Iris Kanera

2 31 Prevalence and correlates of lifestyle behaviors Cancer-related measures Standard questions were used to assess cancer-related factors. Type of cancer was subsequently categorized into breast, colon, and other types; because of insufficient numbers of the separate types of cancer for appropriate statistical analyses (see footnote Table 2.3). Type of treatment was categorized into surgery alone, surgery & chemotherapy, surgery & radiation, surgery, chemotherapy & radiation, and other types for the same reason. Aftercare participation was dichotomized ( yes, no ). Information on length and weight were used to calculate the body mass index (BMI). Psychological measures Table 2.2 provides an overview of the psychological measures and their properties. QoL was assessed by using the European Organisation for Research and Treatment of Cancer (EORTC QLQ-C 30; Aaronson et al., 1993; Fayers & Bottomley, 2002; EORTC Quality of Life Group, 2001). Anxiety and depression were measured by applying the Hospital Anxiety and Depression Scale (HADS; Bjelland, Dahl, Haug, &Neckelmann, 2002; Zigmond & Snaith, 1983). Adjustment to cancer was assessed using the Mental Adjustment to Cancer Scale (MAC; Braeken et al., 2010; Watson et al., 1988; Watson & Homewood, 2008). Illness perception was assessed with the Brief Illness Perception Questionnaire (Brief IPQ; Broadbent, Petrie, Main, & Weinman, 2006; Weinman, Petrie, Moss-Morris, & Horne, 1996). The items of the latter questionnaire were adjusted to focus on recovery from cancer, and item 4 (treatment control) was deleted to achieve an acceptable internal consistency (increase Cronbach’s alpha from .61 to .75 after removing item 4). Problem solving orientation was measured by using the Short Social Problem Solving Inventory-Revised (SPSI–R: S; D’Zurilla, Nezu, & Maydeu-Olivares, 2002). Social cognitive measures Attitude, social support, self-efficacy, and intention for each lifestyle behavior were measured by using single items for the separate concepts consisting of 5-point scales with a score ranging from 1-5. Attitude was assessed with questions such as “Is it important for you to follow the nutrition guidelines?” Answer options were yes, very important (5), yes, important (4), not important / not unimportant (3), no, not important  (2), no, not at all important (1). Social support was measured by asking questions such as “To what extent do you get support from people who are important to you, to exercise sufficiently?” Response options were always (5), often (4), sometime (3), seldom (2), never (1). Self-efficacy was assessed by asking questions such as “Is it easy or difficult for you to exercise according to the guidelines?” Answering choices were very easy (5), easy (4), not difficult / not easy (3), difficult (2) very difficult (1). Intention was measured by asking questions such as “Do you intend to eat 2 servings of fruit a day in the next 6 months?” Response options were yes,