Importance of Considering Hospital-Level Variables in Multi-Institutional Studies

Affiliations

• ¹ Department of General Medicine, Oita University Faculty of Medicine, Oita, Japan.
• ² Department of Pharmacoepidemiology, Kyoto University Graduate School of Medicine and Public Health, Kyoto, Japan.
• ³ Department of General Internal Medicine, National Hospital Organization Nagasaki Medical Center, Nagasaki, Japan.
• ⁴ Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan.
• ⁵ Department of Preventive Medicine and Public Health, Keio University School of Medicine, Tokyo, Japan.