The Long‐Term Effects of a Combined Physical Activity and Health Education Programme on Well‐Being for Socially Vulnerable Children and Adolescents

Childhood and adolescence are critical periods for the development of well-being, yet declines are commonly observed, particularly among youth from low socio-economic status backgrounds. This study examined the short-term (3.5 months) and long-term effects (16 months) on well-being of a residential multicomponent health promotion intervention at the Danish Christmas Seal Homes (DCSH), with and without the addition of the 11 for Health (11fH) programme. A randomized crossover design compared a Standard group (DCSH, n = 237) to a Standard+ group receiving the residential stay plus 11fH (combined football and health education sessions, n = 244). Well-being was assessed using the Pediatric Quality of Life Inventory (PedsQL 4.0 Generic) and KIDSCREEN-27. Multilevel modeling evaluated changes in well-being outcomes over time, accounting for repeated measurements nested within individuals. Participants in both groups reported well-being scores at or above normative values post-intervention, with these largely maintained at short- and long-term follow-ups. No significant group differences emerged over time. Physical Well-being declined over time, while Physical Functioning improved at short-term follow-up, but the increase was not sustained at the long-term follow-up. Females reported lower scores than males across several domains, including Physical Functioning, Emotional Functioning, Physical Well-being, and Psychological Well-being. Older age and higher pre-intervention scores were associated with lower well-being improvements. The results suggest that health-promoting interventions delivered in residential settings can help sustain well-being for socially vulnerable children. Moreover, consistent sex differences point to the need for ongoing support and tailored approaches for females. Trial Registration: This is a secondary analysis of a clinical trial, which has been registered on August 24, 2018: ClinicalTrials.gov ID: NCT03647007.