Effectiveness of the online intervention Etendebaas.nl.

We aim to evaluate the effectiveness of Etendebaas.nl, an online intervention for female patients with bulimia nervosa, binge eating disorder and eating disorder not otherwise specified. We will conduct a randomised controlled trial with two groups: intervention group and waiting list control group. Patients in the intervention group can immediately start with the online intervention and patients in the control group have to wait 15 weeks before they can start the intervention.

The online intervention Etendebaas.nl will effectively reduce disordered eating behaviour among female patients with BN, BED and EDNOS.

T0: Baseline;

T1: Post-treatment (15 weeks);

T2: Follow-up 1 (3 months);

T3: Follow-up 2 (6 months);

T4: Follow-up 3 (one year).

In this randomised controlled trial patients will be randomised between the online intervention Etendebaas.nl (intervention group) or the waiting list control group.



Patients in the intervention group can immediately start with the online intervention. Etendebaas.nl is a structured treatment program consisting of two parts in which the patient and therapist communicate asynchronous, via the internet only. The patient and therapist are in separate locations and the interaction between them occurs with a delay between responses. The duration of the intervention varies between patients, but on average takes approximately 15 weeks. The aim of the intervention is to motivate patients to change their eating behaviour and body image, and to provide support for this change. The ultimate goal of treatment is a reduction in disordered eating behaviour. The program uses psycho-education and cognitive-therapeutic techniques. The method underlying the intervention is based on principles from the Cognitive Behaviour Therapy (CBT) and motivational interviewing. Part 1 of the intervention consists of at least seven contacts with four assignments; focusing on the analysis of the patients eating behaviour. A personal advice is given at the end of part 1. Part 2 consists of at least fourteen contacts with six assignments.



The waiting list control group receives an informational and supportive email once every two weeks during the waiting period. Patients cannot reply to these messages. These email messages include information about the website and forum of Etendebaas.nl, psycho-education, motivational messages and information related to eating disorders, such as the physical and mental symptoms.