Figure 1.
The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) flow diagram identifies the total number of articles initially surveyed and the number of articles included and excluded for this systematic review.
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.