Stage transitions and the transtheoretical “stages of change” model of smoking cessation 1Joseph P. Carbonari, Ed.D., Kenneth B. Sewell, M.S., M.A. are in the Psychology Department at the University of Houston. Carlo C. DiClemente, Ph.D., is Chair of the Psychology Department at the University of Maryland, Baltimore County. This research was partially supported by Grant CA 27821 from the National Cancer Institute. Portions of these findings were derived from the Master's Thesis of Kenneth B. Sewell and were presented at the 102nd convention of the American Psychological Association in Los Angeles, August 12-16, 1994. There are many staff and volunteers of the Change Assessment Research Program at the University of Houston who have contributed to the collection of data for this study. We gratefully acknowledge all those who participated in this project.

Abstract

This study examined the application of a Markov chain analysis for modeling transitions in the process of smoking cessation from the perspective of the Transtheoretical “Stages of Change” model. A convenience sample of 308 individuals, who were followed at 6-month intervals for a 30-month period, answered questionnaires regarding their past and current smoking behavior, and their quitting attempts and intentions. A first order, single transition, Markov model was found to fit the data well, indicating that stage information from a single previous 6 month time point was sufficient to predict current stage membership. A composite transition probability matrix indicated that significant stability occurred in Precontemplation, Contemplation, and Maintenance stages with greater transitions among stages for smokers in Preparation and Action stages. In addition, more people tended to progress in stage status toward successfully maintained cessation than to either regress or make no change in stage membership over the 2 1/2 years of the study. These results support the utility of stage based models of change in understanding the process of smoking cessation. Smoking cessation is marked by significant periods of stasis as well as recycling through the stages. For a significant number of this cohort of participants there was progress and movement toward successful change that seemed to support the spiral movement through the stages of change proposed by the Transtheoretical “stages of change” model.