[Comparison of instructions to authors of Mexican medical journals and the Vancouver requirements].

OBJECTIVE: To find out how much information of the Vancouver norms (VANNOR) are given to prospective authors in the instructions for authors (IFA) in some Mexican medical journals (MMJ).

DESIGN: Prospective, cross sectional, descriptive, observational.

MEASUREMENTS: To score the IFA in the MMJ published between 1989 and 1991. The scoring was done on the basis of presence in the IFA of the VANNOR characteristics grouped in categories (characteristics and presentation of the manuscript, title page, summary and keywords, text order and contents, references, tables, illustrations, and other instructions). A total score of 60 characteristics (grouped in nine categories) was obtained for each journal. Statistical differences as a function of VANNOR affiliation were investigated by means of Student's t test, chi-square, and exact Fisher tests using a 0.05 alpha level (two-tailed).

RESULTS: 50 MMJ were included (21 affiliated to VANNOR). No statistical difference was found for VANNOR affiliation and registration in bibliographic data bases. But statistically significant higher scores were found in the affiliated journals in 12 of 60 characteristics (three of nine categories) and in the total score.

CONCLUSIONS: Independently of VANNOR affiliation, there were deficiencies in the IFA of all journals, particularly in instructions regarding the manuscript's contents. Possibly, some inadequacies in manuscripts might be prevented with IFA that comply more thoroughly with the VANNOR requirements.