Elangovan Satheesh, Allareddy Veerasathpurush
Department of Periodontics, College of Dentistry, The University of Iowa, Iowa City, IA 52242, USA.
Department of Orthodontics, College of Dentistry, The University of Iowa, Iowa City, IA 52242, USA.
J Evid Based Dent Pract. 2015 Sep;15(3):97-104. doi: 10.1016/j.jebdp.2014.12.006. Epub 2015 Jul 18.
The objectives of the present study are to examine the publication metrics of dental journals and to delineate the role of self citations in determining the impact factor of journals.
The Journal Citation Reports database was used. All dental journals that had an impact factor assigned for year 2013 were selected. The outcomes were Impact Factor (IF), Eigenfactor™ (EF), article influence score (AIS), and proportion of self-citations to total citations. Independent variables were geographic region of journal and ranking of journal (based on IF). Non-parametric tests were used to examine the associations between outcomes and independent variables.
During the year 2013, 82 journals in dentistry had an IF. Mean IF was 1.489 and mean IF without including self-citations was 1.231. Mean EF scores and AIS were .00458 and .5141 respectively. Mean percentage of self cites to total citations for all dental journals was 12.24%. Higher ranking journals were associated with significantly higher EF and AIS. Journals published in USA/Canada or Europe were associated with higher IF and EF compared to those published in other regions. There were no differences in percentages of self citations to total citations either across journal rankings or geographic region.
Top ranking journals tend to have higher IFs due to higher EF and AIS rather than by self-citations. Self-citations increase the impact factors of dental journals by 21%. There was no geographic influence in the percentage of self-citations to total citations thus indicating a healthy dental scientific publishing environment.
本研究旨在考察牙科期刊的出版指标，并阐述自引在确定期刊影响因子中的作用。
使用《期刊引用报告》数据库。选取了所有在2013年被赋予影响因子的牙科期刊。结果指标为影响因子（IF）、特征因子（EF）、文章影响力得分（AIS）以及自引占总引用的比例。自变量为期刊的地理区域和期刊排名（基于影响因子）。采用非参数检验来考察结果指标与自变量之间的关联。
在2013年，82种牙科期刊有影响因子。平均影响因子为1.489，不包括自引的平均影响因子为1.231。平均特征因子得分和文章影响力得分分别为0.00458和0.5141。所有牙科期刊自引占总引用的平均百分比为12.24%。排名较高的期刊与显著更高的特征因子和文章影响力得分相关。与在其他地区出版的期刊相比，在美国/加拿大或欧洲出版的期刊具有更高的影响因子和特征因子。无论是在期刊排名还是地理区域方面，自引占总引用的百分比均无差异。
顶级期刊往往由于更高的特征因子和文章影响力得分而非自引而具有更高的影响因子。自引使牙科期刊的影响因子提高了21%。自引占总引用的百分比不存在地理影响，因此表明牙科科学出版环境健康。
