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.
Kaplan-Meier Analysis: Regional EC. Graph shows increasing survival from 1970's to 2000's with largest improvement in survival seen from the 1990's to 2000's. The p-values reported for trend analysis refers to comparison among all of the four decade quartiles.
