1. Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine
2. Department of Biostatistics, Hyogo College of Medicine
3. Department of Cardiovascular Surgery, Japan Organization of Occupational Health and Safety Osaka Rosai Hospital
4. Department of Cardiovascular Surgery, Sakurabashi Watanabe Hospital
5. Department of Cardiovascular Surgery, Sakakibara Heart Institute of Okayama
6. Department of Cardiovascular Surgery, Osaka Police Hospital
7. Department of Cardiovascular Surgery, National Hospital Organization Osaka National Hospital