The models outlined here (and on subsequent pages) attempt to explain why people adopt (or do not adopt) particular health-related behaviour. The following models and theories will be introduced:

  • The Health Belief Model
  • The Theory of Reasoned Action
  • The Theory of Planned Behaviour
  • Learning Theories
  • The Relapse-Prevention Model
  •  The Transtheoretical model

The Health Belief Model (Becker, 1974)

According to this model, the chances a person will adopt a healthy behaviour depends on the outcome of two assessments they make:

  • The threat of a health problem
  • The pros and cons of taking action.

Looking at the first of these assessments, several factors influence people’s perceived threat of illness or injury, including:

  • Whether they believe they are susceptible to any associated diseases/illness. People evaluate their chances of developing problems; the more vulnerable they perceive themselves to be, the more likely they are to take preventative action.
  • Their perception of the severity of the associated health problems. People consider how severe the consequences are of developing any problems with their health. The more serious they believe these to be, the more likely they are to take preventative action.
  • Cues to action. People who are reminded or alerted about a potential health problem are more likely to take preventative action than those who are not.
  • Demographic variables such as age, sex, race, and ethnicity.
  • Sociopsychological variables such as personality traits, social pressure and social class.
  • Structural variables such as knowledge about or prior contact with the health problem.

For example, an elderly person whose spouse and close friend have developed coronary heart disease largely due to leading a sedentary lifestyle, are more likely to perceive a personal threat of a health problem than a teenager whose friends are in good health.

Taken together, these factors determine the perceived threat of developing a health problem. In weighing the pros and cons of taking preventative action, a person will arrive at a decision on whether the perceived benefits of the action exceeds its perceived barriers/costs.

Other important concepts include general health motivation – a person’s readiness to be concerned about health matters; and perceived control – whether they believe they can do anything about it.

The perceived threat of illness combines with the assessed sum of benefits and barriers to determine the likelihood of preventative action. For example, if a person feels threatened by ill health due to their sedentary behaviour and believe the benefits of physical activity outweigh the barriers, they are likely to go ahead with it. On the other hand, if another person does not feel threatened, or assesses the barriers are too strong, they are unlikely to adopt physical activity into their lifestyle.

Although research has shown this to be an effective model, there are some reported shortcomings however:
“Many important aspects of patients’ decisions fall between the cracks. For example, the model does not provide an adequate explanation for the widespread tendency of patients who have painful heart attacks to delay medical aid … Typically, when the afflicted person thinks of the possibility that it might be a heart attack, he or she assumes that ‘it couldn’t be happening to me’. The patients’ delay of treatment is not attributable to unavailability of medical aid or transportation delays; approximately 75% of the delay time elapses before a patient decides to contact a physician … The important point is that the health belief model, like other models of rational choice, fails to specify under what conditions they will make a more rational decision.” (Janis, 1984)

The model does not take into account how emotions such as anxiety or fear affect rational thought and decision-making.

Click to enlarge.