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.
PRISMA 2009 Flow Diagram (from Mober D, Liberti A, Tetzlaff J, and Altman DG; The PRISMA Group (2009). PreFigure 6. e 1000097 (access until 31 August 2021). For more information, visit WWW.prisma-Statement.org (access until 31 August 2021). Other sources appear as indicated.
