1. Emergency Department; Shengjing Hospital of China Medical University; Shenyang China
2. Institute of Respiratory Disease; the First Hospital of China Medical University; Shenyang China
3. State Key Laboratory of Respiratory Disease; National Clinical Research Center of Respiratory Disease; Guangzhou Institute of Respiratory Diseases; First Affiliated Hospital of Guangzhou Medical University; Guangzhou China
4. Department of Epidemiology; School of Public Health; China Medical University; Shenyang China