Development of a digital therapeutic alliance scale (MM-DTA) in the context of fully automated mental health apps

Therapeutic alliance (TA) refers to the relationship between a therapist and a client in face-to-face therapy and is an essential ingredient in successful psychological therapy outcomes. With the availability of fully automated apps, the question arises as to whether there is an analogous notion of a digital therapeutic alliance (DTA), and whether and how it plays a role in usage and outcomes of digital health interventions. Recent work has demonstrated that the DTA comprises five dimensions. Through a two-phase process, we have developed a preliminary scale to quantitatively capture this conceptualisation. Phase 1 described the process of scale development and involved three steps: item generation; content validity establishment; and face validity establishment. Phase 2 was a pilot test of the scale in two studies: a cross-sectional survey of mindfulness apps (sample size, <i>n</i> = 542), and a 30-day study with an evidence-based mental health app (sample size, <i>n</i> = 58). Reliability was assessed using internal consistency and intra-class correlation. We also explored convergent, predictive, and discriminant validity. Following the two phases, we developed a 39-item DTA scale that is reliable and demonstrates good face, content and convergent validity. This new DTA scale, grounded in people's experiences of using mental health apps, provides a valuable tool for evaluating mental health apps. <b>Highlights</b>Our new 39-item scale, MM-DTA, is grounded in people's experiences of using mental health apps.MM-DTA is reliable and demonstrates good face, content, and convergent validity.MM-DTA can be used to evaluate mental health apps and explore mechanisms of change in digital health interventionsit is important to continue to evaluate the MM-DTA in relation to a range of different mental health apps and with different populations of app users. Our new 39-item scale, MM-DTA, is grounded in people's experiences of using mental health apps. MM-DTA is reliable and demonstrates good face, content, and convergent validity. MM-DTA can be used to evaluate mental health apps and explore mechanisms of change in digital health interventions it is important to continue to evaluate the MM-DTA in relation to a range of different mental health apps and with different populations of app users.