The Efficacy and Effectiveness of Online CBT - Jeroen Ruwaard

5.2. Method 91and a measure of suicidal ideation based on the work of Joiner (Joiner et al., 2003).Medication usage was assessed through open-ended questions.Trained diagnosticians used the questionnaire data to prepare and focus a 30-minute semi-structured interview. In this interview, results of the online screeningwere discussed with the patient, after which the diagnostician decided on the eligibilityof the applicant. Excluded respondents were referred to their GPs or to mental healthcentres in their vicinity. Eligible respondents downloaded, signed and returned anInformed Consent. On receipt of this form, research assistants used the allocationsequence (which was concealed to the diagnosticians) to allocate participants to theexperimental groups.Experimental conditions Participants, allocated to online CBT, started treatmentimmediately. Participants in the bibliotherapy group received a hard-copy of Overcomingbulimia and binge eating, a Dutch self-help book for BN (Overcoming bulimia andbinge eating by Vanderlinden (2002), which is based on the same cognitive-behavioralprinciples as applied in the online treatment. Apart from an initial introductory e-mailwith instructions how to use this book, no support was provided to the participants.Participants in the waiting list control condition started online CBT after twenty weeks.Therapists The treatments were provided by graduate students in clinical psychologyor recently graduated psychologists (N = 23). All had followed advanced coursesin CBT and received additional training in administering online CBT. They weresupervised by two senior specialists in online CBT.Posttest and follow-up After 20 weeks, participants received an e-mailed invitationfor online post-test measurements. One year after the post-test, participants inthe online CBT and bibliotherapy group were similarly invited to online follow-upmeasurements. Participants in the waiting list control group completed follow-upmeasurements at a later time (i.e., one year after they had finished treatment).5.2.5 Outcome measuresPrimary outcome measures were the frequency of binge eating and purging episodesand the Eating Disorder Examination-Questionnaire (EDE-Q; Fairburn & Beglin, 1994;