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.
A ratio is a score derived by dividing a count of one type of data by a count of another type of data. For example, the number of patients with central lines who develop infection divided by the number of central line days. The key to the definition of a ratio is the numerator is not in the denominator.