Funding for this research was provided by:
Chungnam National University (2018-0543-01)
Chungnam National University Hospital
National Research Foundation of Korea (2015R1A1A1A05001342)
Article History
Received: 17 March 2019
Accepted: 18 June 2019
First Online: 2 July 2019
Compliance with ethical standards
: The study was approved by the institutional review board of the participating hospital (approval number 4-2017-0637 and 201710-SB-045-01) and all participants provided informed consent. The study was conducted in accordance with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.
: The authors declare that they have no conflicts of interest.