. 2018 Aug 24;6(8):e10502. doi: 10.2196/10502
©Hee Kwon, Sungin Lee, Eun Ji Jung, SangHee Kim, Jung-Kyu Lee, Deog Kyeom Kim, Tae-Hyung Kim, Seung Hyeun Lee, Myoung Kyu Lee, Seungjae Song, Kichul Shin. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 24.08.2018.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in JMIR mhealth and uhealth, is properly cited. The complete bibliographic information, a link to the original publication on http://mhealth.jmir.org/, as well as this copyright and license information must be included.
Figure 1.
Study design. COPD: Chronic obstructive pulmonary disease; SMG-SNU: Seoul Metropolitan Government-Seoul National University.