title: [Is impact factor an appropriate index to determine the level of evidence of studies on therapeutic procedures in surgery journals?].
abstract: BACKGROUND
  The aim of this study was to determine the association between the IF of surgery journals and the level of evidence of articles on therapeutic procedures published in these journals.
  
  
  METHODS
  A bibliometric study was performed. Journals listed in the 2002 ISI under the subject heading of Surgery were included. Journals were classified by applying the 33rd percentile of their IF (group 1 from 0.128 to 1.690, group 2 from 1.691 to 2.886, and group 3 from 2.887 to 6.674). Simple randomized sampling was conducted of journals in each group (group 1: Eur J Surg, Am Surg and World J Surg; group 2: J Am Coll Surg, Surgery and Arch Surg; and group 3: Br J Surg and Ann Surg). A crossover analysis was performed by 2 independent teams of reviewers.
  
  
  RESULTS
  There were 751 article on therapy (41.2%). The mean IF was 1.66 +/- 0.48 for group 1, 2.61 +/- 0.15 for group 2, and 4.69 +/- 1.57 for group 3 (P<.001). There were 16 systematic reviews, 82 randomized clinical trials, 96 cohort studies, 474 case series and 79 review articles. Level 1 evidence was found in only 4.8% of the articles. Statistical differences were verified in 15.1% of the study sample, which was represented by systematic reviews and randomized clinical trials (most frequent in group 3 (P<.001).
  
  
  CONCLUSIONS
  An association between the IF of scientific surgical journals and the level of evidence in articles published on therapy was verified.
authors.affiliation: Departamento de Cirugía, Universidad de la Frontera, Temuco, Chile. cmantero@ufro.cl
authors.forename: Carlos
authors.initials: C
authors.lastname: Manterola
authors.forename: Viviana
authors.initials: V
authors.lastname: Pineda
authors.forename: Manuel
authors.initials: M
authors.lastname: Vial
authors.forename: Héctor
authors.initials: H
authors.lastname: Losada
mesh_terms: D015706:Bibliometrics; D019317:Evidence-Based Medicine; D013502:General Surgery; D010506:Periodicals as Topic; D011643:Publishing / Q000592:standards* / Q000706:statistics & numerical data*; D013514:Surgical Procedures, Operative