[Errors in bibliographic references: a retrospective study in Medicina Clinica (1962-1992)]

Misspellings of transcription or the copy of references of articles published in the literature without verifying the information with the original document may be the cause of incorrect citations. The purpose of this study was to determine the accuracy of citations to journal articles in 1962 to 1992 volumes of Medicina Clínica.

A method of systematic sampling was used to choose five references for each of the 12 original articles per year selected at 5-year intervals (1962, 1967, 1972, 1977, 1982, 1987, 1992). In the final sample of 420 references, errors in the six standard bibliographic elements--authors' names, article title, journal title, year, volume number, and page numbers--were analyzed. Major errors were defined when inaccuracies prevented identification of the cited article.

Of the total 368 references verified, 132 (35.86%) were error free and the remaining 236 (64, 13%) were inaccurate. Multiple errors were found in 45% of cases. The mean number of errors per references was 1.13. Twelve references were incorrect, 221 errors were found in the authors' name, 131 in the title of the article, 14 in the name of the journal, 5 in the year of publication, 12 in the number of the volume, and 22 in the initial or final pages of the article. Major errors were detected in 94 (22.54%) cases and minor errors in 323 (77.45%). There were no statistically significant differences in the variation of the overall percentage of errors throughout the study period.

A high rate of citation errors has been also documented in a Spanish medical journal. The importance of reference verification should be emphasized and authors should exercise more care in preparing bibliographies of their articles.