Background: Approximately 60% of randomized controlled trial (RCT) results presented at society meetings and published as abstracts in conference proceedings are eventually published in full in peer reviewed journals [1]. Accordingly, it is important to handsearch conference proceedings of important society meetings to find reports of unpublished RCTs. The annual meeting of the Association for Research in Vision and Ophthalmology (ARVO) is one of the most important sources of reports of RCTs and controlled clinical trials (CCTs) in the field of vision. Typically, ARVO accepts over 5,000 abstracts each year, but the proportion of identified RCTs and CCTs to total abstracts using handsearch tends to be low, for example, only 214 of 5,061 abstracts published in the ARVO conference book from 2001 were reports of RCTs and CCTs. Starting in the year 2002, ARVO no longer routinely distributes abstracts in a printed program, but instead places all abstracts accepted for presentation for the conference that year online and distributes a CD-ROM to conferences attendees, potentially increasing the difficulty of identifying clinical trials.
Objectives: To examine methods to identify reports of RCTs and CCTs published in conference proceedings. Methods: In April 2003, we approached the ARVO conference organizers to discuss the inclusion of a check-off box for abstract authors to indicate whether the abstract being submitted described the results of an RCT or CCT.

Results: In collaboration with the conference organizers, we included the following question and definition in the abstract submission form for 2004: Is the research presented in your abstract a human clinical trial? [Yes] [No] (see definition) Human Clinical Trial: A planned study in humans designed to assess the efficacy and/or safety of one or more test interventions by comparing outcomes in individuals assigned the test intervention(s) with those receiving no intervention or a comparison intervention, and where individuals in all groups are enrolled, treated, and followed concurrently. 634 of a total of 5,610 abstracts in which the authors had responded positively were identified by ARVO staff. These abstracts will be reviewed by the Cochrane Eyes and Vision Handsearching Unit to identify the validity of the classification, as well as the sensitivity and precision of the check box (author identification of study design) compared to electronic searching of the text and abstract alone.

Conclusions: Inclusion of an author self-classification box at submission of an abstract for a conference proceedings is a promising method to identify conference reports of RCTs and CCTs.

References: 1. Scherer RW, Langenberg P Full publication of results initially presented in abstracts (Cochrane Methodology Review). In: The Cochrane Library, Issue 2, 2004. Chichester, UK: John Wiley & Sons, Ltd.