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.
Abbreviation: PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-analyses.
aNot available in English: Jommi 201327; review: Khaykin 2012,28 Jones 2014,29 Kreidieh 201630; no cost per clinical effect: Panikker 2016.31
Source: Adapted from Moher et al.14
