FIGURE 2.
Kaplan–Meier survival curves by a) Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2015 and b) GOLD 2019.
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.