1. Hospital Infection‐Control Department Xi'an Aerospace General Hospital Xi'an Shaanxi P.R. China
2. School of Public Health, Center for Laboratory and Simulation Training, Center for Evidence‐Based Medicine Gansu University of Chinese Medicine Lanzhou Gansu China
3. School of Nursing Gansu University of Chinese Medicine Lanzhou Gansu China
4. Department of Public Health Affiliated Hospital of Gansu University of Chinese Medicine Lanzhou China
5. School of Public Health, Evidence Based Social Science Research Center Lanzhou University Lanzhou China