Fig. 1. Flowchart for literature search and study selection process [19].
Study selection flow diagram of meta-analyses providing quantitative data. Three meta-analyses were manually identified.
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.