Data Analyses and Analytic Plan
SE
The objective of the study was to determine whether exposure to efficacy content on tobacco HWLs is associated with increases in quitting intentions, and whether this relationship is mediated by self-efficacy beliefs or perceptions of risk (Model showing pathways and covariates. Covariates shown with striped fill. Abbreviations: SE = Self-efficacy; ITQ = Intention to quit, CPD = Cigarettes per day.To investigate the effects of the intervention over time, it is crucial to disentangle within-person- from between-person effects, as in our study design, “treatment group” (ie exposure to modified HWL) was a person-level (level 2) variable, while both the potential mediators and the outcome of interest were measured repeatedly within-person over time (observation level [level 1] variables). Therefore, we used 2-1-1 multilevel mediation models (Multilevel Structural Equation model with parameter estimates. Abbreviations: SE = Self-efficacy; ITQ = Intention to quit. * = Daily measures of self-efficacy beliefs, risk-perception, and quitting intentions (level-1 variables) were mean-centered within-subject.