1. Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Ehime, Japan
2. Department of Healthcare Quality Assessment, Graduate School of Medicine, The University of Tokyo, Division of Clinical Epidemiology, Translational Medical Center, National Center of Neurology and Psychiatry, Tokyo, Japan
3. Department of Cardiac Surgery, The University of Tokyo, Tokyo, Japan
4. Department of Health Policy and Management, School of Medicine, Keio University, Tokyo, Japan
5. Department of Pediatric Cardiac Surgery, Saitama Medical University International Medical Center, Saitama, Japan