To estimate the effectiveness of pregnancy smoking cessation support delivered by SMS text message and key parameters needed to plan a definitive trial.
Multicentre, parallel-group, single-blinded, individual randomised controlled trial SETTING: 16 antenatal clinics in England.
407 participants were randomised to the intervention (n = 203) or usual care (n = 204). Eligible women were <25 weeks gestation, smoked at least 1 daily cigarette (>5 pre-pregnancy), were able to receive and understand English SMS texts and were not already using text-based cessation support.
All participants received a smoking cessation leaflet; intervention participants also received a 12-week programme of individually-tailored, automated, interactive, self-help smoking cessation text messages (MiQuit).
Seven smoking outcomes including validated continuous abstinence from 4 weeks post-randomisation until 36 weeks gestation, design parameters for a future trial and cost-per-quitter.
Using the validated, continuous abstinence outcome, 5.4% (11/203) of MiQuit participants were abstinent versus 2.0% (4/204) of usual care participants (odds ratio [OR] 2.7, 95% confidence interval [CI] 0.93 to 9.35). The Bayes Factor for this outcome was 2.23. Completeness of follow up at 36 weeks gestation was similar in both groups; provision of self-report smoking data was 64% (MiQuit) and 65% (usual care) and abstinence validation rates were 56% (MiQuit) and 61% (usual care). The incremental cost-per-quitter was £133.53 (95% CI -£395.78 to £843.62).
There was some evidence, though not conclusive, that a text messaging programme may increase cessation rates in pregnant smokers when provided alongside routine NHS cessation care.