LSHTM/Hygiene Centre for Unilever PLC

Practitioners wishing to improve behaviour for public health have a huge number of theoretical models from which to choose. Some focus at the individual psychological level, some at the level of the environment, others look at ways of separating target groups for intervention and still others propose processes aimed at designing effective interventions. Each of the approaches has strengths and weaknesses but, as yet, there is no clear evidence as to which provides the best guide to changing behaviour. In the past there have been efforts to gather theories and achieve consensus; however, these have often been uncritical and have been hampered by having no overarching view of behaviour change. In this review of approaches to behaviour change, we first set out a framework for behaviour change theories which we believe to be simple and complete. Our framework assumes that health is influenced by behaviour, that behaviour is determined by psychological entities or 'constructs' in the brain and also by the environment, and that interventions can hope to affect either, or both, brain and environment, and so affect behaviour. The framework also sets out the processes that practitioners can follow to design and evaluate behaviour change interventions. We then describe how we searched the literature for behaviour change theories and models, locating over 40 of them. We then assigned each theory to a class depending on the parts of the framework they set out to explain. Six such classes were identified: We set aside a number of approaches that did not seem appropriate to large scale behaviour change. Finally, we show that different approaches in the literature highlight different parts of the framework, and critically evaluate the different classes of approach to behaviour change. This exercise provides a number of lessons: • Though there have been attempts to review models and to reach professional consensus, such attempts have been more democratic than critical, and the solutions they offered have generally not been taken up by practitioners. • A large number of theories are concerned with the determinants of behaviour, not with the determinants of behaviour change. Understanding what causes people to behave as they currently do will not necessarily provide a good foundation for pinpointing how best 3 to get them to do something else. This is a very important distinction which seems to be widely ignored. • Though much evidence has been published for the effectiveness of interventions based …