Moderators of change in an Internet-based intervention for eating disorders with different levels of therapist support: What works for whom?

Publication Type:

Journal Article


Behaviour Research and Therapy, Volume 89, p.66-74 (2017)



E-Health; Internet-based; Eating disorders; Anorexia nervosa; Bulimia nervosa; Therapist support; Moderators


This study investigated moderators of intervention response in a fully automated Internet-based
monitoring and feedback intervention (‘Featback’) with different levels of therapist support for individuals
with eating disorder (ED) symptoms. This study was part of a randomized controlled trial
comparing four conditions: 1) Featback, 2) Featback with low-intensity (weekly) therapist support, 3)
Featback with high-intensity (three times a week) therapist support, and 4) a waiting list. A total of 273
participants completed baseline and post-intervention assessments. The outcome measure was ED
psychopathology. Model-based recursive partitioning was applied. Baseline levels of ED psychopathology
were found to moderate intervention response. Specifically, in terms of improvement in symptoms of
anorexia nervosa, participants with higher baseline levels of anorectic psychopathology showed better
outcomes in the waiting list condition and the Featback conditions with low- and high-intensity therapist
support in comparison with Featback without therapist support. In terms of improvement in
symptoms of bulimia nervosa, participants with mild to moderate bulimic symptoms had better outcomes
in the Featback conditions compared with the waiting list. Thus, the fully automated Internetbased
intervention with and without therapist support may be particularly suitable in improving mild
to moderate bulimic psychopathology, whereas the intervention without therapist support may be less
effective in improving severe anorectic psychopathology. Further investigating differential intervention
responses is important, as this could help to optimize the delivery and dissemination of E-health interventions
and therapist support, which in turn could help moving toward personalized (E-)care.