Pre-publication abstract-only reports compared to full-text manuscripts for randomised controlled trials in inflammatory bowel disease: a systematic review

Abstract

Introduction: RCTs of key therapies in IBD are often presented and available as abstracts for significant periods of time prior to full publication, often being employed to make strategic and clinical prescribing decisions. We compared the concordance of pre-publication abstract-only reports and their respective full-text manuscripts.
Methods: Pairs of full-text manuscripts and their respective pre-publication abstract-only reports for the same RCT outcomes, at the same timepoint of analysis were included. The RCTs were on treatments for IBD with full-text manuscripts published between 2010-2023.
Results: We found 77 pairs of full-text manuscripts and their pre-publication abstract-only reports. There were significant mis-matches in the reporting of; stated planned outcomes (65/77 matched, p<0.001), and primary outcomes reported in their results sections (67/77, p<0.001); trial registrations (34/65, p<0.001); numbers of randomised participants (49/77, p=0.18); participants reaching end of study (21/71, p<0.001); and primary outcome data (40/73, p<0.001). Authors conclusions matched (75/77, p=0.157). Authors did not provide explicit or implied justifications for the absence or non-concordance for any of the above items.
Conclusions: Abstract-only reports have consistent issues with both limited reporting of key information and significant differences in data when compared with their later full-text publications. These are not related to further recruitment of patients or word count limitations, and are never explained. As abstracts are often used in guidelines, reviews and stakeholder decision making on prescribing, caution in their use is strongly suggested. Further work is needed to enhance minimum reporting standards in abstract-only works and ensure consistency with final published papers.
What is already known on this topic – Data from abstract-only reports of RCTs are often used as evidence sources for clinical and strategic decision-making in IBD. It is not known whether they are up to par for this purpose. What this study adds – Our findings suggest that abstract-only reports are often inconsistent in their reporting, compared with their respective full-text manuscripts, especially in areas such as flow of participants and primary outcome data. These are not related to further recruitment of patients or word count limitations, and are never explained. How this study might affect research, practice or policy – Caution is advised when abstract-only reports are used as evidence sources. Enhanced minimum reporting standards for abstract-only reports need to be employed