1. Department of Public Health, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
2. M3 Inc, Akasaka Intercity, Minato-ku, Tokyo, Japan
3. Division of General Internal Medicine and Health Services Research, David Geffen School of Medicine at UCLA, Los Angeles, California
4. Department of Health Policy and Management, UCLA Fielding School of Public Health, Los Angeles, California