1. Department of Pediatrics, Seoul National University College of Medicine, Seoul, South Korea.
2. Department of Biostatistics, College of Medicine, Korea University, Seoul, South Korea.
3. BK21FOUR Program in Learning Health Systems, Korea University, Seoul, South Korea.
4. Department of Internal Medicine, College of Medicine, Korea University, Seoul, South Korea.
5. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.