A meta-analysis was carried out with Stata 11.0 software.



Stata
Databases, such as PubMed, Web of Science, CNKI, WanFang and VIP, were searched to collect randomized, controlled trials. 
PubMed
Databases, such as PubMed, Web of Science, CNKI, WanFang and VIP, were searched to collect randomized, controlled trials. 
Web of Science
Databases, such as PubMed, Web of Science, CNKI, WanFang and VIP, were searched to collect randomized, controlled trials. 
CNKI
Databases, such as PubMed, Web of Science, CNKI, WanFang and VIP, were searched to collect randomized, controlled trials. 
WanFang
Databases, such as PubMed, Web of Science, CNKI, WanFang and VIP, were searched to collect randomized, controlled trials. 
VIP