Iris Kanera

134 Chapter 6 fit with the increasing demand for online health-related information, may stimulate self- care, and might complement a stepped care approach within cancer aftercare (Aaronson et al., 2014; Chou et al., 2011; Given & Given, 2013; Krebber et al., 2012; Runowicz et al., 2016). Although a growing number of web-based self-management interventions have been developed for cancer survivors in recent years, only a few web-based studies evaluated PA and/or diet outcomes (Bantum et al., 2014; Goode et al., 2015; Kim & Park, 2015; Kuijpers et al., 2013; Lee et al., 2014). Post intervention increases in moderate PA and/or vegetable intake have been reported, however, behavior change was not maintained at 6-month follow-up (Bantum et al., 2014; Lee et al., 2014; Rabin, Dunsiger, Ness, & Marcus, 2011; Valle, Tate, Mayer, Allicock, & Cai, 2013). Although younger, female, and higher educated survivors often participated in web-based interventions, it is unknown whether and which possible subgroups of cancer survivors might benefit most from web-based lifestyle interventions (Kohl et al., 2013). This can be important knowledge to integrate web-based interventions into cancer aftercare. The web-based intervention Kanker Nazorg Wijzer (Cancer Aftercare Guide, KNW) is a computer-tailored intervention that ultimately aims to increase survivors’ QoL (Willems et al., 2015). The online portal comprises eight separate modules that target the topics PA, diet, smoking cessation, return-to-work, fatigue, anxiety and depression, social relationships, and residual problems. Survivors of various types of cancer had access to the fully automatedweb portal for six months. Previously reported findings revealed strong indications that having access to the KNW may account for meaningful increases in moderate PA and vegetable consumption after six months of access, while using the behavior specific modules accounted for higher increases of moderate PA and higher fruit and fish consumption (Kanera et al., 2016b). The aim of the present study is to examine the long-term (12-month) effects of the web- based KNW on moderate PA and vegetable consumption, in order to evaluate whether the KNW outcomes on moderate PA and vegetable intake that were found six months after the baseline measurement were maintained in the long term. In addition, we explored whether possible effects on the behavioral outcomes (i.e. moderate PA, vegetable intake) were influenced by whether or not participants visited the module that was directed at the behavior in question. This procedure was in line with the 6-month evaluation (Kanera et al., 2016b). To identify possible subgroups that might benefit most from this intervention, we explored whether a possible intervention effect was moderated by gender, age, and educational level.