A study published in BMC Medicine this week assessed the consistency between the reporting of serious adverse events (SAEs) posted at ClinicalTrials.gov and those published in corresponding journal articles.

Key findings (also see the Figure below) were as follows:

• Among a sample of 300 trials with SAEs posted at ClinicalTrials.gov, 78 (26%) did not have a corresponding publication, and 20 (7%) had a publication that did not match the ClinicalTrials.gov record.
• For the 202 remaining trials, 26 published articles (13%) did not mention SAEs, 4 (2%) reported no SAEs, and 33 (16%) did not report the total number of SAEs per treatment group.
• Among the remaining 139 trials, for 44 (32%), the number of SAEs per group published did not match those posted at ClinicalTrials.gov.
• For 31 trials, the number of SAEs was greater at ClinicalTrials.gov than in the published article, with a difference ≥30% for at least one group for 21.
• Only 33 trials (11%) had a publication reporting matching numbers of SAE and describing the type of SAE.

The authors concluded: “Many trials with SAEs posted at ClinicalTrials.gov are not yet published, omit the reporting of these SAEs in corresponding publications, or report a discrepant number of SAEs as compared with ClinicalTrials.gov. These results underline the need to consult ClinicalTrials.gov for more information on serious harms.”.

Figure: Reporting of serious adverse events (SAEs) in published articles for a random sample of 300 trials with SAEs posted at ClinicalTrials.gov. Tang et al. BMC Medicine 2015 13:189   doi:10.1186/s12916-015-0430-4