Funding for this research was provided by:
Text and Data Mining valid from 2020-01-11
Received: 17 September 2019
Accepted: 29 November 2019
First Online: 11 January 2020
Ethics approval and consent to participate
: This study used an existing database, which was anonymized, with subjects’ details untraceable during analysis. Consequently, no informed consent or data monitoring process was required for this study. This study was reviewed by the institutional review board (IRB) at Seoul National University Bundang Hospital, and IRB-approved as exempt (IRB number: X-1801-447-903).
: No informed consent or data monitoring process was required for this study.
: Ye Seul Yang, Bo Ram Yang and Mi-Sook Kim have no conflicts of interest directly relevant to the content of this article. Sung Hee Choi received research funding from Amgen (Amgen study number: 20170708) and Yunji Hwang is employed by Amgen.