Nurses have a role in helping patients to adopt healthy behaviours. The Theory of Planned Behaviour may help to identify factors affecting their intentions to do this
Models of behaviour change can help identify factors that influence health behaviours such as eating a healthy diet and physical activity. The Theory of Planned Behaviour has been shown to be relatively effective at predicting people’s intention to engage in health-related behaviours. More recent research has explored whether it can help predict the intentions of one group of people to support another group to engage in healthy behaviour. This has implications for nurses, who are often facilitators of patient health. This article gives an overview of the model and discusses its potential implications for nurses.
Citation: McKenzie K (2014) Nurses’ intentions to give lifestyle support. Nursing Times; 110: 26, 20-22.
Author: Karen McKenzie is a chartered clinical psychologist, community child health, at the Royal Hospital for Sick Children, Edinburgh.
- This article has been double-blind peer reviewed
- Scroll down to read the article or download a print-friendly PDF including any tables and figures
It is well established that a poor diet and a lack of exercise can damage health. Along with excessive alcohol consumption and smoking, these are common risk factors for a range of long-term conditions such as cancer, cardiovascular disease and obesity (Scarborough et al, 2011).
In addition to their negative effects on health and life expectancy, poor diet and physical inactivity also harm psychological wellbeing (Associate Parliamentary Food and Health Forum, 2008). They also have an economic impact - the cost of inactivity has been estimated at £0.9bn and of being overweight and obese at £1.5bn in 2006-07 in the UK (Scarborough et al, 2011).
Despite a number of government policies (for example, Scottish Government, 2007; Department of Health, 2004) and interventions that have indicated positive results (for example, Sacher et al, 2010), progress has been slow. While self-reports of physical activity have shown a gradual increase over recent years, objective measures suggest changes may be much lower than reported (Health and Social Care Information Centre, 2009). Likewise, improvements in diet have been limited, with fat and sugar consumption remaining above recommended levels (Bates et al, 2011). This suggests there is a continuing need for changes in health-related behaviours.
Promoting behavioural change
The Theory of Planned Behaviour (Ajzen, 1985) is a motivational model of behavioural change that has been used to predict a range of health behaviours and, more recently, the intentions of one group of people to support another group to engage in healthy behaviours. Since nurses often support others to engage in healthy behaviours, the TPB is likely to be relevant to their practice; information on the model is available.
The TPB argues that behaviour (such as exercise or healthy eating) can be predicted by a person’s intention to engage in the behaviour, which in turn can be predicted by three factors:
- The person’s attitude toward the behaviour;
- How they think others view it (subjective norm);
- The extent to which they have control over it (perceived behavioural control) - this is thought to influence behaviour directly as well as indirectly through the individual’s intentions (Fig 1).
Taking exercise as an example, the likelihood of a woman going to an exercise class would be predicted by her intention to go, which, in turn, would be predicted by the three factors above.
The woman’s attitude towards exercise is what she thinks the outcome will be and how much she values the outcome compared with her perception of the “cost”; if she thinks the overall outcome will be good, she will hold a positive attitude towards exercise. This may be captured by thoughts such as: “It’s a bit of a hassle to go to the class as I’ll get hot and sweaty, but I know I’ll feel great afterwards, so overall it’s worth it.” However, if she feels the overall outcome will be poor, she will hold a negative attitude towards exercise and be less likely to intend to go to the class.
The subjective norm reflects what the woman thinks others who are important in her life think about exercise. If she believes they mainly hold positive views about exercise, she will be more likely to intend to go to the class, whereas if she perceives their views to be negative this will reduce her intention to go.
The above two factors apply to behaviours under a person’s control, so a strong intention to engage in exercise means they are more likely to do so. In reality, external barriers may prevent the intended behaviour from taking place. In this example, the woman and her friends may have positive attitudes towards exercise but she may be unable to attend the class, despite her intentions, because she has to work late.
