The relevance of Icek Ajzen's theory of planned behavior for health communication is perhaps best understood relative to the contention that the more one knows about the factors that explain why people engage or do not engage in a particular health behavior, the better able one is to design an intervention that can change or reinforce that behavior. With respect to these considerations, the theory of planned behavior has been quite successful in explaining a broad range of health behaviors. Similarly, there is strong evidence for the effectiveness of behavior change interventions that are guided by the theory.

The theory of planned behavior has its conceptual roots in the reasoned action approach to predicting and changing behavior, which was developed by Martin Fishbein and Icek Ajzen. ...