Esther Mertens

78 | Chapter 4 and did not deviate much from the manual (72%). Three R&W experts observed 67 R&W lessons and reported that most observed lessons were (almost) completed (86%), trainers did not deviate much from the manual (91%), and adjustments were seen as improvements (62%). In conclusion, the intervention was implemented withmoderate to high fidelity to the manual. Control. Care as usual differed between the schools. In one school, it entailed teachers as personal coaches. Adolescents had regular meetings, discussed their wellbeing, and got advice from their coach. In a second school it entailed that adolescents participated in a project week ‘being different’, had class discussions about bullying, signed an anti-bullying contract, and had a mentor (teacher) they could contact if they experienced difficulties. Another school had appointed an ‘anti-bullying coordinator’ who organized activities to prevent or stop bullying and adolescents had a mentor (teacher) they could contact if they experienced difficulties. Outcomes Intrapersonal domain Psychological wellbeing. The presence of positive emotions was measured with the subscale Psychological wellbeing of the KIDSCREEN-27 (Ravens-Sieberer & The European KIDSCREEN Group, 2006). The subscale contains 7 items (e.g., “Past week, have you been in a good mood?”) answered on a 5-point Likert-type scale (1 = never to 5 = always ). Some items were recoded with higher scores indicating more psychological wellbeing (Cronbach’s α = .76 - .83). Resilience. The ability to bounce back from challenges that can arise in life was measured with the Connor-Davidson Resilience Scale – short version (Davidson & Connor, 2017). The questionnaire contains 10 items (e.g., “Can deal with whatever comes.”) answered on a 5-point Likert-type scale (0 = not true at all to 4 =  true nearly all the time ; Cronbach’s α = .79 - .92). Sexual autonomy. Coping skills in sexual situations was measured with 5 items from the study Sex under 25 (e.g., “When I am with someone I like, I feel at ease.”; De Graaf, Meijer, Poelman, & Vanwesenbeeck, 2005) answered on a 4-point Likert-type scale (1 = never to 4 = always ). Some items were recoded with higher scores indicating more sexual autonomy. Reliability was poor at T1 (Cronbach’s α = .53) and adequate at T2, T3, and T4 (Cronbach’s α = .62 - .65). Internalizing behavior. The presence of internalizing problems was assessed using the internalizing subscale of the short version of the Youth Self Report (YSR; Chorpita et al., 2010). The subscale contains 6 items (e.g., “I feel worthless.”) answered on a 3-point Likert-type scale (0 = never to 2 = often ; Cronbach’s α = .79 - .86).