Fig. 1.
Prisma flow chart. CENTRAL, Cochrane Central Register of Controlled Trials; CINAHL, Cumulated Index in Nursing and Allied Health Literature; n, number of studies.
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.