Two-thirds of methodological research remained unpublished after presentation at Cochrane Colloquia: an empirical analysis.
OBJECTIVE
To determine the extent to which abstracts of methodology research, initially presented at annual meetings of The Cochrane Collaboration, have been published as full reports and over what period of time. A secondary aim was to explore whether full publication varied in different methodological subject areas.


METHODS
The Cochrane Methodology Register (CMR) was searched for all abstracts reporting methodology research, presented at the 11 Cochrane Colloquia from 1997 to 2007. EMBASE, PubMed, and CMR were searched for full publications of the same research.


RESULTS
We identified 908 eligible conference abstracts and found full publications for 312 (34.4%) of these, almost half of which (47.1%) had appeared by the end of the first year after the relevant Colloquium. The proportion of abstracts that had not been published by 3 years was 69.7%, falling to 66.2% at 5 years. Publication varied considerably between different methodological areas.


CONCLUSIONS
Approximately two-thirds of methodological research studies presented at Cochrane Colloquia remain unpublished as full papers at least 5 years later. This highlights the importance of searching conference abstracts if one wishes to find as comprehensive and complete a sample of methodological research as possible.
UK Cochrane Centre, National Institute for Health Research, Summertown Pavilion, 18-24 Middle Way, Oxford OX2 7LG, UK. SChapman@cochrane.ac.uk
Sarah
S
Chapman
Anne
A
Eisinga
Sally
S
Hopewell
Mike
M
Clarke
D000043:Abstracting and Indexing; D003226:Congresses as Topic; D003299:Cooperative Behavior; D036262:Empirical Research; D006801:Humans; D033181:Information Dissemination; D009939:Organizations, Nonprofit; D017594:Publication Bias; D011643:Publishing / Q000706:statistics & numerical data*; D012107:Research Design; D012196:Review Literature as Topic; D013997:Time Factors