Step 3
REGRESSION, PMT
We estimated the impact of the intervention on PMT construct scores in the last set of models to explore the reasons why the intervention group was more likely to promote smokers from the preparation stage to the action stage. The dependent variables included seven PMT constructs (severity, vulnerability, intrinsic rewards, extrinsic rewards, self-efficacy, response efficacy, and response cost). The explanatory variable was the group (intervention group=1; control group=0). We chose an exchangeable correlation structure for the matrix structure and linear regression for the model setting.