Evaluation of a Web-Based Intervention for Binge Eating Disorder

The Eating Disorders Examination Questionnaire (EDE-Q; Berg et al., 2012) captures the frequency of binge eating episodes within the last 28 days using 3 items. Higher values indicate a higher frequency of binge eating episodes.

The Eating Disorders Examination Questionnaire (EDE-Q; Berg et al., 2012) allows assessing global eating psychopathology based on 22 items. Mean scores range from 0 to 6, with higher values indicating a higher global eating psychopathology.

The Weekly Binges Questionnaire (WBQ; Munsch et al., 2007) assesses the frequency of binge eating episodes, compensatory behavior, and regular eating by asking participants to count the number of binge eating episodes, the number of compensatory behaviors, and the number of days with regular eating habits. While a higher number of binges and compensatory behaviors indicates a higher symptomatology, a higher number of regular eating days indicates a lower symptomatology.

Ecological momentary assessment (EMA) of eating disorder symptoms (shape concerns, weight concerns, binge eating episodes, urges to eat) for five days (five signal-contingent measurements and additional event-contingent assessments)

The Clinical Impairment Assessment Questionnaire (CIA; Bohn et al., 2008) consists of 16 items answered on a 4-point Likert scale. The overall score ranges from 0 to 48. Higher values indicate a higher level of clinical impairment.

The Patient Health Questionnaire (PHQ-9; Kroenke et al., 2001) consists of 9 items answered on a 4-point scale. The overall score ranges from 0 to 27. Higher values indicate a higher level of depressive symptomology.

The General Anxiety Disorder Scale (GAD-7; Spitzer et al., 2006) consists of 7 items answered on a 4-point scale. The overall score ranges from 0 to 21. Higher values indicate a higher level of anxiety symptoms.

The World Health Organization Well-Being Index (WHO-5; Topp et al., 2015) consists of 5 items answered on a 6-point scale. The overall score ranges from 0 to 100. Higher values indicate a higher level of well-being.

The Rosenberg Self-Esteem Scale (RSES; Roth et al., 2008) consists of 10 items answered on a 4-point scale. The overall score ranges from 0 to 30. Higher values indicate a higher level of self-esteem.

The iMTA Productivity Cost Questionnaire (iPCQ; Bouwmans et al., 2015) consists of 12 items grouped in general questions about paid work and questions about productivity losses in paid and unpaid work. The questionnaire captures the missed work time (paid and unpaid) in hours for short-term absence and calendar days for long-time absence and the hours of lost productivity due to presenteeism.

The Heidelberg Form for Emotion Regulation Strategies (HFERST; Izadpanah et al., 2019) consists of 28 items answered on a 5-point scale. For each of the eight emotion regulation strategies (rumination, reappraisal, acceptance, problem solving, suppression of emotional expression, suppression of emotional experience, avoidance, social support), a score ranging from 1 to 5 can be calculated. Higher values indicate a higher frequency of emotion regulation strategy endorsement.

The Difficulties in Emotion Regulation Scale (DERS; Gratz & Roemer, 2004) consists of 36 items answered on a 5-point scale. The overall score ranges from 36 to 180. Higher values indicate a higher level of emotion regulation difficulties.

Ecological momentary assessment (EMA) of affect, emotion regulation strategies and difficulties for five days (five signal-contingent measurements, and additional event-contingent assessments)

Two subscales of the Attitudes Towards Psychological Online Interventions Scale (APOI; Schroeder et al., 2015) will be used. These capture technologization threat and perceived anonymity benefits using 8 items on a 5-point scale. Higher values indicate a more positive attitude towards psychological online interventions.

The Patients' Therapy Expectation and Evaluation Scale (PATHEV; Schulte, 2008) consists of 16 items answered on a 5-point scale. The overall score ranges from 0 to 5. Higher values indicate more positive expectancies towards the therapy.

The Negative Effects Questionnaire (NEQ; Rozental et al., 2019) consists of 32 items. For each item, the participants answer whether the adverse effect occurred (yes/no), how strong the negative effect was (0 to 4) and whether they attribute the negative effect on the treatment or something else. Two scores can be obtained, one for the frequency of adverse effects due to treatment, ranging from 0 to 32, and one for the negative impact, ranging from 0 to 128. Higher values indicate a higher level of adverse effects.

The Client Sociodemographic Service Receipt Inventory - European Version (CSSRI-EU; Chisholm et al., 2000) allows assessing the number and length of using different types of healthcare services. Higher values indicate a higher number and frequency of healthcare service usage.