How has the dental literature evolved over time? Analyzing 20 years of journal self-citation rates and impact factors

Abstract

Objective: As journal impact factors (IFs) can be artificially inflated by excessive journal self-citation practices, research quality evaluation based solely on IF ranking may be manipulated and, therefore, ethically challenged. This study aimed to analyze the longitudinal development of journal self-citation rates (SCRs) and IFs in dental literature and to determine possible confounders. Methods: Twenty-eight journals with scope within general dentistry and (sub)specialties listed in 1997-2016 Journal of Citation Reports V R were scrutinized. The following information was retrieved: publication year, total number of citations, number of self-citations, IF, corrected IF, and SCR. Results: Endodontic journals had the highest SCR (median ¼ 35.3, IQR ¼ 21.6-47.5), journals related to periodontics had the lowest (median ¼ 14.7, IQR ¼ 8.9-25.5). Periodontics had the highest IF (median ¼ 2.1, IQR¼ 1.7-2.8) and general dentistry had the lowest (median ¼ 0.9, IQR ¼ 0.7-1.2). SCR significantly decreased over time (p < .0001) by 1 unit per year. Additionally, 1 unit increase in corrected IF resulted in 15.2 units decrease in SCR. IFs significantly increased 0.06 units per year (p < .000). Conclusions: Overall, favourable changes in citation metrics have been observed for dental journals during the 20-year observation period. SCR significantly decreased per observation year whereas IFs significantly increased, indicating a healthy publishing environment in the dental literature. SCR was regulated both by time and corrected IF.

Factors, components and dynamics: investigation of journal self-citation and citation by equal opportunity model

“…Recent emerging studies indicated the relations between citation and self-citation were usually diversified dependent on what disciplines and/or journals were concerned ( Krauss, 2007 ; Gazni and Didegah, 2021 ; Jain et al., 2021 ; Jamalnia and Shokrpour, 2021 ; Kulczycki et al., 2021 ; Urlings et al., 2021 ; Sanfilippo et al., 2021 ). In addition, longitudinal studies in medical literature showed a decline in the JSC rate in terms of total citations ( Delli and Livas, 2018 ; Delli et al., 2020 ), the accustomed indicator of JSC at present. In contrast, the JSC rate in terms of citable items increased significantly and had a significant relationship with the total citations ( Chorus and Waltman, 2016 ).…”

Citations and Gamed Metrics: Academic Integrity Lost

“…There is also an unethical component because they are, or may be perceived to be, unfair and because excessive self-citation rates-for example, 40-67 percent in twenty-eight dental journals indexed in Clarivate Analytics' Journal of Citation Reports (JCR) from 1997-2016, 20 or ranging massively between 4-54 percent in ten plastic surgery journals indexed in JCR from 2009-2015-can bloat JIFs and the perception of a journal's importance. 21 In June of 2020, due to excessive self-citation, JCR suppressed the JIFs of several journals and issued editorial expressions of concern for several other journals, 22 highlighting the risks that journals take when they employ JBMs as a performance rating.…”