The Efficacy and Effectiveness of Online CBT - Jeroen Ruwaard

2.3. Results 23Withdrew n = 6535 did not start26 no informed consent4 incomplete screeningAppliedn = 342Pre-testn = 277Excluded n = 3816 suicidal ideation16 medication3 other counselling2 psychosis1 dissociationRandomised (1:3)n = 239Waiting-list Control n = 62Web-based CBT n = 177128 completed49 discontinued13-week Follow-up n = 611 uncontactablePost-test n = 15027 lost contactAnalyzed n = 62Analyzed n = 177Web-based CBT n = 625 did not start39 completed18 discontinuedPost-test n = 4512 unmotivated3 Year Follow-up n = 23 Year Follow-up n = 63Analyzed n = 2Analyzed n = 63Figure 2.1: Flowchart of study participation.Randomization. Because we had a fairly large sample of participants, we assignedthree times as many participants to the immediate treatment condition, while retaininga large enough sample-size in the control condition to ensure sufficient statisticalpower to detect treatment effects. Thus, 177 participants (74%) were randomlyassigned to immediate treatment, and 62 (26%) to the waiting list control condition.