FIGURE 1.
PRISMA flow diagram shows the number of articles searched and excluded at each stage of the literature search after screening titles, abstracts, and full texts.
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.