Causal relationships of processes of change and decisional balance: stage-specific models for smoking.

This study, a secondary analysis of prospective data of smokers, tested whether the causal relationships between the processes of change and decisional balance of the transtheoretical model of change (TTM) are stage-specific. It was expected that for smokers in the contemplation stage, higher levels of experiential processing cause the cons of smoking to become more important and the pros of smoking to become less important. In other words, the level of experiential process use was expected to causally influence decisional balance (pros minus cons) for people in the contemplation stage. For ex-smokers in the action stage, when the cons outweigh the pros (cons become more important while pros become less important), they should increase their behavioral process use: decisional balance was expected to causally influence use of behavioral processes. Cross-lagged panels were analyzed using structural equation modeling. Results indicate that experiential process use has causal predominance over decisional balance for smokers in the contemplation stage. For those in the action stage, however, neither decisional balance nor behavioral process had apparent causal predominance. Mean-level invariance indicates that the contemplation and action stages are different. Further analysis investigated smokers who progressed from contemplation to either preparation or action or from preparation to action. For these smokers who had progressed toward action, decisional balance did causally influence use of behavioral processes. This evidence provides support for the use of the TTM as the basis for planning interventions that target specific stage-dependent causal mechanisms.