Funding for this research was provided by:
National Natural Science Foundation of China (81401678, 81601778)
Research Foundation of the Capital Institute of Pediatrics (FX-2019-05)
the Special Fund of the Pediatric Medical Coordinated Development Center of the Beijing Municipal Administration of Hospitals (XTZD20180505)
Text and Data Mining valid from 2020-01-28
Received: 9 October 2019
Accepted: 28 December 2019
First Online: 28 January 2020
Ethics approval and consent to participate
: The present project was performed in compliance with the Helsinki Declaration (Ethical Principles for Medical Research Involving Human Subjects) and was approved by the research board of the Ethics Committee of Capital Institute of Pediatrics. All patient data were anonymously reported. Based on the guidelines of the Ethics Committee of Capital Institute of Pediatrics, informed consent was not sought from the patients.
: Not applicable.
: The authors declare that they have no competing interests.