FIGURE 1.
Flow diagram of papers selected. * Search strategy limited to December 2019, English language, human subjects older than 13 years old
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.