ABSTRACT
Aims. This study examines twelve-step attendance trajectories over seven years, factors associated with the trajectories, and relationships between the trajectories and long-term substance use outcomes among adolescents entering outpatient substance use treatment in a private, non-profit integrated managed care health plan. Design. Longitudinal observational study. Setting. Four Kaiser Permanente Northern California substance use treatment programs. Participants. 391 adolescents entering treatment between 2000 and 2002 who completed at least one follow-up interview in year one, and at least one during years three to seven, after treatment entry. Measurements. Alcohol and drug use, twelve-step meeting attendance and activity involvement, and post-treatment medical service utilization. Findings. Semiparametric group-based modeling identified three distinct twelve-step attendance trajectory groups over seven years: low/no attendance (60%), early but not continued (26%), and continued (14%). There were lower proportions of males and of adolescents with prior substance use treatment experience in the low/no attendance group (p = 0.019 and p = 0.003, respectively). In addition, those in the low/no attendance group had lower perception on circumstances, motivation and readiness for treatment at baseline (p = 0.023). Multivariate logistic generalized estimating equation analyses found that those in the continued group were more likely to be abstinent from both alcohol and drugs during follow-ups than those in the low/no attendance group (OR = 2.40, p = 0.003 and OR = 1.96, p = 0.026, respectively). However, no differences in long-term outcomes were found between those in the other two groups. Conclusion. Robust connection with twelve-step groups appears to be associated with better long-term outcomes among adolescents with substance use disorders.