Health-related quality of life: population epidemiology and concordance in Australian children aged 11-12 years and their parents.

OBJECTIVES: To describe the distribution of health-related quality of life (HRQL) in a national sample of Australian children aged 11-12 years and their parents, and examine associations within parent-child dyads. DESIGN: The Child Health CheckPoint, a population-based cross-sectional study nested between waves 6 and 7 of the Longitudinal Study of Australian Children (LSAC). SETTING: Assessment centres in seven Australian cities and eight regional towns, or home visit; February 2015 to March 2016. PARTICIPANTS: Of all participating CheckPoint families (n=1874), 1853 children (49.0% girls) and 1863 parents (87.7% mothers) with HRQL data were included (1786 pairs). OUTCOME MEASURES: HRQL was self-reported using preference-based (Child Health Utility 9Dimension, CHU9D) and non-preference-based (Pediatric Quality of Life, PedsQL V.4.0) measures for children and preference-based measures for parents (CHU9D; Assessment of Quality of Life 8 Dimension, AQoL-8D). Utility scores from preference-based measures were calculated using existing Australian algorithms to present a score on a 0-1 scale, where 1 represents full health. Parent-child concordance was assessed using Pearson's correlation coefficients and adjusted linear regression models. Survey weights and methods were applied to account for LSAC's complex sample design, stratification and clustering within postcodes. RESULTS: Children's means and SD were 0.81 (SD 0.16) for CHU9D and 78.3 (SD 13.03) for PedsQL. In adults, mean HRQL for AQoL-8D and CHU9D were 0.78 (SD 0.16) and 0.89 (SD 0.10), respectively. Mean HRQL was similar for boys and girls, but slightly higher for fathers than mothers. The Pearson correlation coefficient for parent-child CHU9D values was 0.13 (95% CI 0.09 to 0.18). Percentiles and concordance are presented for both samples for males and females separately and together. CONCLUSIONS: We provide Australian paediatric population values for HRQL measures, and the first national CHU9D values for mid-life adults. At age 11-12 years in this relatively healthy sample, parent-child concordance in HRQL was small.