Discussion
This analysis of the stages of change model as applied to these volunteer intervention subjects provides the most comprehen- sive set of data to test the stage conceptualization of smoking cessation. The results overwhelmingly support the stage catego- ries, Stage X Processes of Change interactions, Stage X Self-Ef- ficacy and Decisional Balance differences, and stage-specific predictions of 1- and 6-month cessation activity. All subjects were smoking as they volunteered for the study and were classi- fied into stages according to intention to quit and previous ces- sation activity. Stage classifications (PC, C, PA) provided robust subgroups of smokers who clearly were at different points in the process of changing their smoking behavior. The magnitude and consistency of the results of this study are quite impressive. There was not one instance in which the or- dering of the effects was contrary to prediction and previous