[1] Natl Canc Control Inst, Natl Hosp Ctr, Natl Canc Ctr, Goyang, South Korea
[2] Natl Canc Control Inst, Natl Canc Ctr, Div Canc Control & Policy, Goyang, South Korea
[3] Natl Hlth Insurance Serv Ilsan Hosp, Dept Internal Med, Div Pulmonol, Goyang Si, South Korea
[4] Natl Hlth Insurance Serv Ilsan Hosp, Dept Res & Anal, Goyang Si, South Korea
[5] Natl Hlth Insurance Serv Ilsan Hosp, Dept Res & Anal, 100 Ilsan Ro, Goyang 10444, South Korea