Background: Inappropriate authors' self-citation (A-SC) is a growing mal-practice possibly boosted by the raising importance given to author's metrics. Similarly, also excessive journals' self-citation (J-SC) practice may factitiously influence journal's metrics (impact factor, IF). Evaluating the appropriateness of each self-citation remains challenging.
Main body: We evaluated the presence of policies discouraging A-SC in Critical Care Medicine (CCM) journals with IF. We also calculated the J-SC rate of these journals. In order to evaluate if J-SC rates are influenced by the focus of interest of CCM journals, we separated them in three sub-categories ("multidisciplinary", "broad" or "topic-specific" CCM journals). We analyzed 35 CCM journals and only 5 (14.3%) discouraged excessive and inappropriate A-SC. The median IF was higher in CCM journals with A-SC policies [4.1 (3-12)] as compared to those without [2.5 (2-3.5); p = 0.02]. The J-SC rate was highly variable (0-35.4%), and not influenced by the presence of A-SC policies (p = 0.32). However, J-SC rate was different according to the focus of interest (p = 0.01): in particular, it was higher in "topic-specific" CCM journals [15.3 (8.8-23.3%)], followed by "broad" CCM [11.8 (4.8-17.9%)] and "multidisciplinary" journals [6.1 (3.6-9.1%)].
Conclusions: A limited number of CCM journals have policies for limiting A-SC, and these have higher IF. The J-SC rate among CCM journals is highly variable and higher in "topic-specific" interest CCM journals. Excluding self-referencing practice from scientific metrics calculation could be valuable to tackle this scientific malpractice.
Keywords: Authors; Citations; Impact factor; Intensive Care; Journals; Policies; Self-citations.