The item-response probabilities (ρ) for each category of each outcome indicator and the expected class proportions (δ) for the three latent classes at each time point for both outpatient and aftercare participants are provided in Figures 1a and 1b, respectively. These figures show how drinking outcomes defined the three classes, where the y axis represents the probability of responding positively to each item at each time point conditional on latent class membership. For example, at all time points those expected to be nondrinkers had a probability = 1 of endorsing nondrinking for PDD and DDD. Looking at the class proportions, provided in the legend, the majority of participants (57.8% of the outpatients and 75.5% of the aftercare sample) were expected to be nondrinkers immediately after treatment, but there was a decrease in the number expected to be non-drinkers at 6 months (36.7% outpatients and 52.7% aftercare). For outpatients, there was a slight increase in those expected to be nondrinkers at 12 months (40.4%).
