The Kaiser Permanente Prenatal Smoking-cessation Trial: when More Isn't Better, What is Enough?

Introduction: The effectiveness of low-cost smoking interventions targeted to pregnant women has been demonstrated, although few gains in absolute cessation rates have been reported in the past decade. Under conditions of typical clinical practice, this study examined whether outcomes achieved with brief counseling from prenatal care providers and a self-help booklet could be improved by adding more resource-intensive cognitive-behavioral programs.

Design: Randomized Clinical Trial.

Setting: A large-group-model managed care organization.

Participants: 390 English-speaking women 18 years of age or older who self-reported to be active smokers at their initial prenatal appointment.

Intervention: Participants were randomized to one of three groups: (1) a self-help booklet tailored to smoking patterns, stage of change, and lifestyle of pregnant smokers; (2) the booklet plus access to a computerized telephone cessation program based on interactive voice response technology; or (3) the booklet plus proactive telephone counseling from nurse educators using motivational interviewing techniques and strategies. No attempt was made to change smoking-related usual care advice from prenatal providers.

Main Outcome Measure: Biochemically confirmed abstinence measured by level of cotinine in urine samples obtained during a routine prenatal visit at approximately the 34th week of pregnancy.

Results: Twenty percent of participants were confirmed as abstinent with no significant differences found between intervention groups. Multivariate baseline predictors of cessation included number of cigarettes smoked per day, confidence in ability to quit, exposure to passive smoke, and educational level. No differential intervention effects were found within strata of these predictors or by baseline stage of readiness to change. Cessation rates among heavier smokers were strikingly low in all intervention groups.

Conclusion: Neither a computerized telephone cessation program nor systematic provision of motivational counseling improved cessation rates over a tailored self-help booklet delivered within the context of brief advice from prenatal providers. Innovative strategies need to be developed to increase the effectiveness of existing prenatal smoking interventions. Special attention should be paid to the needs of heavier smokers.