Iris Kanera

7 165 General Discussion To avoid Type 3 error (evaluating a program that has not been adequately implemented; Basch, Sliepcevich, Gold, Duncan, & Kolbe, 1985), we checked whether the modules were used. As mentioned before, the MRA was followed to a large extent. Moreover, almost all module users continued using the modules after reading the first three compulsory pages of the modules, suggesting that attrition regarding the intervention use was relatively low. Besides, also other intervention elements were used (news items, forum) that were not included in the referral algorithm. Accessibility of the KNW An important strength of the KNW is that it is accessible to cancer survivors with different personal and cancer-related characteristics such as levels of education, gender, type of cancer, and cancer treatment. Importantly, the educational level of the participants (i.e., low, medium, and high) was evenly distributed and seemed unrelated to effects, use, appreciation, and perceived personal relevance of the KNW. Accordingly, the intervention is usable, appreciated, and effective among a diverse audience. Study design A RCT was conducted to identify effects of the KNW on lifestyle behaviors, which was an important strength of the studies (Chapter 5 and Chapter 6). This study design, consisting of an intervention condition and a usual care waiting list control group was ethically the most appropriate to investigate the main effects of the novel and comprehensive intervention (Cunningham, Kypri, & McCambridge, 2013). The two-armed experiment entailed a valid randomization method (built-in digital randomizer) and concealment of allocation sequence was maintained until informed consent was obtained and revealed when participants logged in for the first time. After randomization, participants received information about the moment when they could access the program. Terminology concerning intervention- or control group was avoided. Blinding of participants and researchers to the intervention arm was not possible, which may be a limitation, although researchers could not influence the online self-reported assessments and the intervention itself. Another weakness might be that all participants potentially could have been exposed to other forms of online information (co-interventions); searching for information was not prohibited. However, the use of co-interventions was assessed and did not differ between study groups. Contamination between the two intervention conditions was unlikely, given the online and personalized protected delivery mode and the national outstretched recruitment of participants.