Trusting Early Results Before Publication? Transition from Meetings to Journals

[Epidemiologic Inquiry 2006, 1: 20]

While doing a literature search, it is relatively common to find that either the results of a RCT presented at a scientific meeting were never published in a journal; or the results in the journal publication are discordant from those presented at the scientific meeting. Should we use the results from the scientific meeting, even if the results were never published later? Or should be just use the results from the peer-reviewed journal article, which might ensure completeness and proper interpretation of the data? This week's paper by Toma et al. in JAMA attempts to address these questions by examining the proportion of RCTs presented at American College of Cardiology (ACC) scientific meetings which were subsequently published as full-length journal articles; and the consistency between the data presented in the meeting abstract and the subsequent full-length publication.

The authors selected all RCTs presented at the scientific meetings of ACC between 1999 and 2002 and then searched the literature to see if these were ever published as full-length journal articles till the time of literature search. A distinction was made between the late- breaking clinical trials and the trials presented at other sessions of the ACC (oral or poster sessions). Significant results included the findings that the late-breaking clinical trials were more likely to be published as a full-length journal article subsequently (92% vs 69%); it was more likely that a design paper had been published prior to presentation of results for the late-breaking clinical trials (31% vs 13%); the late-breaking trials were likely to be larger (Median n=725 vs n=196); and the late-breaking trials were less likely to report a favorable effect of the intervention (OR of 0.46; 95% CI = 0.24, 0.90). The late-breaking trials also had higher quality scores and were more likely to be published in a journal with higher impact factor as compared to the RCTs presented at other sessions.

The authors believe that the differences between the late-breaking clinical trials and others can be explained to a certain extent by the process of selection of these RCTs. The application for presenting at the late-breaking session needs to be made at least 3 months in advance of the meeting and needs to be supported by details of the purpose, design, and methods of the trial. Also, since the results of these RCTs are not known at the time of application, it is more likely that they would report both favorable as well as negative results for the tested interventions.

Most importantly though, 41% of the RCTs (both late-breaking trials as well as others) which were subsequently published had a different estimate of primary outcome in the journal article as compared to what was presented at the scientific meetings. This suggests that we should not be over-eager in embracing the results from scientific meetings into clinical practice or in meta-analyses and we should wait for a peer-reviewed publication first. As the authors say - "As Shakespeare may have said in the 21st century, there are many slips betwixt podium and page".

~The Editors

Reference: Toma M, McAlister FA, Bialy L, Adams D, Vandermeer B, Armstrong PW. Transition From Meeting Abstract to Full-length Journal Article for Randomized Controlled Trials. JAMA 2006;295:1281-1287.