Petra Warschburger, Katja Kröller

• Background: Attrition is a serious problem in intervention studies. The current study analyzed the attrition rate during follow-up in a randomized controlled pediatric weight management program (EPOC study) within a tertiary care setting. Methods: Five hundred twenty-three parents and their 7-13-year-old children with obesity participated in the randomized controlled intervention trial. Follow-up data were assessed 6 and 12 months after the end of treatment. Attrition was defined as providing no objective weight data. Demographic and psychological baseline characteristics were used to predict attrition at 6- and 12-month follow-up using multivariate logistic regression analyses. Conclusions: The minor differences between the completers and the non-completers suggest that our retention strategies were successful. Further research should focus on prevention of attrition in families with a lower educational background.