Figure 1.
Methodology PRISMA (Preferred Reporting Items for Systematic Evaluation and Meta-Analysis) Flow Chart. aA total of 255 studies from PubMed, 624 from Embase, 253 from the Cochrane Library, 28 from Web of Science, 23 from CNKI, 88 from CSTJ, 26 from Wan fang database, and 5 from CBM