Engagement with mental health and health behavior change interventions: An integrative review of key concepts

Low intervention engagement is common in mental health and health behavior change interventions, but research on engagement is scattered, and heterogeneity in the definition and measurement of engagement is large. To aid future engagement research, we conducted an integrative review in which we 1) discuss definitions of engagement, 2) highlight four complementary models of engagement, and 3) propose an integrative conceptual model of engagement. We searched for definitions and models of engagement in in-person, digital, and blended mental health or health behavior change interventions. Forty studies provided definitions of engagement, which were discussed and categorized. We found that most models and definitions focused on behavioral dimensions of engagement, even though our synthesis of literature indicates that engagement is a complex multidimensional, and dynamic process that consists of behavioral, cognitive, and affective dimensions. Engagement is influenced by contextual factors, such as person- and intervention characteristics, and dynamic factors, such as a person's relationship with the care provider, and motivation for treatment. Levels of engagement vary throughout the intervention process, with intervention effects reciprocally reinforcing engagement through a positive feedback loop. To guide future research on engagement, we designed an integrative conceptual model of engagement, based on existing definitions and theories that considers the complexity of engagement and is applicable in multidisciplinary contexts. Future research ideally has a multidisciplinary and contextual focus and assesses the relationship between engagement and its related constructs.