2.3. Recruitment and Randomization
SECONDARY, RECRUITMENT
Consecutive sampling was used for the recruitment stage. Cluster randomization of the schools was carried out to minimize the contamination anticipated from recruiting subjects from the same school. Notably, the study was conducted in two randomly selected secondary schools in Al Seeb Wilayat in Muscat region. The participants in the intervention group (school A) and those in the control group (school B) were recruited from two separate schools, which were located in different areas and were maintained at an adequate distance from each other within Al Seeb Wilayat.