After these growth curves were described, we examined the subject level correlations between random growth parameters to determine whether levels (i.e., intercepts) of craving, withdrawal/NA and PA were correlated (e.g., are subjects’ reported levels of withdrawal/NA and craving correlated?) and whether instantaneous rates of change in these variables (i.e., linear slopes) were correlated (e.g., are subjects’ rates of change for withdrawal/NA and craving correlated?) at hourly time points after the last cigarette.
