2.4 Study selection
NoteExpress software was used for research screening. First, two researchers (J Jiang and ZG Wu) independently screened and checked the titles and abstracts of articles to exclude duplicate and irrelevant studies. Second, the full text of potentially eligible studies was downloaded and reviewed according to the inclusion and exclusion criteria stated above. Finally, when inconsistencies or disagreements arose, a third author (W Zhang) assisted in resolving the issue.