Update on the endorsement of CONSORT by high impact factor journals: a survey of journal "Instructions to Authors" in 2014.

BACKGROUND: The CONsolidated Standards Of Reporting Trials (CONSORT) Statement provides a minimum standard set of items to be reported in published clinical trials; it has received widespread recognition within the biomedical publishing community. This research aims to provide an update on the endorsement of CONSORT by high impact medical journals.

METHODS: We performed a cross-sectional examination of the online "Instructions to Authors" of 168 high impact factor (2012) biomedical journals between July and December 2014. We assessed whether the text of the "Instructions to Authors" mentioned the CONSORT Statement and any CONSORT extensions, and we quantified the extent and nature of the journals' endorsements of these. These data were described by frequencies. We also determined whether journals mentioned trial registration and the International Committee of Medical Journal Editors (ICMJE; other than in regards to trial registration) and whether either of these was associated with CONSORT endorsement (relative risk and 95 % confidence interval). We compared our findings to the two previous iterations of this survey (in 2003 and 2007). We also identified the publishers of the included journals.

RESULTS: Sixty-three percent (106/168) of the included journals mentioned CONSORT in their "Instructions to Authors." Forty-four endorsers (42 %) explicitly stated that authors "must" use CONSORT to prepare their trial manuscript, 38 % required an accompanying completed CONSORT checklist as a condition of submission, and 39 % explicitly requested the inclusion of a flow diagram with the submission. CONSORT extensions were endorsed by very few journals. One hundred and thirty journals (77 %) mentioned ICMJE, and 106 (63 %) mentioned trial registration.

CONCLUSIONS: The endorsement of CONSORT by high impact journals has increased over time; however, specific instructions on how CONSORT should be used by authors are inconsistent across journals and publishers. Publishers and journals should encourage authors to use CONSORT and set clear expectations for authors about compliance with CONSORT.