title: Long-term effectiveness of a combined student-parent and a student-only smoking prevention intervention among 7th grade school children in Berlin, Germany.
abstract: In Germany, the smoking prevalence among adolescents is among the highest in Europe. Our aim was to evaluate the long-term effectiveness of a combined student-parent and a student-only smoking prevention programme to reduce the smoking prevalence among 7th grade students in Berlin.
  
  
  
  Three-armed cluster-randomized controlled trial (RCT). Schools as cluster units were randomized into (i) student intervention, (ii) combined student-parent intervention or (iii) control group, with follow-up after 12 and 24 months.
  
  
  
  High schools and integrated secondary schools in Berlin, Germany.
  
  
  
  Seventh grade students aged 11-16 years. We included 47 schools, 161 classes and 2801 students [50.1% girls, mean age ± standard deviation (SD) = 13.0 ± 0.6 years].
  
  
  
  The primary outcome was self-reported regular smoking (at least one cigarette per day) after 24 months (point prevalence). Further self-reported outcomes were other smoking behaviours as well as parental rules and attitudes towards smoking. Comparisons were calculated as odds ratios (OR) with 95% confidence intervals (CI).
  
  
  
  At baseline, 2.3% of the students reported that they smoked regularly. After 24 months, 7.8% and 7.0% were regular smokers in the student-only intervention and the student-parent intervention, respectively, compared with 10.1% in the control group. The OR for being a regular smoker was 0.81 (0.34-1.92) for the student-parent intervention versus control, 0.95 (CI = 0.41-2.22) for the student-only intervention versus control and 0.85 (0.38-1.89) for student-parent intervention versus student-only intervention.
  
  
  
  A combined student-parent smoking prevention intervention delivered via secondary schools in Berlin, Germany did not result in a statistically significant reduction in regular smoking compared with a control group or a student-only intervention. The student-only intervention did not result in a significant reduction in regular smoking compared with the control group.
authors.affiliation: Institute for Social Medicine, Epidemiology and Health Economics, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Lilian
authors.initials: L
authors.lastname: Krist
authors.affiliation: Institute for Social Medicine, Epidemiology and Health Economics, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Lotz
authors.affiliation: Institute for Social Medicine, Epidemiology and Health Economics, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Christin
authors.initials: C
authors.lastname: Bürger
authors.affiliation: Institute of Nutritional Medicine, University of Hohenheim, Hohenheim, Germany.
authors.forename: Nanette
authors.initials: N
authors.lastname: Ströbele-Benschop
authors.affiliation: Institute for Social Medicine, Epidemiology and Health Economics, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Roll
authors.affiliation: Institute of Public Health, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Rieckmann
authors.affiliation: Institute of Public Health, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Müller-Nordhorn
authors.affiliation: Institute for Social Medicine, Epidemiology and Health Economics, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Stefan N
authors.initials: SN
authors.lastname: Willich
authors.affiliation: Institute for Social Medicine, Epidemiology and Health Economics, Charité-Universitätsmedizin Berlin, Berlin, Germany.|Saw Swee Hock School of Public Health, National University, 21 Lower Kent Ridge Road, Singapore.|Yong Loo Lin School of Medicine, National University, 21 Lower Kent Ridge Road, Singapore.
authors.forename: Falk
authors.initials: F
authors.lastname: Müller-Riemenschneider
mesh_terms: D000293:Adolescent; D001604:Berlin; D002648:Child; D016000:Cluster Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016487:Parenting; D010290:Parents; D012572:School Health Services; D000074606:Smoking Prevention / Q000379:methods*; D013334:Students; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
keywords: Long-term effect; parents; regular smoking; smoking prevention; students; tobacco