Randomised Controlled Trial on the effectiveness of the online intervention Etendebaas.nl, for female patients with bulimia nervosa, binge eating disorder and eating disorder not otherwise specified.

Disordered eating behaviour and body dissatisfaction are very prevalent among
the Dutch population, but are frequently unnoticed. Only few people who are
concerned about their eating habits seek professional care. People who do seek
care often have had complaints for many years, causing an increase in problems.
The threshold for seeking professional care is often high and there is a need
for easily accessible low threshold care. In 2005 Tactus Verslavingszorg
introduced the online intervention Alcoholdebaas.nl for people with an alcohol
problem. In view of the positive results of this low threshold from of online
treatment, Tactus, in 2009, also developed the online intervention
Etendebaas.nl for people with an eating disorder.

Although online interventions have proved to be effective not only for people
with alcohol problems, but also for people with depressions and fear related
complaints, the effects of Etendebaas.nl have not yet been scientifically
proven. A recently conducted pilot study did find that participants were
positive about the intervention and would recommend the intervention to others.
The pilot study also showed other positive effects like a significant
improvements in eating behaviour and a more positive body image. However, to
scientifically assess the effectiveness of this online intervention this
randomized controlled trial will be conducted.

The aim of the study is to investigate the effectiveness of the online
intervention Etendebaas.nl for female patients with bulimia nervosa (BN), binge
eating disorder (BED) and eating disorder not otherwise specified (EDNOS).

The research questions of this study are:
1. Is the online intervention Etendebaas.nl effective in terms of reducing
disordered eating behaviour among female patients with BN, BED and EDNOS?
2. Is the online intervention Etendebaas.nl for patients with BN, BED and EDNOS
effective in terms of improvement of body dissatisfaction, physical health,
body weight, mental health, self-esteem, quality of life, social contacts,
motivation for treatment, helping alliance and patients* satisfaction with the
intervention and their therapist?
3. Does the reduction in disordered eating behaviour and the improvement of
body dissatisfaction, physical health, body weight, mental health, self-esteem,
quality of life and social contacts, remain after 3, 6 and 12 months?
4. Do the following characteristics of patients have a predictive value on the
effectiveness of the online intervention Etendebaas.nl: demographics, Body Mass
Index, type of eating disorder, motivation for treatment, degree of
alexithymia, medication use, substance abuse, previous help for eating
disorders and previous help for mental or emotional problems?
5. How many patients terminate the online intervention Etendebaas.nl
prematurely and what are predictors for premature termination?
6. What is the additional value of participating in the online forum of
Etendebaas.nl in terms of reducing disordered eating behaviour and improvement
of body dissatisfaction, physical health, body weight, mental health,
self-esteem, quality of life and social contacts?

This study will be conducted as a randomised controlled trial, in which
patients will be randomised between the online intervention Etendebaas.nl
(intervention group) or the waiting list control group. Patients in the
intervention group can start immediately with the online intervention. Patients
in the waiting list control group have to wait 15 weeks before they can start
the online intervention. During this period the patients in the control group
receive an informational and supportive email once every twee weeks, to keep
them involved in the study.

After randomization, 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. Patient and therapist are in separate
locations and the interaction between the therapist and patient occurs with a
delay between responses. De 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 and body dissatisfaction. The
program uses psycho-education and cognitive-therapeutic techniques. The method
underlying the intervention is based on principles form 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. Part 2 starts with setting goals to eating, exercising, weighting
and if applicable compensation.

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.

Patients in the waiting list control Group have to wait 15 weeks before they
can start with the online intervention. During these period they receive
informational and supportive email messages, once every two weeks.

The burden of the randomised controlled trial for patients is minimal and
consists of an extension of five existing questionnaires (intake, in-between
measurement, post-test, follow-up 3 months (regular intervention 6 weeks) and
follow-up 6 months) and two additional questionnaires: (1) follow-up 12 months
for both groups and (2) extra questionnaire for those patients in the
intervention group who have not finished the intervention 18 weeks after
randomization or extra questionnaire for patients in the control group just
before they can start the online intervention (after a waiting period of 15
weeks).