"Eigenlob": self-citation in biomedical journals.

The number of citations to previous work of an individual scientist has been considered, in part, to be an important indicator of academic performance in research. Some of these citations, of course, are to the author’s own work; the Germans call this “Eigenlob,” or self-praise. We analyzed data obtained from 340 papers (294 original articles and 46 review papers) in a sample of leading biomedical science journals published during the first two months of 2005. Seventeen and 20% of references of papers published in clinical and basic science journals, respectively, referred to previous work of the authors (self-citations). Nineteen and 11% of references of original articles and review papers, respectively, were self-citations. The proportion of references of the examined papers that were self-citations was higher for original articles than review papers (Odds Ratio (OR) 1.39, 95% Confidence Interval (CI) 1.21–1.61, P 0.001) and for papers published in nonclinical journals than in clinical journals (OR 1.36, 95% CI 1.23–1.51, P 0.001). In addition, the number of authors was also associated with the proportion of references that were self-citations (OR 1.03 per author, 95% CI 1.02–1.04, P 0.001). Self-citation was approximately equally divided between the first and the last author in papers of clinical journals while it mainly referred to the last author in papers of nonclinical journals.