Parents' Self-efficacy for Tobacco Exposure Protection and Smoking Abstinence Mediate Treatment Effects on Child Cotinine at 12-Month Follow-up: Mediation Results from the Kids Safe and Smokefree Trial

Introduction: Compared with the general smoking population, low-income smokers face elevated challenges to success in evidence-based smoking cessation treatment. Moreover, their children bear increased disease burden. Understanding behavioral mechanisms related to successful reduction of child tobacco smoke exposure (TSE) could inform future smoking interventions in vulnerable, underserved populations. Methods: Smoking parents were recruited from pediatric clinics in low-income communities and randomized into a multilevel intervention including a pediatric clinic intervention framed in best clinical practice guidelines ("Ask, Advise, Refer"[AAR]) plus individualized telephone counseling (AAR + counseling), or AAR + control. Mediation analysis included treatment condition (independent variable), 12-month child cotinine (TSE biomarker, criterion), and four mediators: 3-month end-of-treatment self-efficacy to protect children from TSE and smoking urge coping skills, and 12-month perceived program (intra-treatment) support and bioverified smoking abstinence. Analyses controlled for baseline nicotine dependence, depressive symptoms, child age, and presence of other residential smokers. Results: Participants (n = 327) included 83% women and 83% African Americans. Multilevel AAR + counseling was associated with significantly higher levels of all four mediators (ps <. 05). Baseline nicotine dependence (p <. 05), 3-month self-efficacy (p <. 05) and 12-month bioverified smoking abstinence (p <. 001) related significantly to 12-month child cotinine outcome. The indirect effects of AAR + counseling intervention on cotinine via self-efficacy for child TSE protection and smoking abstinence (ps <. 05) suggested mediation through these pathways. Conclusions: Compared with AAR + control, multilevel AAR + counseling improved all putative mediators. Findings suggest that fostering TSE protection self-efficacy during intervention and encouraging parental smoking abstinence may be key to promoting long-term child TSE-reduction in populations of smokers with elevated challenges to quitting smoking. Implications: Pediatric harm reduction interventions to protect children of smokers from tobacco smoke have emerged to address tobacco-related health disparities in underserved populations. Low-income smokers experience greater tobacco-related disease burden and more difficulty with smoking behavior change in standard evidence-based interventions than the general population of smokers. Therefore, improving knowledge about putative behavioral mechanisms of smoking behavior change that results in lower child exposure risk could inform future intervention improvements.