Figure 2.
Risk of bias assessment. (A) Authors’ judgments about risk of bias graph for each included study; (B) Authors’ judgments about risk of bias summary across all included studies.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.