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.
The receiver operating characteristic (ROC) curves of urine cotinine for determining the cutoff value used to distinguish non-exposure groups from passive smoking exposure groups. (A) The curve represents the male group and (B) the curve represents the female group.
