Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

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.

View full-text article in PMC

. 2015 Aug 7;10:1571–1582. doi: 10.2147/COPD.S85767

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2015 Park et al. This work is published by Dove Medical Press Limited, and licensed under Creative Commons Attribution – Non Commercial (unported, v3.0) License

The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed.

PMC Copyright notice

Flowchart for selection of study subjects.

Notes: Normal pattern = FEV₁/FVC ≥70% and FEV₁ ≥80% predicted; restrictive pattern = FEV₁/FVC ≥70% and FEV₁ <80% predicted; obstructive pattern = FEV₁/FVC <70%.

Abbreviations: KNHANES, Korean National Health and Nutrition Examination Survey; PFT, pulmonary function test; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity.