Funding for this research was provided by:
National Key Research and Development Plan (2017YFC0112502)
the pediatric medical coordinated development center of Beijing hospitals authority (XTYB201807)
Capital Health Research and Development of Special Funding (2018-1-2091)
Text and Data Mining valid from 2020-03-04
Received: 8 September 2019
Accepted: 5 February 2020
First Online: 4 March 2020
Ethics approval and consent to participate
: Written informed consent and assent were obtained from parents and children (for children ≥12 years of age). The study was approved by the Ethics Committee from Beijing Children’s Hospital.
: Not applicable.
: The authors declare that they have no competing interests.