STAGE THEORIES OF HEALTH BEHAVIOR - CONCEPTUAL AND METHODOLOGICAL ISSUES

Despite growing interest in stage theories of health behavior, there i s considerable confusion in the literature concerning the essential ch aracteristics of stage theories and the manner in which such theories should be tested. In this article, the 4 key characteristics of a stag e theory-a category system, an ordering of categories, similar barrier s to change within categories, and different barriers to change betwee n categories-are discussed in detail. Examples of stage models of heal th behavior also are described. Four major types of research designs t hat might be used for testing stage theories are examined, including e xamples from the empirical literature. The most commonly used design, which involves cross-sectional comparisons of people believed to be in different stages, is shown to have only limited value for testing whe ther behavior change follows a stage process.