Commitment to health theory.

This article introduces commitment to health as a middle-range. Commitment to health (CTH) is derived from Prochaska and DiClemente's (1983) Transtheoretical Model of Behavior Change. CTH theory is designed to predict the likelihood of behavior change between the action and maintenance stages of change. Commitment is defined as a freely chosen internal resolve to perform health behaviors, even when encumbered or inconvenienced by difficulties. Health is defined as the optimal level of well-being. Commitment is an independent continuous variable, but it can be categorized into three time-oriented categories: (1) low-level, (2) middle-level, and (3) high-level commitment. The higher the level of commitment, the more likely the individual will adopt long-term behavior change. This article presents the definitions, assumptions, and relational statements of CTH.