Randomized Controlled Trial Evaluation of a Tailored Leaflet and SMS Text Message Self-help Intervention for Pregnant Smokers (MiQuit)

Introduction: Study aims were to assess the feasibility and acceptability of a tailored self-help smoking cessation intervention for pregnant smokers (MiQuit). Secondary aims were to assess whether MiQuit affected cognitive determinants of quitting and to provide a range of potential effect sizes of the intervention effect on smoking abstinence. Methods: A randomized controlled trial was undertaken in which pregnant smokers were allocated to either receive MiQuit, a tailored self-help leaflet followed by an 11-week program of tailored text messages, or to a control group, receiving a nontailored self-help leaflet. Participants were 207 pregnant smokers identified by community midwives across 7 NHS Trusts (United Kingdom). At 3-month follow-up, intervention acceptability, cognitive determinants of quitting, and smoking outcomes (self-reported and cotinine-validated 7-day point prevalence abstinence) were assessed. Results: Feasibility: 94% (95% CI 89%–99%) of MiQuit participants reported receiving both intervention components. Acceptability: 9% (95% CI 4%–15%) of MiQuit participants opted to discontinue the text messages. Mechanism: compared with controls, MiQuit participants were more likely to set a quit date (p = .049) and reported higher levels of self-efficacy (p = .024), harm beliefs (p = .052), and determination to quit (p = .019). Potential efficacy: self-reported abstinence—MiQuit 22.9%, control 19.6%; odds ratio (OR) = 1.22, 95% CI 0.62–2.41; cotinine-validated abstinence—MiQuit 12.5%, control 7.8%; OR = 1.68, 95% CI 0.66–4.31. Conclusions: Delivering tailored smoking cessation support to pregnant smokers via leaflet and text message is feasible and acceptable. The positive effects of MiQuit on cognitive determinants and the likelihood of setting a quit date are encouraging. A larger efficacy trial is warranted