Figure 1.

Path analytic model of proposed study relationships. Age, sex, and ethnicity (all T1) were entered into the model as covariates but are not pictured to maintain conceptual clarity. T1 substance use also was controlled for. T1 substance use variables (e-cig, CTC, and marijuana) also were entered in the model. Paths between marijuana use (T1) with family e-cigarette use (T1), positive expectancies (T1), and adolescent cigarette use at (T2), and paths between e-cigarette use (T1) and cigarette use (T2) were included in the estimated model, but were not statistically significant, and are not pictured. Covariance between positive expectancies and willingness was estimated but is not pictured to provide diagrammatic simplicity. T = time. *p < .05, **p < .01, ***p < .001.