OBJECTIVES: The Child Health Utility instrument (CHU9D) and EQ-5D-Y are popular pediatric preference-based health-related quality of life (HRQOL) measures. This study aimed to investigate how health conditions influence dimensions of these measures by age and across time using Pediatric Quality of Life Inventory (PedsQL) data.

METHODS: We used the longitudinal study of Australian children (LSAC) data (2-18 years old). Parents reported the HRQOL for their child using the PedsQL, and whether their child had ongoing health conditions every two years. PedsQL items rated with a 5-point Likert scale were linearly transformed from 0-100. For each CHU9D dimension, we used the average of the relevant PedsQL items to represent a “CHU9D like” dimension score. Total score was the average of the dimension scores. “EQ-5D-Y like” scores were calculated similarly. We used linear mixed effects model to assess the influence of conditions on total and dimension scores. The HRQOL difference between two consecutive measurements was calculated to represent the HRQOL change across time.

RESULTS: The top 5 conditions with significant coefficients on CHU9D like total score for children 2-4 years are attention deficit disorder (ADD), frequent headache, soiling, diarrhea, and hearing problem. For 5-12 year olds, the most influential conditions are autism, anxiety/depression, ADD, epilepsy and day wetting; for 13-18 year olds they are depression, epilepsy, autism, recurrent chest pain and anxiety. The top 10 conditions in total score changes across time for 2-18 years are anxiety/depression, day wetting, recurrent abdominal pain, recurrent pain (other part), frequent headache, diarrhea, ear infection, bone/joint/muscle problem, hay fever, and ADD. The impact of different conditions varies by age and by dimensions (with expected directions). For EQ-5D-Y, the results are generally similar.

CONCLUSIONS: There are distinct and overlapping influential conditions across age and by dimension. Validation for preference-based HRQOL measures should include a range of conditions.