title: Association between study design and citation counts of articles published in the American Journal of Orthodontics and Dentofacial Orthopedics and Angle Orthodontist.
abstract: OBJECTIVE
  The scientific community views meta-analyses and systematic reviews, in addition to well-designed randomized controlled clinical trials, as the highest echelon in the continuum of hierarchy of evidence. The objective of this study was to examine the association between different study designs and citation counts of articles published in the American Journal of Orthodontics and Dentofacial Orthopedics and Angle Orthodontist.
  
  
  METHODS
  All articles, excluding editorial comments, letters to the editor, commentaries, and special articles, that were published in the American Journal of Orthodontics and Dentofacial Orthopedics and Angle Orthodontist during the years 2004 and 2005 were examined in this study. The number of times an article was cited in the first 24 months after its publication was computed. The PubMed database was used to index the study design of the articles. The association between study design and citation counts was examined using the Kruskal-Wallis test. A multivariable negative binomial regression model was used to examine the association between citation count and study design along with several other confounding variables.
  
  
  RESULTS
  A total of 624 articles were selected for analysis. Of these, there were 25 meta-analyses or review articles, 42 randomized clinical trials, 59 clinical trials, 48 animal studies, 64 case reports, and 386 quasiexperimental/miscellaneous study designs. The mean ± SD citation count was 1.04 ± 1.46. Nearly half of the articles (n = 311) were not cited even once during the observation period. Case reports were cited less frequently than meta-analyses or reviews (incident risk ratio, 0.37; 95% confidence interval, 0.19 to 0.72; P = .003), even after adjusting for other independent variables.
  
  
  CONCLUSIONS
  Among various study designs, meta-analyses and review articles are more likely to be cited in the first 24 months after publication. This study demonstrates the importance of publishing more meta-analyses and review articles for quicker dissemination of research findings.
authors.affiliation: Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts 02215, USA. VA15@hsdm.harvard.edu
authors.forename: Veerasathpurush
authors.initials: V
authors.lastname: Allareddy
authors.forename: Min Kyeong
authors.initials: MK
authors.lastname: Lee
authors.forename: Andrea
authors.initials: A
authors.lastname: Shah
authors.forename: Satheesh
authors.initials: S
authors.lastname: Elangovan
authors.forename: Chin-Yu
authors.initials: CY
authors.lastname: Lin
mesh_terms: D015706:Bibliometrics; D006801:Humans; D009970:Orthodontics; D000066792:Orthodontists; D009985:Orthopedics; D010506:Periodicals as Topic; D011642:Publications; D011643:Publishing; D012107:Research Design; D014481:United States