Supported online cognitive behavioural therapy for bulimia nervosa: a study protocol of a randomised controlled trial.

Background: Despite the availability of effective treatments for bulimia nervosa (BN), a number of barriers to accessibility exist. Examples include access to trained clinicians, the expense of treatment, geographical limitations, and personal limitations such as stigma regarding help seeking. Self-help interventions, delivered via a digital platform, have the potential to overcome treatment gaps by providing patients with standardised, evidence-based treatments that are easily accessible, cost-effective, and require minimal clinician support. Equally, it is important to examine the shortcomings of digital interventions when compared to traditional to face-to-face delivery (e.g., high dropout rates) in order to maximise the therapeutic effectiveness of online, self-help interventions.

Methods: A three-arm, multisite randomised controlled trial will be conducted in Australia examining the effectiveness and cost-effectiveness of a newly developed online self-help intervention, Binge Eating eTherapy (BEeT), in a sample of patients with full or sub-threshold BN. The BEeT program consists of 10, multimedia sessions delivering the core components of cognitive behaviour therapy. Eligible participants will be randomised to one of three groups: independent completion of BEeT as a purely self-help program, completion of BEeT alongside clinician support (in the form of weekly telemedicine sessions), or waitlist control. Assessments will take place at baseline, weekly, post-intervention, and three-month follow up. The primary outcome is frequency of objective binge episodes. Secondary outcomes include frequency of other core eating disorder behavioural symptoms and beliefs, psychological distress, and quality of life. Statistical analyses will examine treatment effectiveness, feasibility, acceptability and cost effectiveness.

Discussion: There is limited capacity within the mental health workforce in Australia to meet the demand of people seeking treatment for eating disorders. This imbalance has only worsened following outbreak of the COVID-19 pandemic. Further research is required into innovative digital modes of treatment delivery with the capacity to service mental health needs in an accessible and affordable manner. Self-help programs may also appeal to individuals who are more reluctant to engage in traditional face-to-face treatment formats. This study will provide rigorous evidence on how to diversify treatment options for individuals with BN, ensuring more people with the illness can access evidence-based treatment. The study has been registered with the Australia New Zealand Clinical Trials Registry (ANZCTR Registration Number: ACTRN12619000123145p). Registered 22 January 2019, https://www.australianclinicaltrials.gov.au/anzctr/trial/ACTRN12619000123145 .