Randomized clinical trial examining financial incentives for smoking cessation among mothers of young children and possible impacts on child secondhand smoke exposure

This randomized clinical trial examined whether financial-incentives increase smoking cessation among mothers of young children and potential impacts on child secondhand-smoke exposure (SHSe). 198 women-child dyads were enrolled and assigned to one of three treatment conditions: best practices (BP, N = 68), best practices plus financial incentives (BP + FI, N = 63), or best practices, financial incentives, and nicotine replacement therapy (BP + FI + NRT, N = 67). The trial was completed in Vermont, USA between June 2015 and October 2020. BP entailed staff referral to the state tobacco quitline; financial incentives entailed mothers earning vouchers exchangeable for retail items for 12 weeks contingent on biochemically-verified smoking abstinence; NRT involved mothers receiving 10 weeks of free transdermal nicotine and nicotine lozenges/gum. Baseline, 6-, 12-, 24-, and 48-week assessments were conducted. Primary outcomes were maternal 7-day point-prevalence abstinence and child SHSe through the 24-week assessment with the 48-week assessment exploratory. Results were analyzed using mixed model repeated measures for categorical data. Odds of maternal abstinence were greater among mothers in BP + FI and BP + FI + NRT compared to BP at the 6- and 12-week assessments (ORs >= 7.30; 95% CIs: 2.35-22.71); only abstinence in BP + FI remained greater than BP at the 24-week assessment (OR = 2.95; 95% CIs: 1.06-8.25). Abstinence did not differ significantly between treatment conditions at the 48-week assesssment. There was a significant effect of treatment condition (F[2109] = 3.64, P = .029) on SHSe with levels in BP and BP + FI significantly below BP + FI + NRT (ts[109] >= -2.30, Ps <= 0.023). Financial incentives for smoking abstinence are efficacious for increasing maternal cessation but that alone was insufficient for reducing child SHSe.