METHODS
Based on the mortality surveillance data for Guangdong Province, we conducted a study in two rural townships in Qingyuan City, namely, Jintan and Longjing, which feature abundant nature and man-made bodies of water and high mortality rates due to drowning. We used the cluster random sampling strategy to assign the two townships into intervention (Jintan) and control (Longjing) groups through simple randomization (i.e. a coin toss). The study recruited students from 23 schools (18 elementary schools and 5 middle schools) in the two towns. The students were cluster randomized into the intervention or control group. The target populations were all students in Grades 3–8 (8–18 years old) at baseline and Grades 3–9 at the final evaluation (18 months after the intervention).