LAUSR

Abstract Objective This study was aimed to examine patient enrolment in the pre‐intervention stage, family‐reported barriers, attendance rates and underlying predictors of short‐term attendance in a family‐system‐based randomised controlled trial for managing childhood obesity in children aged 8–12‐years‐old (ENTREN‐F). Method Psychosocial and anthropometric measures were collected through primary health referral. The data were used for descriptive analyses of sample characteristics and linear regression analyses. Results Low enrolment rates and several family‐reported barriers were observed in the pre‐intervention stage. Logistical barriers were the most frequent family‐reported reason for attrition in the different stages of the study. Having a first face‐to‐face orientation session with the families and the use of motivational interviewing helped to improve adherence in the initial phases of the study. After 6 months of intervention, family based treatments (FBTs) under consideration achieve greater adherence compared with the standard intervention. Moreover, family involvement was a predictor of success for better treatment adherence rates. By contrast, participants who attended a brief standard intervention, mothers with primary education, greater body mass index, higher levels of depressive symptomatology and more critical comments towards their children, children with higher weight status and lower levels of self‐reported depressive symptoms at baseline attended interventions less frequently. Conclusions In future programmes a comprehensive screening of modifiable factors related to family and their setting characteristics is paramount prior to intervention, identifying key barriers related to drop‐out, especially in the case of less‐advantaged families.