Funding for this research was provided by:
Birjand University of Medical Sciences (1395.131)
Received: 15 January 2020
Accepted: 19 August 2020
First Online: 16 September 2020
Ethics approval and consent to participate
: The protocol of this research was approved by the Deputy of Birjand University of medical sciences and its ethics committee (ir.bums. REC.1395.131). The written informed consent was obtained from the parents.
: Not Applicable.
: The authors have no competing interests.