3.1 Data search results
The search flow results of our systematic review are described in the study selection process (Appendix S1). After removing 20 duplicate records, the titles and abstracts of 57 records were screened. We excluded 48 records by reading the abstracts, of which 16 studies included only one treatment group without a comparison group and 32 studies were reviews, commentaries and case reports. Of the 9 full-text articles assessed for eligibility, 2 were excluded for reporting overlapping data. Finally, 7 studies met the selection criteria and were included in the meta-analysis [12-14,21-24].