Self-citation: comparison between Radiología, European Radiology and Radiology for 1997-1998.

Self-citation, considered as the number of times a paper cites other papers in the same journal, is an important criteria of journal quality. Our objective is to evaluate the self-citation in the official journal of the Spanish Society of Radiology (Radiología), and to compare it with the European Radiology and Radiology journals. Papers published in Radiología, European Radiology, and Radiology during 1997 and 1998 were analyzed. The Self Citation Index, considered as the ratio between self-references and total number of references per article, for the journals Radiología (SCIR), European Radiology (SCIER), and Radiology (SCIRY), were obtained and expressed as percentages. Also, the number of references to Radiología in European Radiology and Radiology papers were calculated. Stratification of the index per thematic area and article type was also performed. Mean SCIR, SCIER, and SCIRY values were compared with the ANOVA and the Student-Newman-Keuls tests. The self-citation index was statistically higher in Radiology (23.2%; p<0.0001) than in Radiología (1.8%) and European Radiology (0.8%). There were no statistically significant differences between SCIR and SCIER indexes ( p=0.25). In the stratification per thematic areas and article type, self-citation in Radiology was statistically higher ( p<0.0001), with the only exception of "Radioprotection" area ( p=0.2), to SCIR and SCIER. Although there were no statistically significant differences, by thematic areas SCIR was always larger than SCIER, with the only exception of the "Genitourinary imaging" area, and by article type SCIR also went greater to SCIER, except in review articles. Radiología, The Spanish official radiological journal, although not included in Index Medicus and its database Medline, had a larger number of self-citing than European Radiology in the period 1997-1998.