title: Assessment of publication bias in dental specialty journals.
abstract: OBJECTIVE
  The purpose of this study was to investigate the presence of publication bias (acceptance of articles indicating statistically significant results).
  
  
  METHODS
  The journals possessing the highest impact factor (2008 data) in each dental specialty were included in the study. The content of the 6 most recent issues of each journal was hand searched and research articles were classified into 4 type categories: cross-sectional, case-control, cohort, and interventional (nonrandomized clinical trials and randomized controlled trials). In total, 396 articles were included in the analysis. Descriptive statistics and univariate and multivariate logistic regression was used to examine the association between article-reported statistical significance (dependent variable) and journal impact factor and article study type subject area (independent variables).
  
  
  RESULTS
  A statistically significant acceptance rate of positive result was found, ranging from 75% to 90%, whereas the value of impact factor was not related to publication bias among leading dental journals. Compared with other research designs, clinical intervention studies (randomized or nonrandomized) presented the highest percentage of nonsignificant findings (20%); RCTs represented 6% of the examined investigations.
  
  
  CONCLUSIONS
  Compared with the Journal of Clinical Periodontology, all other subspecialty journals, except the Journal of Oral and Maxillofacial Surgery, showed significantly decreased odds of publishing an RCT, which ranged from 60% to 93% (P < .05).
authors.affiliation: Department of Community and Preventive Dentistry, University of Athens, Greece.
authors.forename: Argy
authors.initials: A
authors.lastname: Polychronopoulou
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Pandis
authors.forename: Theodore
authors.initials: T
authors.lastname: Eliades
mesh_terms: D055811:Journal Impact Factor; D010506:Periodicals as Topic / Q000706:statistics & numerical data*; D017594:Publication Bias; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D013039:Specialties, Dental