1. Joint Doctoral Program in Global Health, San Diego State University/University of California, San Diego, California, USA
2. Beijing Institute of Respiratory Medicine, Beijing Chao-Yang Hospital, Capital Medical University, WHO Collaborating Center for Tobacco or Health, Beijing, China
3. Beijing Chest Hospital, Capital Medical University, Beijing, China
4. Peking Union Medical College, Beijing, China
5. Graduate School of Public Health, San Diego State University, San Diego, California, USA