Effects of a structural intervention and implementation on physical activity among youth in residential children's homes

• ENRICH had no measurable impact on residential youth physical activity.
• Process evaluation data revealed widespread implementation within control group.
• Level of implementation (high versus low) was examined for all group homes.
• Youth within high implementing homes were more physically active.
• Implementation within organizational settings is impacted by broad contextual factors.

This study reports the effects of a structural intervention, ENRICH (Environmental Interventions in Children's Homes) which targeted the physical and social environment within residential children's homes (RCHs) to increase physical activity (PA) among residents (n = 799). Participating RCHs (n = 29) were randomized to Early (n = 17) or Delayed (n = 12) groups from 2004 to 2006 and 2006 to 2008, respectively. Children's PA was measured at three time periods (2004, 2006, 2008). Intent-to-treat analysis revealed no intervention impact on PA. Subsequent analyses used process evaluation data to group organizations into high and low PA-promoting RCHs to compare PA level, controlling for assignment to condition. Organizations with high PA-promoting environments were found to have more active youth. Utility of a comprehensive implementation monitoring plan and the need for formative assessment of organizational capacity is discussed.