Fig. 1.
Comparison of the number of subjects with airflow limitation of all age groups.
Fixed ratio (+), observed FEV1/FVC <0.7; LLN (+), observed FEV1/FVC <LLN.
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.