Making the Most of Plain Packaging (MMoPP) - Data Files

Background: Smokers can respond defensively to health risk communication such as on-pack warning labels, potentially reducing their effectiveness. Theory suggests that risk perception together with self-efficacy reduces defensive responses and predicts target behaviours. Currently, tobacco warning labels globally predominantly target risk and do not explicitly consider efficacy. This study explores the effectiveness of combining Australian tobacco warning labels with efficacy content to increase quitting intentions. Methods: RCT in 83 smokers over three weeks. After a seven-day baseline phase (smoking from usual tobacco packaging), participants were randomised to one of two adhesive labels groups for the remaining 14 days: standard health warning labels (HWLs) featuring enhanced efficacy messages (experimental group) or unmodified standard HWLs (control group). Participants attached these labels to their tobacco packaging and recorded their cognitions and smoking behaviour once daily using smartphones. Multi-level structural equation modelling was used to test theorised effects of the labels on self-efficacy, risk perception and intentions to quit.