02 048549_hobbi_(jr/t) 11/11/04 2:09 pm Page 7 Journal of Health Psychology Are Techniques Used Copyright © 2005 SAGE Publications London, Thousand Oaks and New Delhi, in Cognitive Behaviour www.sagepublications.com Vol 10(1) 7–18 Therapy Applicable to DOI: 10.1177/1359105305048549 Behaviour Change Interventions Based on the Theory of Planned Behaviour? Abstract The Theory of Planned Behaviour (TPB) is increasingly being used to inform the development of interventions to promote health behaviour change. However, although the IMOGEN C. A. HOBBIS & STEPHEN theory can be used to identify SUTTON the determinants of particular University of Cambridge, UK health-related behaviours, it offers little guidance on how to change these determinants and hence how to promote IMOGEN C. A . HOBBIS is a Clinical Psychologist and behaviour change. There is Post-doctoral Research Associate at the Institute of evidence that Cognitive Public Health, University of Cambridge. She is Behaviour Therapy (CBT) can interested in the application of clinical psychology be used to support health within health behaviour change settings and behaviour change. This article interventions. discusses the similarities and differences between the two STEPHEN SUTTON is Professor of Behavioural approaches, and considers Science at the Institute of Public Health, University of whether techniques used in Cambridge. His research interests include the CBT are applicable to application of theories of behaviour change in the interventions based on the TPB. development and evaluation of interventions to change behaviours such as smoking and physical activity. ACKNOWLEDGEMENTS. The authors are grateful to Dr Susan Michie, Professor Ann Louise Kinmonth and Wendy Hardeman for their helpful comments on an earlier draft of this manuscript. COMPETING INTERESTS: None declared. Keywords ADDRESS. Correspondence should be directed to: behaviour change interventions, I . C. A . HOBBIS, DClinPsych Programme, MED-HPP, Elizabeth Fry Building, UEA, Norwich, NR7 4TJ, UK. Cognitive Behaviour Therapy, [email: [email protected]] Theory of Planned Behaviour 7 02 048549_hobbi_(jr/t) 11/11/04 2:09 pm Page 8 JOURNAL OF HEALTH PSYCHOLOGY 10(1) Introduction health behaviours (Ogden, 2003). Second, the theory is clearly specified and there are clear THE THEORY of Planned Behaviour (TPB; published recommendations on how to measure Ajzen, 1991, 2002a) is widely used to inform the components of the theory (Ajzen, 2002b). studies to identify the predictors of behaviour, And third, there is a substantial body of particularly health behaviour (Conner & evidence supporting the theory as providing Norman, 1996). More recently, it has also been consistent prediction of intentions and, to a used to inform health behaviour change inter- lesser extent, behaviour (Armitage & Conner, ventions (Hardeman et al., 2002). However, 2001). However, although we focus on the TPB, although the TPB is consistently found to much of what we say in this article is applicable provide useful predictions of intentions and, to to other social cognition models, including stage a lesser extent, behaviour (Armitage & Conner, theories such as the Transtheoretical Model 2001; Godin & Kok, 1996; Sutton, 1998), it does (Prochaska & Velicer, 1997). Compared with not provide guidance on how to promote theories like the TPB, stage theories have a behaviour change. Other social cognition more complex structure and different impli- models, for example Social Cognitive Theory cations for intervention (Sutton, 2005; Wein- (SCT), have been shown to be successful in stein, Rothman, & Sutton, 1998). In particular, promoting change, utilizing primarily behav- they imply that interventions should be stage ioural techniques (Bandura, 1997). Such tech- matched, that is, that different interventions niques have been used for many years in other should be used depending on which stage a contexts, predominantly mental health care person is in. Techniques from CBT could be settings with people who have psychological used as part of a stage-matched intervention to difficulties. One therapeutic approach that is promote movement to the next stage in the currently attracting interest due to its reported sequence. However, in this article we focus on empirical testability, efficacy and cost-effective- the TPB. ness is Cognitive Behaviour Therapy (CBT; In sum, this article will address whether Department of Health, 2001; Nathan & certain therapeutic techniques used in CBT can Gorman, 2002; Roth & Fonagy, 1996), which offer useful additions to behaviour change inter- incorporates both behavioural and cognitive ventions based on the TPB. Before addressing techniques to support change. Given the appar- this question directly, we give a brief outline of