1. Center for Health Industry Information and Statistics, Bureau of Health Industry Policy, Korea Health Industry Development Institute, Cheongju, Korea.
2. Department of Health Infrastructure Development, Bureau of Health Technology R&D Planning and Budget Management, Korea Health Industry Development Institute, Cheongju, Korea.
3. Department of Preventive Medicine, Dankook University College of Medicine, Cheonan, Korea.
4. Department of Pharmaceutical Industry, Bureau of Health Industry Promotion, Korea Health Industry Development Institute, Cheongju, Korea.