 14 18%
Student > Bachelor 13 17%
Student > Ph. D. Student 8 10%
Student > Doctoral Student 6 8%
Other 13 17%
Unknown 7 9%
Readers by discipline Count As %
Medicine and Dentistry 33 43%
Social Sciences 7 9%
Psychology 4 5%
Nursing and Health Professions 4 5%
Agricultural and Biological Sciences 3 4%
Other 11 14%
Unknown 15 19%

Attention Score in Context

This research output has an Altmetric Attention Score of 60. 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 24 January 2021.
All research outputs
#455,253
of 18,360,230 outputs
Outputs from BMC Medicine
#363
of 2,784 outputs
Outputs of similar age
#11,135
of 378,659 outputs
Outputs of similar age from BMC Medicine
#49
of 296 outputs
Altmetric has tracked 18,360,230 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 97th percentile: it's in the top 5% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 2,784 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 39.3. This one has done well, scoring higher than 86% 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 378,659 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 97% of its contemporaries.
We're also able to compare this research output to 296 others from the same source and published within six weeks on either side of this one. This one has done well, scoring higher than 83% of its contemporaries.