The Quality of Registration of Clinical Trials: Still a Problem

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Date: Jan. 10, 2014
From: PLoS ONE(Vol. 9, Issue 1)
Publisher: Public Library of Science
Document Type: Article
Length: 7,218 words
Lexile Measure: 1810L

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Author(s): Roderik F. Viergever 1,2,*, Ghassan Karam 3, Andreas Reis 4, Davina Ghersi 5


Clinical trials registration is now broadly considered an ethical and scientific responsibility.[1]-[8] In the past fifteen years, national and regional trial registries have been established in Africa, Asia, Australia/Oceania, Europe, North America and South America.[9] The WHO International Clinical Trials Registry Platform (ICTRP) was established in 2005 with the aim of bringing registered trial data from different trial registries together and creating a single point of access to information on all clinical trials conducted globally.[10] It now combines data from 15 national and regional clinical trial registries, offering access to data from more than 200,000 trials.

There are important advantages to the increased transparency on clinical trial conduct and reporting brought about by these developments. It improves access to information on clinical trials for healthcare workers, researchers and patients [11], [12]; it allows for steps to be taken against publication bias and selective reporting [2], [12]-[20]; it carries the potential to increase the accountability of those conducting clinical trial research; and it makes the identification of gaps in the health research landscape possible, thus facilitating priority setting in research [21]-[27].

The degree to which registered trial data can be used for these purposes depends on the completeness and meaningfulness of the data registered. The quality of data in registered records has been shown to be poor in the past.[2], [14], [15], [28]-[41] However, clinical trials registration has matured in recent years. Trialists may have gotten better at registering. Moreover, registries are likely to have improved their registration systems after the implementation of the International Standards for Clinical Trial Registries in 2010.[42]

This study was conducted to investigate whether the poor quality of registration observed in the past has been due to trial registration being in its nascence, or whether it is a more persistent problem. To do so, we repeated a study conducted by us in 2009, using the same methods and the same research team.[2]


A random sample of 400 registered records of clinical trials that were registered between 1 January 2012 and 1 January 2013 was taken from the ICTRP database. Records of trials that were registered as having an observational study design were not eligible for the sample. For trials that were registered in more than one registry (duplicate records), only the record with the earliest registration date was considered eligible.[43] At the time the sample was taken the database included trials registered in fifteen different registries.[9]

Sample size calculation

A sample size of 380 records was chosen, to ensure that all upper and lower 95% confidence intervals for extrapolation to the entire ICTRP dataset, calculated using the Wilson score interval (see further under analysis), would deviate 5% at most from the estimated number. A sample size of 380 also fulfilled this study's requirements to detect relatively minor changes in the quality of the three primary outcomes: the quality of contact details, interventions and outcomes (minor changes were defined as a...

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Gale Document Number: GALE|A478870836