Do processes of change predict smoking stage movements? A prospective analysis of the transtheoretical model

The transtheoretical model (TTM) posits that processes of change and the pros and cons of smoking predict progressive movement through the stages of change. This study provides both a cross-sectional replication and a prospective test of this hypothesis. As part of a larger study of worksite cancer prevention (the Working Well Trial), employees of 26 manufacturing worksites completed a baseline and 2 annual follow-up surveys. Of the 63% of employees completing baseline surveys, 27.7% were smokers (N = 1,535), and a cohort of these smokers completed the 2-year follow-up. Cross-sectional results replicated previous studies with virtually all the processes of change and the cons of smoking increasing in linear fashion from precontemplation to preparation (all ps < .00001), and the pros of smoking decreasing (p < .01). However, contrary to the hypothesis, the baseline processes of change and the pros and cons of smoking failed to predict progressive stage movements at either the 1- or the 2-year follow-ups. Possible explanations for these findings and concerns about the conceptual internal consistency of the TTM are discussed.