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.
Squares represent mean values with 95% CIs, with the size of the squares indicating weight. The diamond represents the pooled mean with the points of the diamond representing 95% CI.
