The status of evidence and outcomes in Stages of Change research.

The Stages of Change model has become a prominent feature within health promotion and most of the literature associated with the model portrays it as being 'effective'. Based on an extensive review of the literature, this paper suggests that contrary to this view, there exist a relative paucity of sufficiently strong supportive evidence. The paper describes the features of the existing evidence base, and highlights problems in relation to various aspects of design and execution. Two wider issues relating to the core nature of the model and the evidence associated with it are identified as important and discussed. Two main conclusions are drawn. First, better quality quantitative outcome studies are needed. These should be complemented with significant qualitative case studies with a focus on practitioner and organizational utilization of the model. Second, the disproportionate popularity of the model may be skewing the practical and conceptual nature of health promotion. Stages of Change activities are seen to equate to 'health promotion' at the expense of other activities and approaches.