Citation analysis of identical consensus statements revealed journal-related bias
Accepted 30 September 2009. published online 25 January 2010.
Abstract
Objective
To examine whether the prestige of a journal, measured by its impact factor, influences the numbers of citations obtained by published articles, independently of their scientific merit.
Study Design and Setting
In this cohort study, citation counts were retrieved for articles describing consensus statements that were published in multiple journals and were correlated with the impact factors of the source journals.
Results
Four consensus statements were published in multiple copies: QUOROM (QUality Of Reporting Of Meta-analyses) was published in three journals, CONSORT (CONsolidated Standards Of Reporting Trials) in eight journals, STARD (STAndards for Reporting of Diagnostic accuracy) in 14 journals, and STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) in eight journals. For each consensus statement, the impact factor of the source journal and the number of citations were highly correlated (Spearman correlation coefficients: QUOROM, 1.00; CONSORT, 0.88; STARD, 0.65; and STROBE, 0.81—all P<0.02). When adjusted for time since publication, each logarithm unit of impact factor predicted an increase of 1.0 logarithm unit of citations (95% confidence interval: 0.7–1.3, P<0.001), and the variance explained was 66% (adjusted r2=0.66).
Conclusions
The prominence of the journal where an article is published, measured by its impact factor, influences the number of citations that the article will gather over time. Citation counts are not purely a reflection of scientific merit.
Division of Clinical Epidemiology, University Hospitals of Geneva, Geneva, Switzerland
Corresponding author. Division of Clinical Epidemiology, University Hospitals of Geneva, 2 rue Gabrielle Perret-Gentil, CH-1211 Geneva, Switzerland. Tel.: +41-22-372-9037; fax: +41-22-372-9035.
Competing interests: The author has no conflict of interest related to this article.
Contributions: T.V.P. conceived the idea of the study, performed the data retrieval and analysis, interpreted the results, and wrote the article.
Funding: The study received no specific funding.
Data access: T.V.P. had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Ethics committee approval: Approval was not sought.
ABSTRACT