Figure 2.
Risk of bias summary: review authors' judgements about each risk of bias item for each included study. Please note that Luo 2004 and Wu 1996 were quasi‐randomised studies and were included in the adverse events review only.
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.