Ethics approval and consent to participate
Ethical approval for this study was obtained from the Universiti Malaysia Sarawak Medical Ethics Committee (UNIMAS/NC-21.02/03–02 Jld.2 68) and the Universiti Kebangsaan Malaysia Research Ethics Committee (UKM PPI/111/8/JEP-2017–658). Permission to conduct the study was also obtained from the Community Development Department, Ministry of Rural and Regional Development, Malaysia. Informed consent was obtained from the parents using a form prepared in the Malay language before the children participated in the study. All methods were performed in accordance with the relevant guidelines and regulations.