Iris Kanera

210 Summary controlled trial), the follow-up period of 12 months after baseline, the low dropout rates, the advanced statistical analyses including intention-to-treat analyses, and corrections for multiple testing. There are also some limitations such as the composition of the study sample. The recommendations for future research include the investigation of the working mechanisms of the intervention, i.e., whether the effects occurred by the hypothesized changes in social cognitive factors and an expanded quantitative and qualitative evaluation related to the process of engagement in the intervention. Furthermore, future studies should focus on the determinants of behavior maintenance. Additionally, the effects of the automated referral system (MRA) could be tested more fundamentally. Importantly, after implementation of the KNW into clinical practice, the use and effects of the intervention should be followed up. In addition, a number of suggestions for improvement of the KNW are provided, including adaptations in the content and layout of the website to keep up with updates and (technical) developments. The KNW intervention can be implemented by linking the intervention to trusted websites. Moreover, the KNW can be combined with in-person guidance to address a broader group of cancer survivors. In conclusion, indications were found that having access to the web-based KNW may increase vegetable consumption and moderate physical activity after six months, while the KNWwas effective in increasingmoderate physical activity among cancer survivors younger than 57 years of age at 12 months. Despite the broad scope, relevant KNW modules were used and the intervention was highly appreciated and perceived as personally relevant. The studies in this thesis indicate the usefulness and value of the KNW to respond to the growing demand of comprehensive and personalized cancer aftercare. Overall, the fully automated KNW is applicable to a large audience and provides personalized self-management support for a broad range of problem areas that cancer survivors face after completing primary cancer treatment.