A randomized controlled trial of smoking cessation for pregnant women to test the effect of a transtheoretical model-based intervention on movement in stage and interaction with baseline stage.

OBJECTIVES: To examine whether, as predicted by the transtheoretical model (TTM), stage-matched interventions will be more effective than stage-mismatched interventions. DESIGN: Randomized controlled trial of smoking cessation advice to pregnant smokers. METHODS: Pregnant women currently smoking at 12 weeks gestation were enrolled in a pragmatic three-arm trial of TTM-based interventions to help them stop smoking. One arm constituted standard midwifery advice and a self-help leaflet on stopping smoking, which is generally appropriate for women in preparation. Two arms were TTM-based. Differences in positive movement in stage towards quitting from enrolment to 30 weeks gestation and 10 days post-partum were calculated for each arm of the trial. We then examined whether, as predicted from the TTM, the relative benefit of the TTM-based intervention was greater for women in precontemplation and contemplation, for whom the control intervention was stage-mismatched, than for women in preparation, for whom the control intervention was stage-matched. RESULTS: Women in the TTM-based arms were statistically significantly more likely to move forward in stage than were women in the control arm. Contrary to the TTM-derived hypothesis, the greater relative benefit of the TTM-based intervention was seen for women in preparation stage at baseline, rather than women in precontemplation and contemplation. CONCLUSIONS: The TTM-based intervention was more effective in stage movement, but this could be due to its greater intensity. The failure to confirm that stage-matching was important casts doubt on the validity of the TTM in explaining smoking cessation behaviour in pregnancy.

The influence of in-pregnancy smoking cessation programmes on partner quitting and women's social support mobilization: a randomized controlled trial [ISRCTN89131885].

BACKGROUND: Smoking cessation interventions in pregnancy could influence a woman's social behaviour and her partner's smoking behaviour, but this has not been examined in any published randomized trials. METHOD: 918 women smoking at booking for antenatal care were enrolled in a cluster-randomized trial of three interventions: standard care, self-help manual and enhanced stage-based counselling, or self-help manual, enhanced stage-based counselling and use of an interactive computer program. The outcomes were change in social support received by women between booking for maternity care and 30 weeks gestation and 10 days postpartum and reported cessation in the woman's partner at these times. RESULTS: Few pregnant women's partners stopped smoking (4.1% at 30 weeks of gestation and 5.8% at 10 days postpartum) and the probability of quitting did not differ significantly by trial arm. Women's scores on the Inventory of Socially Supportive Behaviors showed a slight decline from booking to 30 weeks gestation, and a slight increase to 10 days postpartum, but these changes did not differ significantly by trial arm. CONCLUSION: The stage-based interventions tested in this trial aimed partly to influence women's mobilization of support and might have influenced partners' quitting, but there was no evidence that they did so. Given that women and their partners often stopped smoking together, future interventions to prevent smoking in pregnant women could encourage both partners to quit together.

Is advice to stop smoking from a midwife stressful for pregnant women who smoke? Data from a randomized controlled trial.

BACKGROUND: There are no randomized trials examining whether intensive advice to pregnant smokers is more stressful than standard care. METHOD: Nine hundred eighteen U.K. women currently smoking on commencing antenatal care were randomized into three arms. Women in Arm A received one episode of brief advice to stop smoking. Women in Arm B were assessed for stage of change and worked through an exercise in self-help manuals on three occasions. Women in Arm C used a 20-min interactive computer program three times in addition to the intervention women in Arm B received. Stress was assessed by the change in score on the Perceived Stress Scale (PSS) from baseline to 30 weeks gestation, the month before delivery, and 10 days postpartum. RESULTS: There were small and not significant differences in the changes in PSS between the arms at all outcome times. There was no evidence that the importance women attached to pleasing their midwife by stopping, having failed to quit, or nulliparity modified the effect of intensive advice on change in stress levels. CONCLUSIONS.: Intensive advice to stop smoking was not associated with increases in stress. Advice and support for pregnant women to stop smoking should be given without fear of causing stress.

Does stage-based smoking cessation advice in pregnancy result in long-term quitters? 18-month postpartum follow-up of a randomized controlled trial.