Perceived behavioural control takes account of the fact that there can be obstacles to behaviour and reflects the person’s perception of these, which might be shaped by beliefs about internal factors, such as level of skill, knowledge or ability, or experience of external barriers, such as a lack of money or transport. As well as influencing intention to take part in a behaviour, perceived behavioural control is thought to influence behaviour directly.
The three TPB factors also interact and influence each other.
Until relatively recently, little was known about how well the TPB could predict behaviour in people supporting others to engage in healthy behaviour. Such research has direct relevance for nurses who are trying to support patients to engage in a healthy lifestyle.
Relevance of the TPB to nurses
Certain patient groups may need additional support in relation to having a healthy lifestyle, such as those with learning disabilities and young people.
People with learning disabilities have a higher prevalence of obesity (Jenkins and McKenzie, 2011) and tend to be less physically active (Martin et al, 2011) than the general population. They often rely on others for help to undertake physical activity (Melville et al, 2008) and to make healthy lifestyle choices (Lunsky et al, 2006). Involving carers has been found to be beneficial when targeting weight problems of people with learning disabilities (Hamilton et al, 2007); however, there are indications that carers can represent a significant obstacle to a healthy lifestyle for those they support when they are resistant to change.
Young people struggling with weight problems may rely on others, such as parents, to help them engage in a healthy lifestyle (Gellar et al, 2012).
Although nurses in a range of settings from schools, primary care and community services to acute hospitals are well placed to identify and support those who are obese or at risk of obesity (Gellar et al, 2012), literature on the effectiveness of nurse-led interventions is limited (Stines et al, 2011). While multiple factors can influence obesity, the key goal is to support a person to increase their physical activity and reduce calorific intake - to promote changes in behaviour.
Nurses can use the TPB as a framework to consider both their own intentions to support a healthy lifestyle in others and to influence the factors believed to predict behaviour change.
Recent research has explored how well the TPB can predict the intentions of one group of people in relation to the diet and physical activity of the other.
Two studies focusing on children and their parents found the TPB predicted parental intention towards their children’s diet (Chambers et al, 2007; Astrom and Kiwanuka, 2006). Two other studies explored its usefulness in predicting carers’ intentions to encourage a healthy diet and physical activity in people with learning disabilities.
Jenkins and McKenzie (2011) found the TPB variables of attitude, subjective norm and perceived behavioural control accounted for nearly a third of all of the factors influencing carer intention to promote healthy eating, with subjective norm the most influential. This meant carers’ intentions to help the people they supported to eat a healthy diet were most influenced by what they believed were the attitudes of important others about healthy eating. Martin et al (2011) found that perceived behavioural control was the most influential factor in relation to carer intention to encourage physical activity. This suggests that increasing carers’ sense of control over their ability to help the people they support to increase physical activity may be an effective strategy to improve the health of people with learning disabilities.
This small but growing body of research suggests that carers’ attitudes, subjective norms and perceived behavioural control can influence the diet and physical activity of those they care for, and highlights the powerful influence carers can have on the health of others. As such, this research has a number of implications for nurses.
As a first step, specific research is needed to explore the extent to which the variables in the TPB model are able to predict nurses’ intentions to support patients to engage in a healthy lifestyle.
While much research has been carried out in relation to diet and exercise, the model may be equally useful in predicting other behaviours, such as intention to support patients with rehabilitation tasks after illness or injury or to quit smoking.
The research suggests the most influential factors may vary, depending on the behaviour. This means that while targeting nurses’ attitudes may be the most important factor in relation to one behaviour, it may be more effective to target subjective norms in relation to another.
Research is also needed to uncover which TPB variables are most important to different aspects of nursing care, and with different patient and age groups, so interventions can be targeted accordingly.
At an individual level, knowledge of the TPB may allow nurses to reflect on which factors seem most influential to their own practice. For example, while nurses will be aware it is difficult to influence change in an environment where their goals are not valued, being able to position this awareness in a TPB theoretical framework as a subjective norm variable may help identify solutions, such as seeking peer support from those who with the same nursing values and goals. Similarly, if, on reflection, a nurse becomes aware of personal attitudes towards a behaviour that are at odds with a health goal (for example, viewing smoking as a positive personal strategy to reduce stress, while supporting others to quit), the TPB provides an explanatory framework as to why this may mean the nurse may not wholeheartedly have behavioural intentions to support patients in giving up cigarettes.
