Figure 2.
Change in substance use over time by primary and secondary substance use subgroups. Graphs depict modeled means from the generalized estimating equation model for the mean number of days per month of cigarette (A) and (B), alcohol (C) and (D), and illicit drug (E) and (F) use for the primary substance and secondary substance subgroups, respectively. Model was adjusted for treatment group, linear and quadratic effects of time, treatment × (linear and quadratic) time interactions, and pregnancy status. Standard error bars are shown. Abbreviations: e-SBIRT, electronically-delivered Screening, Brief Intervention and Referral to Treatment; SBIRT, clinician-delivered Screening, Brief Intervention, and Referral to Treatment; EUC, Enhanced Usual Care.
