1. Department of Epidemiology, Graduate School of Medicine, Dentistry and Pharmaceutical SciencesOkayama University Okayama Japan
2. Center for Innovative Clinical MedicineOkayama University Hospital Okayama Japan
3. Department of Epidemiology and Preventive Medicine, Graduate School of MedicineGifu University Gifu Japan
4. Department of Human Ecology, Graduate School of Environmental and Life ScienceOkayama University Okayama Japan
5. Department of Health Economics and PolicyGraduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Okayama Japan