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Behavioral Research

Table of Contents
1 General Description and Theoretical Background
2 Role of Perceived Severity in Health Behaviour Theories
3 Protection Motivation Theory and Extended Parallel Process Model.
4 Measurement Issues

Similar Constructs

6 References
7 Appendices: Severity Measures
8 Published Examples

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Other Constructs



Dispositional Optimism




Illness Representations

  Implementation Intentions
  Intention, Expectation, and Willingness
  Normative Beliefs
  Optimistic Bias
  Perceived Benefits
  Perceived Control
  Perceived Severity
  Perceived Vulnerability
  Self-Reported Behavior
  Social Influence
  Social Support

Perceived Severity
Anne Miles

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Similar Constructs

Fear and worry about illness. These emotions are closely linked to the concept of severity and have been included in some measures of severity, but usually only in the context of the Health Belief Model (e.g. Champion, 1984; Maiman et al., 1977). Other theories and models see emotional response to health threats and disease severity as separate constructs.

Vulnerability. A number of theories promote the view that disease threat is a combination of vulnerability and severity. Threat reduction can occur because the likelihood of a threatening event occurring, or its perceived negative consequences, decrease. However, as noted earlier, there is little consensus about how to combine these two constructs to produce a measure of threat.

Perceived response efficacy. This is the belief that a particular action can reduce a health threat, either by reducing the likelihood of experiencing the threat, reducing its severity, or both. Response efficacy could therefore be measured as the difference in threat perception associated with performing a particular behaviour vs. not performing it. In practice, though, it would be difficult to measure response efficacy this way because of the difficulty in knowing how vulnerability and severity measures should be combined. Perceived response efficacy would therefore usually be measured directly, rather than via the indirect route of reduced threat.

Fatalism. This concept refers to the belief that there is nothing the individual can do to control an outcome. In the context of disease this could relate to beliefs about controlling the likelihood of an outcome occurring in the first place and beliefs about control over its severity. For example, the Powe Fatalism Inventory (PFI; Powe, 1995) assesses beliefs that the individual cannot prevent colorectal cancer from occurring (vulnerability) or cure it once it develops (severity - in this case whether the disease is likely to be fatal or not) .

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Health Behavior Constructs: Theory, Measurement, & Research