Participant- and study-related characteristics predicting treatment completion and study retention in an adolescent smoking cessation trial

Purpose: To determine which factors predict smoking cessation treatment completion and retention among adolescents.

Methods: In a multisite, randomized, controlled trial, the efficacy of motivational interviewing was compared with structured brief advice for smoking cessation and reduction in adolescents (n = 355) aged 14-18 years (55% female, 45% black, 12% Hispanic). Treatment spanned 12 weeks, with follow-up assessments at 24 weeks. Treatment completion was defined as completion of all five counseling sessions. Study retention was defined as completing the 24-week assessment. Participant and study variables served as predictors of treatment completion and retention.

Results: In all, 79% of participants completed all five counseling sessions and the same percent completed the 24-week assessment. Black race, precontemplation stage to cut back, and shorter length of time between the baseline assessment and the first counseling session were significantly associated with treatment completion. For every 7.5-day delay in starting treatment after the baseline visit, there was a 50% decrease in the odds of completing all five treatment sessions. Retention at 24 weeks was predicted by black race, younger age, greater maternal education, expectations of graduating college, and structured brief advice intervention.

Conclusions: High rates of treatment completion and study retention can be achieved in a multisession, behavioral intervention for adolescent smoking cessation. Findings suggest that treatment should begin soon after the intake session to maximize treatment completion. Enhanced efforts to retain older adolescents and youth with lower academic goals and lower family income will be important in future studies.