[1] Kyoto Univ, Grad Sch Med, Dept Thorac Surg, Sakyo Ku, Kyoto 6068507, Japan
[2] Kyoto Univ, Inst Frontier Med Sci, Kyoto 6068507, Japan
[3] Natl Hosp Org Himeji Med Ctr, Dept Thorac Surg, Himeji, Hyogo, Japan
[4] Kyoto Univ, Sch Publ Hlth, Dept Healthcare Econ & Qual Management, Kyoto 6068507, Japan