Table 1.
Examples of type I duplicates (duplicates among databases).
Table 2.
Examples of type II duplicates (duplicate publications).
Figure 1.
Study flowchart of finding duplicates in the literatures regarding portal vein thrombosis (panel A) and Budd-Chiari syndrome (panel B).
Table 3.
Characteristics of duplicates in literatures regarding portal vein thrombosis and Budd-Chiari syndrome.
Table 4.
Type I duplicates – difference between index and redundant papers.
Figure 2.
Proportion of wrong information of auto-searched (panel A) and hand-searched (panel B) type I duplicates from the literatures regarding portal vein thrombosis and that of auto-searched (panel C) and hand-searched (panel D) type I duplicates from literatures regarding Budd-Chiari syndrome.
Figure 3.
Simplified scheme to identify duplicates in systematic review.
The scheme includes the third main steps. First, all literatures retrieved from different databases are combined into one Endnote library. In this Endnote library, “Find Duplicates” preferences are defined on “Edit” menu. Thus, duplicates can be automatically searched by Endnote library. Subsequently, the review authors should check the accuracy and identify the type of duplicates. Finally, the redundant papers are excluded. Considering that a single strategy of auto-searching method was inadequate, additional search should be very necessary. Second, the remaining literatures are alphabetically ordered according to the first authors’ names in the Endnote library. If the first authors were the same between two or more articles, the review authors would further read the titles, journals’ names, volumes, issues, and pages. Subsequently, if these articles had the same titles, journals’ names, and issues, they would be attributed to the type I duplicates. Notably, the review authors should identify whether the difference between index and redundant papers was acceptable or not. On the other hand, if these had the same or similar titles but different journals or issues, the review authors would further read the abstracts and/or full-texts to judge whether or not they could be attributed to the type II duplicates. Third, the remaining literatures were also alphabetically ordered according to the titles in the Endnote library. If the titles were the same between two or more articles, the review authors would further read the journals’ names, volumes, issues, and pages. Subsequently, if these articles had the same journals’ names and issues, they would be attributed to type I duplicates. Notably, the review authors should identify whether the difference between index and redundant papers was acceptable or not. On the other hand, if these articles had the same or similar titles but different journals or issues, the review authors would further read the abstracts and/or full-texts to judge whether or not they could be attributed to the type II duplicates. Finally, review authors should check the accuracy.