ent success of CBT in promoting changes in each approach, and then discuss the similarities psychopathological behaviour (e.g. Clark et al., and differences between them. We devote more 1994; Whittal, Agras, & Gould, 1999), and the space to describing CBT and its underlying value of behavioural techniques in health cognitive theory than to the TPB, because we promotion interventions using SCT, it is timely assume that readers of this journal are likely to to consider whether such techniques, together be less familiar with the details of this approach. with others utilized in CBT, may be used to The description of the TPB ignores some of the promote behaviour change in interventions complexities of the theory (see Sutton, 2002a, based on the TPB. Using a CBT framework in 2004). this context rather than other therapeutic models is supported as CBT can be used to The Theory of Planned inform brief interventions, applicable to either Behaviour individuals or larger groups. This mirrors the application of the TPB to short-term, group- The TPB is an extension of the Theory of based interventions. Thus, to use CBT in this Reasoned Action (TRA; Ajzen & Fishbein, way seems feasible. 1980). According to the theory, the strength of The TPB is just one of many theories that can a person’s intention to perform a given behav- be used to predict and explain health behaviours iour is the proximal determinant of that be- and to guide behaviour change interventions. haviour (for behaviours that are at least We focus on the TPB for three main reasons. partially under the person’s control). Intention, First, it is currently the most widely used social in turn, is influenced by attitude towards the cognition model for predicting and explaining behaviour (overall evaluation of the behaviour), 8 02 048549_hobbi_(jr/t) 11/11/04 2:09 pm Page 9 HOBBIS & SUTTON: COMPARING CBT WITH THE TPB subjective norm (perceived social pressure to shown (Hardeman et al., 2002), most TPB- perform the behaviour) and perceived behav- based interventions attempt to change beliefs by ioural control (PBC, perceived control over providing information (e.g. leaflets). performing the behaviour). PBC can also The set of modal salient beliefs may not predict behaviour directly to the extent that adequately represent the salient beliefs held by perceived control accurately reflects actual individuals in the target population (Sutton, control. Underlying attitude, subjective norm 2002b; Sutton et al., 2003). Thus, in an inter- and PBC are considered to be specific beliefs, vention that targets modal salient beliefs, many referred to as behavioural beliefs, normative individuals in the target group will be presented beliefs and control beliefs respectively. Beliefs with information designed to change beliefs that salient to the individual are held to determine are not salient to them. This may limit the their attitude, subjective norm and PBC. efficacy of the intervention. According to the theory, changing behaviour An alternative approach is to elicit and requires changing these underlying beliefs. target individually salient beliefs. Each indi- (Another way of changing behaviour that is vidual would receive a different version of the suggested by the theory is to increase actual intervention, the exact content depending on control over the behaviour. However, we are his or her own idiosyncratic set of salient not aware of any TPB-based interventions that beliefs. Individually tailored interventions have used this approach.) based on the TPB are rare but they are entirely Developing an intervention based on the TPB consistent with the theory that explains behav- involves a number of steps (Fishbein & iour at an individual level. This approach is Middlestadt, 1989; Sutton, 2002b). The first step being used in the ProActive trial, an inter- is to define the target behaviour and population. vention designed to increase physical activity For example, in a physical activity intervention among people at high risk of diabetes, in which the target behaviour could be defined as walking trained facilitators are using the TPB to elicit for at least 30 minutes a day and the target and modify individuals’ beliefs about being population as sedentary adults aged 30–50. The more physically active (Hardeman et al., second step is to identify the salient behav- submitted). ioural, normative and control beliefs with respect to performing the target behaviour in a Cognitive Behaviour Therapy sample from the target population. The salient beliefs are those that first come to mind in Cognitive Therapy1 arose from Beck’s (1976) response to standard open-ended questions cognitive-behavioural hypothesis of emotion. such as ‘What would be the advantages for you This hypothesis states that emotions