Iris Kanera

74 Chapter 3 and several background characteristics (e.g., age, gender, education, employment status, and disease and treatment history). Finally, we measured cancer survivors’ unmet needs (Hodgkinson et al., 2007b). Power calculation Sample size calculations were based on the outcomes of QoL and psychological distress, since these were expected to be the most difficult to change. Calculations showed that 144 patients per group were required to compare means for these outcomes between groups with a power greater than .80, one sided with an alpha of .10. This was based on an expected effect size of .30 and, since recruitment would be through hospitals, a correction for multilevel analyses (intracluster correlation coefficient = .005, design effect = 1.15). With an expected dropout rate of 20% during the study, this meant 376 patients needed to be included at baseline. With 231 patients included in the intervention group and 231 patients in the waiting list control group at baseline, this target has been achieved. DISCUSSION The aim of this paper was to describe the systematic development and the study design for evaluation of the KNW, a web-based computer tailored intervention aimed at providing psychosocial and lifestyle support during life after cancer. The intervention aims to reduce cancer survivors’ experienced problems in seven areas: (1) cancer-related fatigue, (2) difficulties concerning return to work, (3) anxiety and depression, (4) relationships and intimacy issues, (5) a lack of PA, (6) a lack of healthy food intake, and (7) difficulties in preparing or maintaining smoking cessation. By reducing the experienced problems in these areas, it is expected that this ultimately will result in a higher QoL. The intervention was developed using the IM protocol (Bartholomew et al., 2011). This protocol supports health promotion program planners in systematically developing a theory and evidence- based program, and, as a result, increasing the likelihood of its effectiveness. Beside the systematic development, the KNW has several other strengths. First, since the KNW concerns a web-based intervention, it can reach many patients at once and is accessible anytime and anywhere (Lustria et al., 2009). Second, by means of tailoring, information is more personally relevant. Therefore, it is more likely that this information increases attention, is more thoughtfully processed, and facilitates behavior change or maintenance (Brug et al., 2003; de Vries & Brug, 1999; Noar et al., 2007; Rimal & Adkins, 2003). Third, the use of video material to accompany the text also increases the likelihood that the information is remembered and recalled (Bol et al., 2013; Idriss et al., 2009). Fourth, as universal methods, the KNW uses the principles of PST (Nezu et al., 1999) and CBT (Gielissen, 2007) to stimulate cancer survivors to learn self-management techniques that they also can