title: Risk moderation of a parent and student preventive alcohol intervention by adolescent and family factors: a cluster randomized trial.
abstract: OBJECTIVE
  To examine risk moderation of an alcohol intervention targeting parents and adolescents.
  
  
  METHODS
  A cluster randomized trial including 2937 Dutch early adolescents (m=12.68years, SD=0.51) and their parents randomized over four conditions: parent intervention, student intervention, combined parent-student intervention, and control group.
  
  
  METHODS
  152 classes of 19 high schools in The Netherlands (2006).
  
  
  METHODS
  Moderators at baseline (adolescent: gender, educational level and externalizing behavior; parent: educational level and heavy alcohol use) were used to examine the differential effects of the interventions on onset of (heavy) weekly drinking at 22-month follow-up.
  
  
  RESULTS
  The combined intervention effectively delayed the onset of weekly drinking in the general population of adolescents, and was particularly effective in delaying the onset of heavy weekly drinking in a higher-risk subsample of adolescents (i.e. those attending lower levels of education and reporting higher levels of externalizing behavior).
  
  
  CONCLUSIONS
  Present and previous results have established the combined intervention to be universally effective in postponing weekly alcohol use among Dutch adolescents, with an added effect on postponing heavy weekly drinking in high risk subgroups. Therefore, implementation of this intervention in the general population of schools in The Netherlands is advised.
  
  
  BACKGROUND
  NTR649.
authors.affiliation: Trimbos Institute, Netherlands Institute of Mental Health and Addiction, P.O. Box 725,3500 AS Utrecht, The Netherlands.
authors.forename: Jacqueline E E
authors.initials: JE
authors.lastname: Verdurmen
authors.affiliation: Child and Adolescent Studies, Utrecht University, P.O. Box 80.140, 3508 TC Utrecht, The Netherlands. Electronic address: i.koning@uu.nl.
authors.forename: Ina M
authors.initials: IM
authors.lastname: Koning
authors.affiliation: Child and Adolescent Studies, Utrecht University, P.O. Box 80.140, 3508 TC Utrecht, The Netherlands.
authors.forename: Wilma A M
authors.initials: WA
authors.lastname: Vollebergh
authors.affiliation: Child and Adolescent Studies, Utrecht University, P.O. Box 80.140, 3508 TC Utrecht, The Netherlands.
authors.forename: Regina J J M
authors.initials: RJ
authors.lastname: van den Eijnden
authors.affiliation: Behavioural Science Institute, Radboud University Nijmegen, P.O. Box 9104, 6500 HE Nijmegen, The Netherlands.
authors.forename: Rutger C M E
authors.initials: RC
authors.lastname: Engels
mesh_terms: D000293:Adolescent; D000428:Alcohol Drinking / Q000453:epidemiology / Q000517:prevention & control*; D002648:Child; D016000:Cluster Analysis; D005191:Family Characteristics; D005260:Female; D005500:Follow-Up Studies; D040261:Harm Reduction; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D008297:Male; D009426:Netherlands; D010290:Parents; D012307:Risk Factors; D012572:School Health Services / Q000458:organization & administration*; D013334:Students
keywords: Alcohol use; Early adolescents; Intervention; Moderation; Parents; Randomized trial