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.
Percentages reflect involvement of a particular level with respect to the total number of patients. And percentages add up to greater than 100% because multiple levels were often involved in the same patient.
