1. Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Japan
2. Department of Health Services Research, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
3. Health Services Research and Development Center, University of Tsukuba, Tsukuba, Japan
4. Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan
5. Department of Health Policy and Informatics, Tokyo Medical and Dental University Graduate School of Medicine, Tokyo, Japan.