Full publication of results initially presented in abstracts. A meta-analysis.

OBJECTIVES

To estimate the rate of full publication of the results of randomized clinical trials initially presented as abstracts at national ophthalmology meetings in 1988 and 1989; and to combine data from this study with data from similar studies to determine the rate at which abstracts are subsequently published in full and the association between selected study characteristics and full publication.

DATA SOURCES

Ophthalmology abstracts were identified by review of 1988 and 1989 meeting abstracts for the Association for Research in Vision and Ophthalmology and the American Academy of Ophthalmology. Similar studies were identified either from reports contained in our files or through a MEDLINE search, which combined the textword "abstract" with "or" statements to the Medical Subject Headings ABSTRACTING & INDEXING, CLINICAL TRIALS, PEER REVIEW, PERIODICALS, MEDICAL SOCIETIES, PUBLISHING, MEDLINE, INFORMATION SERVICES, and REGISTRIES.

STUDY SELECTION

Ophthalmology abstracts were selected from the meeting proceedings if they reported results from a randomized controlled trial. For the summary study, similar studies were eligible for inclusion if they described followup and subsequent full publication for a cohort of abstracts describing the results of any type of research study. All studies had to have followed up abstracts for at least 24 months to be included.

DATA EXTRACTION

Authors of ophthalmology abstracts were contacted by letter to ascertain whether there was subsequent full publication. Other information, including characteristics of the study design possibly related to publication, was taken from the abstract. For the summary study, rates of full publication were taken directly from reported results, as were associations between study factors (ie, "significant" results and sample size) and full publication.

DATA SYNTHESIS

Sixty-six percent (61/93) of ophthalmology abstracts were published in full. Combined results from 11 studies showed that 51% (1198/2391) of all abstracts were subsequently published in full. Full publication was weakly associated with "significant" results and sample size above the median.

CONCLUSIONS

Approximately one half of all studies initially presented in abstract form are subsequently published as full-length reports. Most are published in full within 2 years of appearance as abstracts. Full publication may be associated with "significant" results and sample size.