An ontology of mechanisms of action in behaviour change interventions

Abstract

Background: Behaviour change interventions influence behaviour through causal processes called “mechanisms of action” (MoAs). Reports of such interventions and their evaluations often use inconsistent or ambiguous terminology. This includes the reporting of MoAs, creating challenges for searching, evidence synthesis and theory development. An ontology can help address these challenges by serving as a classification system that labels and defines classes for MoAs and their relationships. Aim: To develop an ontology of MoAs of behaviour change interventions.Methods: To develop the MoA Ontology, we (1) defined the ontology’s scope; (2) identified, labelled and defined the ontology’s classes; (3) refined the ontology by annotating (i.e., coding) MoAs in intervention reports; (4) refined the ontology via stakeholder review of the ontology’s comprehensiveness and clarity; (5) tested whether researchers could reliably apply the ontology to annotate MoAs in intervention reports; (6) refined the relationships between classes; (7) reviewed the alignment of the MoA Ontology with relevant ontologies, (8) reviewed the ontology’s alignment with the Theories and Techniques Project; and (9) published the ontology and created a machine-readable version.Results: An MoA was defined as “a process that is causally active in the relationship between a behaviour change intervention scenario and its outcome behaviour”. We created an initial MoA Ontology with 261 classes through Steps 2-5. Inter-rater reliability for annotating study reports using these classes was α=0.68 (“acceptable”) for researchers familiar with the ontology and α=0.47 for researchers unfamiliar with it. As a result of additional revisions (Steps 6-8), 21 further classes were added to the ontology resulting in 282 classes organised into seven hierarchical levels.Conclusions and implications: The MoA Ontology extensively captures MoAs of behaviour change interventions. The ontology can serve as a controlled vocabulary for MoAs to consistently describe and synthesise evidence about MoAs across diverse sources.