Study design.
From these 77 students, pre- or post-teaching session questionnaires were unavailable from 6 students: the pre-teaching session questionnaire was missing from one student; during the one-month follow-up survey, two students were absent from the classrooms (one was absent for an unknown reason; another moved out of the area and was no longer a student at the school) and three students did not complete the questionnaire (reasons unknown). Overall, complete data for analysis was available from 36 students in the intervention group and 35 students in the control group.The characteristics of the participating students who were enrolled and randomized are shown in 