Background: Overweight and obesity in children is associated with poor health-related quality of life (HRQoL), but the nuances of this relationship across different age and socio-demographic groups are not well-established. The aim of this study is to examine how the association between weight status and HRQoL changes with age and socioeconomic position (SEP) throughout childhood and adolescence.
Methods: We used data from the Longitudinal Study of Australian Children (LSAC), a cohort study in which children were interviewed biennially from ages 4 to 17 years over seven waves of data. Measurements of HRQoL (using PedsQLTM), body mass index (BMI), and socio-demographic characteristics were collected at each interview. Of the 4983 children recruited into the study, we included data from 4083 children (a total of 24,446 observations). We used generalised estimating equations to assess whether age and SEP modified the association between weight status and HRQoL, after controlling for sex, long-term medical condition, language spoken to child and maternal smoking status.
Results: Age was a significant modifier of the association between weight status and HRQoL, with adjustment for known predictors of HRQoL (P < 0.001). At age 4, children with obesity had, on average, a 0.99 (95% CI 0.02-1.96) point lower PedsQL total score than children at healthy weight. This difference became clinically important by age 9 at 4.50 (95% CI 3.86-5.13) points and increased to 6.69 (95% CI 5.74-7.64) points by age 17. There was no evidence that SEP modified the relationship between weight status and HRQoL (P > 0.05).
Conclusions: Our results demonstrate that the relationship between overweight and obesity status and poor HRQoL is strengthened with increasing age through childhood and adolescence, but is not affected by SEP. Paediatricians, researchers and carers of children with obesity should acknowledge HRQoL outcomes, particularly for older children and adolescents.