Figure 1.
Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) flow diagram of articles identification and selection. PPI, proton pump inhibitor.
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.