Funding for this research was provided by:
National Research Foundation of Korea (2012R1A1A1010107, 2015R1A1A1A05001342)
Chungnam National University (2016-1793-01)
Ministry of Health and Welfare (1520190)
Article History
Received: 16 October 2017
Accepted: 8 August 2018
First Online: 17 August 2018
Compliance with ethical standards
: The study was approved by the institutional review board of the participating hospital (approval number: 4-2014-0700). Participants received detailed information regarding the purpose and details of the study from research nurses. Informed consent was obtained from those who agreed to participate.
: The authors declare that they have no conflicts of interest.