The TPB also offers potentially helpful strategies at an organisational level to improve healthcare. The model suggests that, whatever the desired behavioural outcome, the organisation needs to ensure nurses have positive attitudes towards it, and that they perceive people who are important to them in the workplace, such as colleagues, mentors and managers, to value the behaviour. In addition, organisations need to minimise barriers to supporting the behaviour in others, so nurses perceive themselves to have high levels of control over the desired health behaviour.
In summary, while healthcare is complex and influenced by a wide range of factors, the TPB offers a helpful framework to explore helping behaviour in nurses and the factors that may influence their intention to support others adopt healthy behaviours.
- The Theory of Planned Behaviour (TPB) can be a useful model for predicting intentions to engage in health-related behaviours
- Recent research suggests it can help predict the intentions of one group to support another group
- Nurses often act as facilitators of health in their patients
- The TPB may offer a useful model for identifying factors that affect nurses’ helping intentions
- More research is needed to help tailor interventions to specific health behaviours and patient groups
Ajzen I (1985) From intentions to actions: a theory of planned behaviour. In: Kulhl J, Beckmann J (eds) Action-control: From Cognition to Behaviour. Heidelberg, Springer.
Astrom AN, Kiwanuka SN (2006) Examining intention to control preschool children’s sugar snacking: a study of carers in Uganda. International Journal of Paediatric Dentistry; 16: 10-18.
Associate Parliamentary Food and Health Forum (2008) The Links Between Diet and Behaviour: the Influence of Nutrition on Mental Health. London.
Bates B et al (eds) (2011) National Diet and Nutrition Survey Headline results from Years 1, 2 and 3 (combined) of the Rolling Programme (2008/2009-2010/11). London: Food Standards Agency.
Chambers SA et al (2007) Predicting Healthy Eating Behaviour. Implications of a Nutrition Driven Food Policy for Land Use and the Rural Environment. Reading: University of Reading.
Department of Health (2004) Choosing Health: Making Health Choices Easier. London: DH.
Gellar L et al (2012) Exploratory research to design a school nurse-delivered Intervention to treat adolescent overweight and obesity. Journal of Nutrition Education and Behavior; 44: 1, 46-54.
Hamilton S et al (2007) A review of weight loss interventions for adults with intellectual disabilities. Obesity Reviews; 8: 339-345.
Health and Social Care Information Centre (2009) Health Survey for England 2008: Physical Activity and Fitness. Leeds: HSCIC.
Jenkins CM, McKenzie K (2011) The application of the Theory of Planned Behaviour to diet in carers of people with an intellectual disability. Journal of Applied Research in Intellectual Disabilities; 24: 237-246.
Lunsky Y et al (2006) The clinical profile and service needs of hospitalized adults with mental retardation and a psychiatric diagnosis. Psychiatric Services; 57: 77-83.
Martin E et al (2011) Care staff intentions to support adults with an intellectual disability to engage in physical activity: an application of the Theory of Planned Behaviour. Research in Developmental Disabilities; 32: 2535-2541.
Melville CA et al (2008) The prevalence and determinants of obesity in adults with intellectual disabilities. Journal of Applied Research in Intellectual Disabilities; 21: 425-437.
Sacher P et al (2010) Randomized controlled trial of the MEND Program: a family-based community intervention for childhood obesity. Obesity; 18 (S1): S62-S68.
Scarborough P et al (2011) The economic burden of ill health due to diet, physical inactivity, smoking, alcohol and obesity in the UK: an update to 2006-07 NHS costs. Journal of Public Health; 33: 4, 527-535.
Scottish Government (2007) Better Health, Better Care: Action Plan. Edinburgh: Stationery Office.
Stines EM et al (2011) Nurse practitioner-coordinated childhood obesity early intervention and prevention program. Bariatric Nursing and Surgical Patient Care; 6: 3, 111-114.