Background: Behavioural parent training is effective in improving child disruptive behavioural problems in preschool children by increasing parenting competence. The indicated Prevention Programme for Externalizing Problem behaviour (PEP) is a group training programme for parents and kindergarten teachers of children aged 3–6 years with externalizing behavioural problems. Aims: To evaluate the effects of PEP on child problem behaviour, parenting practices, parent-child interactions, and parental quality of life. Method: Parents and kindergarten teachers of 155 children were randomly assigned to an intervention group (n = 91) and a nontreated control group (n = 64). They rated children's problem behaviour before and after PEP training; parents also reported on their parenting practices and quality of life. Standardized play situations were video-taped and rated for parent-child interactions, e.g. parental warmth. Results: In the intention to treat analysis, mothers of the intervention group described less disruptive child behaviour and better parenting strategies, and showed more parental warmth during a standardized parent-child interaction. Dosage analyses confirmed these results for parents who attended at least five training sessions. Children were also rated to show less behaviour problems by their kindergarten teachers. Conclusions: Training effects were especially positive for parents who attended at least half of the training sessions. Abbreviations: CBCL: Child Behaviour Checklist; CII: Coder Impressions Inventory; DASS: Depression anxiety Stress Scale; HSQ: Home-situation Questionnaire; LSS: Life Satisfaction Scale; OBDT: observed behaviour during the test; PCL: Problem Checklist; PEP: prevention programme for externalizing problem behaviour; PPC: Parent Problem Checklist; PPS: Parent Practices Scale; PS: Parenting Scale; PSBC: Problem Setting and Behaviour checklist; QJPS: Questionnaire on Judging Parental Strains; SEFS: Self-Efficacy Scale; SSC: Social Support Scale; TRF: Caregiver-Teacher Report Form

Background: The long-term effectiveness of parent training for children with externalizing behaviour problems under routine care within the German health care system is unclear. We report the 1-year follow-up results of the parent training component of the Prevention Program for Externalizing Problem Behaviour (PEP) for 270 children aged 3–10 years with externalizing behaviour problems. Method: Outcome measures included child behaviour problems (externalizing behaviour problems, Attention-Deficit/Hyperactivity Disorder symptoms and Oppositional Defiant Disorder symptoms) and parenting (self efficacy of parenting and perceived ability to solve difficult parenting situations). Data were analysed using multilevel modelling. Results: Comparison of the changes during the 3-month waiting and treatment periods revealed significantly stronger treatment effects on all outcome measures, indicating a substantial decrease in child behaviour problems and a significant increase in parenting due to treatment. At 1-year follow-up, initial treatment effects on child behaviour problems were maintained, while parenting continued to improve. Conclusions: Families whose children exhibited externalizing problem behaviour profit from PEP and improvements are maintained for at least one year.