1. Division of General Medicine, Aichi Medical University, Nagakute 480-1195, Aichi, Japan
2. Department of Clinical Infectious Diseases, Aichi Medical University, Nagakute 480-1195, Aichi, Japan
3. Division of Biostatistics, Clinical Research Center, Aichi Medical University, Nagakute 480-1195, Aichi, Japan
4. Department of Palliative and Supportive Medicine, Graduate School of Medicine, Aichi Medical University, Nagakute 480-1195, Aichi, Japan