Text messaging interventions may offer promise for health systems, but we need more evidence. We investigated efficacy of three text messaging programs in helping smokers quit. Arm 1 had cessation assessment and quit date reminder messages. Arm 2 had Arm 1 messages plus quit date preparation messages. Arm 3 had Arm 1 and Arm 2 messages plus 6 weeks of post-quit date messaging. Smokers aged 18–29 interested in quitting were randomly assigned to a study arm. We surveyed participants at baseline, and at 3, 8, 20, and 32 weeks (n = 4,027). At 8 weeks, scores on psychological measures were higher in Arm 3 than in Arm 2 or Arm 1. Seven-day smoking abstinence was higher in Arms 3 and 2 than in Arm 1 after controlling for background and psychological measures. Arm 3 affected quitting the most, suggesting motivational text messages before, on, and after an individual’s quit date may increase quitting.
