Eliminating children’s tobacco smoke exposure: a pathway to bioverified abstinence among low-income maternal smokers in the Babies Living Safe and Smokefree (BLiSS) trial

Background: Identifying behavioral pathways to smoking cessation in high-risk populations, such as low-income maternal smokers, could reduce tobacco disparities. The previous “BLiSS” multilevel intervention trial demonstrated efficacy of the BLiSS intervention in facilitating low-income maternal smokers’ bioverified abstinence. This present study examined four putative pathways measured at 3-month end of treatment (Time 2) that could account for the observed intervention effect on smoking abstinence through 12 months (Time 2 – Time 3). Methods: Nutritionists in community clinics delivering safety net nutrition promotion programs across Philadelphia, Pennsylvania, USA, were trained by trial principal investigators to deliver a brief tobacco intervention informed by the American Academy of Pediatrics best practice guidelines (“Ask, Advise, Refer [AAR]”). After referral, 396 eligible participants were randomized to either a multimodal behavioral intervention (AAR + MBI) or a parallel attention control (AAR + control). Random effects regression analysis tested mediation. Results: Elimination of children’s tobacco smoke exposure (TSE) at Time 2 was the only significant mediator of longitudinal smoking abstinence through Time 3. AAR + MBI mothers were more likely to eliminate their children’s TSE by Time 2 (OR = 2.11, 95%CI 1.30, 3.42), which was significantly associated with Time 3 abstinence (OR = 6.72, CI 2.28, 19.80). Modeling showed a significant total effect of AAR + MBI on abstinence (OR = 6.21, CI 1.86, 20.71), a direct effect of AAR + MBI on abstinence (OR = 4.80, CI 1.45, 15.94) and an indirect effect through TSE elimination (OR = 1.29, CI 1.06, 1.57). Conclusions: Integrating smoking cessation interventions with counseling prior to the quit attempt that is designed to facilitate adoption of smokefree home policies and efforts to eliminate children’s TSE could enhance the likelihood of long-term abstinence in populations of smokers with elevated challenges quitting smoking.