Psychometric evaluation of the smoking cessation Processes of Change scale in an adolescent sample.

The Processes of Change are the cognitions, behaviors, and emotions that people employ to change their behaviors. However, the processes of change remain the least studied dimension of the transtheoretical model. The present study presents a psychometric evaluation of the short form of the processes of change inventory for smoking cessation in an adolescent sample of 798 ninth-grade smokers from 22 Rhode Island high schools. The majority of the sample was white (87.2%), split approximately evenly as regards to gender (48.1% female), with an average age of 14.3 (SD=0.6) years of age. The same hierarchical model established on the adult sample was fit to the 20-item inventory. This model included 10 primary factors representing the processes of change and two second order factors that grouped the processes into five behavioral and five experiential processes of change. Model fit indices (RMSEA=0.08, CFI=0.92) supported the hypothesized structure. External validation was established by testing for stage differences in the use of the ten processes. A significant MANOVA (F(4,793)=18.517, p<0.001) and separate ANOVAs demonstrated that the use of all ten processes increased across the stages, as predicted by the transtheoretical model of behavior change. The processes of change help guide researchers, clinicians, and intervention program developers towards effective strategies to assist individuals at all stages of change progress towards healthier behaviors.