title: What Effect Does Self-Citation Have on Bibliometric Measures in Academic Plastic Surgery?
abstract: BACKGROUND
  Research productivity plays a significant role in academic promotions. Currently, various bibliometric measures utilizing citation counts are used to judge an author's work. With increasing numbers of journals, numbers of open access publications, ease of online submission, and expedited indexing of accepted manuscripts, it is plausible that an author could influence his/her own bibliometric measures through self-citation. The purpose of this study was to determine the impact of self-citation in academic plastic surgery.
  
  
  METHODS
  A cohort of full-time academic plastic surgeons was identified from 9 U.S. plastic surgery training programs. For all included faculty, academic rank was retrieved from department/division websites, and bibliometric measures were assessed using a subscription bibliographic citation database (Scopus, Reed Elsevier, London, UK). Bibliometric measures included the Hirsch index (h-index, the number of publications h which are cited ≥ h times), total number of publications, and total number of citations. The h-index and total number of citations were collected with and without self-citations. Percent changes in the h-index and total citations were calculated after removal of self-citations and compared across academic ranks and levels of research productivity (total publications, h-index, and total citations).
  
  
  RESULTS
  The study cohort consisted of 169 full-time academic plastic surgeons. The h-index and total citations experienced decreases of 2.8 ± 5.0% (P < 0.0001) and 4.5 ± 4.6% (P < 0.0001), respectively, after correction for self-citation. More than half of the cohort (n = 113, 67%) did not experience a change in the h-index after removal of self-citations. These decreases did not vary across academic rank. Surgeons who self-cited at rates greater than 5% were 9.8 times more likely (95% confidence interval, 4.5-21.9; P < 0.001) to have their h-index change as a result of self-citation (after adjusting for academic rank). There were weak correlations between percent decreases in the h-index and total citations and various biblimoteric measures (total publications, h-index, total citations; r < 0.32).
  
  
  CONCLUSIONS
  Self-citation has a minor impact on common bibliometric measures in academic plastic surgery. The influence of self-citation is consistent across academic ranks and increasing levels of bibliometric measures, suggesting that authors are not manipulating the system with increasing experience.
authors.affiliation: From the *Department of Plastic and Reconstructive Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD; and †Division of Plastic and Reconstructive Surgery, Department of Surgery, Massachusetts General Hospital, Boston, MA.
authors.forename: Edward W
authors.initials: EW
authors.lastname: Swanson
authors.forename: Devin T
authors.initials: DT
authors.lastname: Miller
authors.forename: Srinivas M
authors.initials: SM
authors.lastname: Susarla
authors.forename: Joseph
authors.initials: J
authors.lastname: Lopez
authors.forename: Denver M
authors.initials: DM
authors.lastname: Lough
authors.forename: James W
authors.initials: JW
authors.lastname: May
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Redett
mesh_terms: D015706:Bibliometrics; D005180:Faculty, Medical / Q000706:statistics & numerical data*; D006801:Humans; D011643:Publishing / Q000706:statistics & numerical data*; D066231:Surgeons / Q000706:statistics & numerical data*; D013518:Surgery, Plastic; D014481:United States