Received: 18 June 2019
Accepted: 27 April 2020
First Online: 1 June 2020
Ethics approval and consent to participate
: The study was reviewed and approved by the ethics committees at King Abdullah International Medical Research Center and the MOE. Permission was obtained from schools, and consents and assents from parents and students were obtained, respectively.
: Not applicable.
: The authors declare that they have no competing interests.