University College London (Davis, Hildon, Hobbs, Michie); University of Bristol (Campbell)
"Most theories applied to public health interventions tend to emphasise individual capabilities and motivation, with limited reference to context and social factors. Intervention effectiveness may be increased by drawing on a wider range of theories incorporating social, cultural and economic factors that influence behaviour."
The primary aim of this paper is to identify theories of behaviour and behaviour change of potential relevance to public health interventions across 4 scientific disciplines: psychology, sociology, anthropology, and economics. The importance of understanding the theoretical underpinnings of behavioural interventions has been highlighted in previous research suggesting theoretical bases for combining behaviour change techniques within interventions to allow synergistic effects and enhance their effectiveness. However, choosing a relevant theory can be a challenging task for intervention designers, especially given the large number of theories, many of which have the same or overlapping constructs, to choose from. Furthermore, at present, theories used in public health and behaviour change interventions more generally tend to emphasise individual and sometimes interpersonal rather than broader social and environmental variables. Current resources on theories of behaviour change tend to reflect specific contexts and disciplines, and are thus inevitably limited. The idea is that, by identifying a range of theories, it will be possible to assess which theories may be of value given the behaviour, population, and context in question.
The researchers describe the methodology of the scoping review used to identify these theories, which involved a systematic search of electronic databases, consultation with a multidisciplinary advisory group, web searching, searching of reference lists, and hand searching of key behavioural science journals. Of secondary interest, they developed a list of agreed criteria for judging the quality of the theories. The term theory was defined as: "a set of concepts and/or statements with specification of how phenomena relate to each other. Theory provides an organising description of a system that accounts for what is known, and explains and predicts phenomena". Behaviour was defined as: "anything a person does in response to internal or external events. Actions may be overt (motor or verbal) and directly measurable or, covert (activities not viewable but involving voluntary muscles) and indirectly measurable; behaviours are physical events that occur in the body and are controlled by the brain".
Through this process, the researchers identified 82 theories, which are are listed in Table 1 along with the lead author, date of the paper that originally described the theory, and the number of articles that reported using the theory. Nine defining features were identified as conceptually important for a good theory: (i) clarity of constructs; (ii) clarity of relationships between constructs; (iii) measurability; (iv) testability; (v) being explanatory; (vi) describing causality; (vii) achieving parsimony; (viii) generalisablity (across: behaviours? populations? contexts?); and (ix) having an evidence base.
The 276 articles included in the review were published between 1977 and 2012, with most of the research conducted in Europe and North America. Eighteen categories of behaviours were identified, with 3 accounting for 50% of the articles: increasing physical activity (N = 72; 26%), safe sex practices (N = 36; 13%), and smoking cessation (N = 30; 11%). Fifty-two (19%) articles addressed multiple health-related behaviours, with 17 (6%) of these targeting healthy eating and physical activity together. Of the 82 theories identified, just 4 theories accounted for 174 (63%) of articles: the Transtheoretical Model of Change (TTM; N = 91; 33%), the Theory of Planned Behaviour (TPB; N = 36; 13%), Social Cognitive Theory (SCT; N = 29; 11%), and the Information-Motivation-Behavioural-Skills Model (IMB; N = 18; 7%). A further 4 theories accounted for an additional 32 (12%) of the included articles: the Health Belief Model (HBM; N = 9; 3%), Self-determination Theory (SDT; N = 9; 3%), Health Action Process Approach (HAPA; N = 8; 3%), and Social Learning Theory (SLT; N = 6; 2%; SLT is a precursor of SCT). The remaining theories (N = 70) were applied fewer than 6 times each in the literature that met the inclusion criteria.
Reflecting on the finding that only a few of the identified theories were frequently identified in the literature, the researchers offer several explanations. For example, how often a theory is used could, in part, be confounded by the year in which the theory was introduced. Knowledge of a theory in terms of how much it is discussed in the public domain is also likely to play a role. Another explanation might be that those that are used more frequently are "better" theories and selected for use because they have a stronger evidence base or meet other quality criteria. However, frequency of use may not reflect perceived quality of the theory but, instead, fashion, familiarity, prior training, exposure, or incentivisation.
In short, the review reveals that there are a large number of theories that are of potential use in designing public health interventions. The cataloguing of 82 theories of behaviour change could be an important resource for researchers wishing to draw on theories beyond the few that currently dominate the literature. However, few of these theories have been subjected to wide-scale rigorous empirical evaluation. There have been calls for more operationalisation, application, testing, and refining of theories over many years, but advances are slow. Thus, the researchers argue that we need: more investment into methodological and substantive research in this area, designs to tease apart complex interventions, and the extent to which theories can be generalised across populations, behaviours, and contexts.
In fact, identifying the theories in this review is just the first step in a much larger and ongoing programme of work aimed at improving the use of appropriate theory and the scientific rigour with which it is applied. The next phase of the current research is to (i) investigate the connectedness of theories with each other and (ii) operationalise and demonstrate the application of the agreed 9 quality criteria. These endeavours are designed to both inform the understanding of theory and its development and help guide researchers, policymakers, and implementers of interventions on the appropriate selection and application behaviour change theories to developing public health and other behaviour change interventions.
Editor's note: Click here to access the website of the book ABC of Behaviour Change Theories: An Essential Resource for Researchers, Policy Makers and Practitioners by Susan Michie, Robert West, Rona Campbell, Jamie Brown, and Heather Gainforth. This book describes 83 theories of behaviour change (one theory was added after the publication of the article summarised above); for each theory, the book provides a brief summary, a list of its component constructs, a more extended description, and a network analysis to show its links with other theories in the book. The website includes a facility to make additions and amendments to the theory descriptions, lists of constructs, and network analyses, which can be incorporated into future editions.
From C4D Network Twitter Trawl: 26 September - 2 October 2016: Health Psychology Review, 9:3, 323-344, DOI: 10.1080/17437199.2014.941722; and ABC of Behaviour Change Theories: An Essential Resource for Researchers, Policy Makers and Practitioners website, October 20 2016. Image credit: University College London