Affiliation: | 1. Department of Pain and Palliative Medicine, The University of Tokyo Hospital, Tokyo, Japan;2. Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan;3. Department of Anesthesiology and Pain Relief Center, The University of Tokyo Hospital, Tokyo, Japan;4. Department of Health Policy and Informatics, Tokyo Medical and Dental University, Tokyo, Japan |