Treatment Effectiveness of PMTO for Children's Behavior Problems in Iceland: Child Outcomes in a Nationwide Randomized Controlled Trial.

Well-documented treatment methods must be tested following their implementation in community service agencies and across different cultures to ensure continuing effectiveness. This study was a randomized controlled trial (RCT) of Parent Management Training-the Oregon model (PMTO), conducted within a nationwide implementation in Iceland. Families of 102 clinically referred children with behavior problems were recruited from five municipalities throughout Iceland. Child age ranged from 5 to 12; 73% were boys. Families were randomly assigned to either PMTO or services usually offered in the communities (SAU). Child adjustment was measured with a latent construct based on parent, child, and teacher reports of externalizing and internalizing problems and social skills. Prepost intent-to-treat analyses showed that PMTO treatment led to greater reductions in child adjustment problems relative to the comparison group, obtaining a modest to medium effect size based on the construct score. Only one indicator (parent-rated Social Skills) showed significant change independently and information on amount and kind of treatment in the SAU was limited. Overall, findings indicate that PMTO is an effective method to treat children's behavior problems in a Northern European culture and supply evidence for the method's successful implementation in community settings in Iceland. This is one of few nationwide implementation studies of PMTO outside the United States and the first RCT in Iceland to test a treatment model for children's behavior problems.