1. Division of Clinical Epidemiology, Research Center for Medical Sciences, The Jikei University School of Medicine, Nishishimbashi, Minato-ku, Tokyo, Japan
2. Department of Family and Community Medicine, Hamamatsu University School of Medicine, Handayama, Higashi-ku, Hamamatsu, Japan
3. Department of Primary and Community Care, Radboud University, Geert Grooteplein, EZ Nijmegen, The Netherlands
4. The Community Medical Support Center of the Kumamoto University Hospital, Honjo, Kumamoto Chuo-ku, Kumamoto, Japan
5. The Hokkaido Centre for Family Medicine, Higashi, Higashikukita, Sapporo-shi, Hokkaido, Japan
6. Taito Hospital, Senzoku, Taito-ku, Tokyo, Japan