1. Department of Cardiology Shengjing Hospital of China Medical University Shenyang China
2. Department of Clinical Epidemiology Department of Library Shengjing Hospital of China Medical University Shenyang China
3. Department of Obstetrics National Office for Maternal and Child Health Surveillance of ChinaWest China Second University HospitalSichuan University Chengdu China
4. Department of Clinical Epidemiology the Fourth Affiliated Hospital of China Medical University Shenyang China