Development of a transdiagnostic digital interactive application for eating disorders: psychometric properties,...

Given limited availability of informed treatments for people affected by eating disorders (EDs), there has been increasing interest in developing self-administered, technology-based ED interventions. However, many available interventions are limited to a specific ED diagnosis or assume that participants are ready to change. We developed a digital self-help application (called ASTrA) that was explicitly designed to be transdiagnostic and to help increase motivation for change. The aim of the present study was to describe the development and examine the psychometric properties, user satisfaction and rated potentials for practical use of our application.

The content of our application was based on concepts derived from self-determination theory, the transtheoretical model of change, and cognitive theory. The application was developed by a multidisciplinary team of clinicians, researchers, staff members and individuals with lived ED experience, each being involved in all steps of the application's development. We tested validity, reliability, satisfaction and perceived feasibility for clinical implementation in an independent sample of 15 patients with an ED and 13 clinicians specialized in ED treatment. Psychometric properties were evaluated using descriptive statistics, correlations, content validity indices and intraclass coefficients. Differences in satisfaction ratings and perceived potential for clinical implementation of the application between clinicians and patients were examined using Mann-Whitney U tests.

The digital application showed excellent validity (mean i-CVI: .93, range: .86-.96) and internal reliability (all Cronbach alpha's > .88). Patients and clinicians both considered the application acceptable, appropriate, and feasible for use in clinical practice.

Findings suggest that our transdiagnostic interactive application has excellent psychometric properties. Furthermore, patients and clinicians alike were positive about the possible use of the application in clinical practice. The next step will be to investigate the application's effectiveness as an intervention to promote autonomous motivation and to facilitate remission in people on the waitlist for specialized ED treatment.