Intervention components and behaviour change techniques (BCTs)
Behaviour change interventions should target and address the barriers and enablers (determinants) to the target behaviour. There are multiple determinants of behaviour and thus interventions require several components to address them. Behaviour change interventions are therefore complex interventions comprising of multiple interacting components (5). Behaviour change techniques (BCTs) are the irreducible ‘active ingredients’ of a behaviour change intervention that bring about behaviour change
Selection and formulation of BCTs into tangible components that can be combined to form an intervention should be informed by evidence and behaviour change theory. Evidence provides a rich understanding of the behavioural determinants. Theory enables the behavioural mechanisms by which BCTs exert their effects to be defined. There are numerous behaviour change theories, many with overlapping constructs thus selecting any one theory to fully represent the potential determinants of a behaviour is challenging. The theoretical domains framework (TDF) is an integrative framework of behaviour change theories comprising 14 mechanisms of action domains such as knowledge , beliefs about capabilities and emotion (6) and has been successfully applied to define the behavioural mechanisms of action of deprescribing in hospital (7).
Interventions and how they are hypothesised to change behaviour and resultant outcomes can be visually depicted in a logic model. Logic models represent the causal theoretical assumptions of an intervention and moderating factors. They can also describe the context within which an intervention is implemented and how the two interact. Below we outline some of the key components of a logic model that should be tested and refined using learning from feasibility testing and evaluation processes.