Background: Whether the journal impact factor (JIF) indicator reflects the number of citations to an average article of a journal in different subject categories is controversial. We sought to further investigate this issue in general and internal medicine journals.
Methods: We selected to evaluate three journals of the above subject category, in each of three different JIF levels (high: 15.5-28.6, moderate: 4.4-4.9 and low: 1.6). Using the Scopus database, we retrieved the original research articles (after detailed screening) and review articles (as classified by Scopus) that were published in the selected journals in 2005 along with the number of citations they received in 2006 and 2007. We pooled the citations for articles of the same type in journals with the same JIF level into distinct variables.
Results: There was no marked association between the distribution of citations per article published in general medical journals and their JIF. All distributions studied were skewed to the right (higher number of citations). Specifically, 16-22% of the original research articles accounted for 50% of the total citations to this type of article for all three categories of studied journals; 34-37% of original research articles accounted for 75% of citations. The respective values for review articles were 12-18% and 29-39%.
Conclusion: The distribution of citations received by articles published in high, moderate and low impact factor journals in clinical medicine seems similar. The JIF is not an accurate indicator of the citations the average article receives; articles published in low impact factor journals can still be highly cited and vice versa.