[1] Korea Univ, Ansan Hosp, Dept Cardiovasc & Thorac Surg, Med Ctr, Ansan, Gyeonggi Do, South Korea
[2] Univ Nevada, Dept Hlth Care Adm & Policy, Sch Community Hlth Sci, Las Vegas, NV 89154 USA
[3] Soonchunhyang Univ, Dept Hlth Adm & Management, Asan, Chungcheongnam, South Korea
[4] Univ Nevada, Las Vegas Sch Med, Dept Internal Med, Las Vegas, NV 89154 USA
[5] Southern Nevada Vet Affairs Hlth Syst, Dept Med, North Las Vegas, NV USA