Latent transition analysis to the stages of change for smoking cessation.

A key construct of the Transtheoretical Model of Behavior Change is the stage of change (Precontemplation, Contemplation, Preparation, Action, and Maintenance) (Prochaska & DiClemente, 1983, 1986). This study applies Latent Transition Analysis (LTA; Collins & Wugalter, 1992; Collins, Wugalter, & Rousculp, 1991) to movement through the stages of change for smoking cessation. LTA is an alternative method of assessing categorical outcome that is sensitive to change, diagnostic, and allows for the comparison of alternative models of change. The sample consisted of 545 reactively recruited smokers and former smokers who were assessed five times over a two year period. LTA was used to compare three specified models. The model that fit the data best indicates that in a six month time frame both progression and regression among the stages takes place as well as two stage progression. Examination of the probability of movement among the stages revealed three findings consistent with the Transtheoretical Model. First, movement through the stages is not always linear. Second, the probability of forward movement was greater than backward movement. Third, the probability of moving to adjacent stages was greater than the probability of two stage progression.