AIMS: To evaluate the effect on quitting smoking at 18 months postpartum of smoking cessation interventions based on the Transtheoretical Model (TTM) delivered in pregnancy compared to current standard care. It has been claimed that TTM-based interventions will continue to create quitters after the end of the intervention period. DESIGN: Cluster randomized trial. SETTING: Antenatal clinics in general practices in the West Midlands, UK. PARTICIPANTS: A total of 918 pregnant smokers originally enrolled in the trial, of which 393 women were followed-up at 18 months postpartum. INTERVENTIONS: One hundred general practices were randomized into the three trial arms. Midwives in these practices delivered three interventions: A (standard care), B (TTM-based self-help manuals) and C (TTM-based self-help manuals plus sessions with an interactive computer program giving individualized smoking cessation advice). MEASUREMENTS: Self-reported continuous and point prevalence abstinence since pregnancy. FINDINGS: When combined together, there was a slight and not significant benefit for both TTM arms compared to the control, with an odds ratio (OR) 95% confidence interval (CI) of 1.20 (0.29-4.88) for continuous abstinence. For point prevalence abstinence, the OR (95%CI) was 1.15 (0.66-2.03). Seven of the 54 (13%) women who had quit at the end of pregnancy were still quit 18 months later, and there was no evidence that the TTM-based interventions were superior in preventing relapse. CONCLUSIONS: The TTM-based interventions may have shown some evidence of a short-term benefit for quitting in pregnancy but no benefit relative to standard care when followed-up in the longer-term.

What happens to women's self-reported cigarette consumption and urinary cotinine levels in pregnancy?

AIMS: To describe the pattern of self-reported cigarette consumption and nicotine consumption, measured by urinary cotinine concentration, in a cohort of pregnant women who did not stop smoking. DESIGN: Cohort study. SETTING: Randomly selected general practices from the West Midlands, UK. PARTICIPANTS: Five hundred and fifty-nine pregnant women in a clinical trial who were enrolled at booking for maternity care (about 12 weeks of gestation), who were followed up in mid and late pregnancy and 10 days post-natal and who did not stop smoking during that period. MEASUREMENTS: Retrospectively collected self-reported cigarette consumption prior to pregnancy and contemporaneously collected self-reported cigarette consumption and urinary cotinine concentrations at booking for maternity care, 20 weeks of gestation, 30 weeks of gestation and 10 days post-natal. FINDINGS: Women reported smoking a median of 10-19 cigarettes per day prior to pregnancy and a median of 5-9 cigarettes per day at booking for maternity care. At booking, women reported consuming a mean [95% confidence interval (CI)] of 6.3 (5.6-7.0) cigarettes per day. At 20 weeks of pregnancy this had risen to mean (95% CI) 11.5 (10.9-12.2), and remained at 11 cigarettes per day when measured again at 30 weeks of gestation and 10 days post-natal. Mean (95% CI) urinary cotinine levels at booking were 6.0 (5.4-6.6) microg/mL, and did not change much through pregnancy. There were statistically significant associations between urinary cotinine and reported cigarette consumption at all time points except at booking. CONCLUSIONS: Women smokers report lower cigarette consumption at booking for maternity care than they do prior to pregnancy or from mid pregnancy onwards, but cotinine data imply that their intake of toxins does not change throughout pregnancy. Reports suggesting many women reduce their smoking in pregnancy have probably been over-optimistic.

A controlled trial of an expert system and self-help manual intervention based on the stages of change versus standard self-help materials in smoking cessation.

AIM: To examine the population impact and effectiveness of the Pro-Change smoking cessation course based on the Transtheoretical Model (TTM) compared to standard self-help smoking cessation literature. DESIGN: Randomized controlled trial. SETTING: Sixty-five West Midlands general practices. PARTICIPANTS: Randomly sampled patients recorded as smokers by their general practitioners received an invitation letter and 2471 current smokers agreed. INTERVENTIONS: Responders were randomized to one of four interventions. The control group received standard self-help literature. In the Manual intervention group, participants received the Pro-Change system, a self-help workbook and three questionnaires at 3-monthly intervals, which generated individually tailored feedback. In the Phone intervention group, participants received the Manual intervention plus three telephone calls. In the Nurse intervention group, participants received the Manual intervention plus three visits to the practice nurse. MEASUREMENTS: Biochemically confirmed point prevalence of being quit and 6-month sustained abstinence, 12 months after study commencement. FINDINGS: A total of 9.1% of registered current smokers participated, of whom 83.0% were not ready to quit. Less than half of participants returned questionnaires to generate second and third individualized feedback. Telephone calls reached 75% of those scheduled, but few participants visited the nurse. There were small differences between the three Pro-Change arms. The odds ratio (95% confidence intervals) for all Pro-Change arms combined versus the control arm were 1.50 (0.85-2.67) and 1.53 (0.76-3.10), for point prevalence and 6-month abstinence, respectively. This constitutes 2.1% of the TTM group versus 1.4% of the control group achieving confirmed 6-month sustained abstinence. CONCLUSIONS: There was no statistically significant benefit of the intervention apparent in this trial and the high relapse of quitters means that any population impact is small.