The document discusses several models of health behavior:
1) The Basic Risk Perception Model focuses on likelihood and severity of harm from not acting. Higher risk perception predicts greater motivation to act.
2) The Health Belief Model includes perceived susceptibility, severity, benefits, and barriers in predicting preventive health behaviors. Perceived barriers are the strongest predictor.
3) Protection Motivation Theory assesses threat and coping appraisal processes. Response costs have the strongest impact on health behaviors and attitudes.
4) The Transtheoretical Model proposes stages of change and processes of change to explain behavior progression. Decisional balance and self-efficacy also predict stage of change.