Behavior Change Theory With the COM-B Model and the TDF

This part argues for theory and evidence-based behavior change instead of interventions that only seem like a good idea at the time. It defines a behavior, overt or covert, and a behavior change intervention, and places patients on a continuum from passive to active. The COM-B model sits at the center of the behavior change wheel, a synthesis of 19 frameworks. A target behavior needs physical and psychological capability, physical and social opportunity, and reflective and automatic motivation; if one is missing, the behavior will not occur. Intervention functions such as education, persuasion, incentivisation, training, environmental restructuring, modeling and enablement address the deficit, with coercion used rarely if at all. Policy categories are explained as upstream tools, with COVID campaigns as the example. The Theoretical Domains Framework gives more detail on psychological capability and reflective motivation. The part ends on clinical reasoning for behavior change: education only helps when there is a knowledge deficit, and a patient with obesity often already knows the risks but not how to lose weight.