Cluster-Randomised Trial

The study randomises schools as clusters in a parallel cluster-randomised controlled design. Eight public national secondary schools in Klang district are randomised equally between intervention and control arms. The control arm receives an attention-matched online flash game without tobacco or vaping content. The design compares areas exposed to the franchising model with areas without exposure. Workshop-attending firms were comparable across treatment and control communities on measured characteristics. Cluster randomised trials randomise intact social groups rather than individuals. The protocol builds on a cluster randomised controlled trial that began in 2024 and involves nearly 1000 daycare firms. Cluster randomised trials can separate the unit of randomisation, the intervention recipient, and the data source. Randomisation assigned 25 communities to treatment and 26 to control after listing and baseline activities. The trial is single-blind because researchers know allocation while participants are kept unaware of group status. The study combines an observational component with a cluster randomised controlled trial to estimate associations and causal impacts. Real cluster r…