Methods: We searched Web of Science, Embase, PubMed, and Cochrane Library databases. 
Web of Science
Methods: We searched Web of Science, Embase, PubMed, and Cochrane Library databases. 
Embase
Methods: We searched Web of Science, Embase, PubMed, and Cochrane Library databases. 
PubMed
Methods: We searched Web of Science, Embase, PubMed, and Cochrane Library databases. 
Cochrane Library databases
Review Manager 5.3 and Stata 12.0 were used for meta-, sensitivity, and bias analysis. 
Review Manager 5.3
Review Manager 5.3 and Stata 12.0 were used for meta-, sensitivity, and bias analysis. 
Stata 12.0