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 point estimates, with the marker size indicating weight; horizontal lines represent 95% CIs. Diamonds represent the pooled point estimate, with the points indicating the 95% CI.
