1. The First Clinical Medical School of Lanzhou University; Lanzhou Gansu China
2. Evidence Based Medicine Center of Lanzhou University; Lanzhou Gansu China
3. Nursing Department; Gansu Provincial Hospital; Lanzhou Gansu China
4. Key Laboratory of Evidence Based Medicine and Knowledge Translation of; Gansu Province; Lanzhou Gansu China
5. Department of Obstetric; Gansu Provincial Hospital; Lanzhou Gansu China
6. The Second Department of Gynecology; Gansu Provincial Hospital; Lanzhou Gansu China
7. Department of Medical Psychology; School of Basic Medical Sciences, Lanzhou University; Lanzhou Gansu China