Study design
Based on the hospital outpatient service system, we reviewed all
electronic medical record (EMR) of outpatients treated in the Pediatric
and Adolescent Gynecology (PAG) Department in the Children’s Hospital,
Zhejiang University School of Medicine from January 2006 to December
2018. The study was approved by the Human Subjects Committees of the
Children’s Hospital, Zhejiang University School of Medicine.