Recruitment and retention
RECRUITMENT
The recruitment of children aged 4–6 years was carried out from January to March 2017 from 48 kindergartens. A total of 22 and 26 kindergartens participated as the intervention and control groups respectively. A total of 1072 children from three ethnics groups (Malay, Iban, and Bidayuh), in Kuala Lumpur and Selangor (Peninsular Malaysia), Bau, Lundu, Samarahan, and Siburan (East Malaysia) were invited. Following that, 1001 children whose parents consented to the study were recruited into the RCT whereby 498 children were randomized to the intervention group and another 503 to the control group. Nevertheless, after the first measurement (T1), only 484 children remained in the intervention group and 463 in the control group. Among the reasons for dropout were absence from the kindergartens despite several attempts to reach them and parental decision to withdraw from the study.At the end of the intervention, a total of 837 children completed the program successfully, giving a retention rate of 88.4% (Table Overall retention rate of the participantsFlow chart of participant recruitment and retention