PhD defence W. (Wenjing) Zhou

Below is a brief summary of the dissertation:

Background:
Health-related quality of life (HRQoL) is a crucial outcome in paediatric healthcare, but validated, age-appropriate instruments are limited. This thesis evaluates the psychometric performance and clinical utility of five EuroQol instruments, namely, EQ-TIPS, EQ-5D-Y-3L, EQ-5D-Y-5L, EQ-5D-5L, and EQ-HWB-S, for measuring HRQoL in children with various health conditions and capturing spillover effects on caregivers.

Methods:
Five longitudinal studies were conducted in China, involving children with COVID-19, asthma, or haematological malignancies and their parental carers. Psychometric properties, including validity, reliability, responsiveness, and self–proxy agreement, were assessed using both self-complete and proxy-report versions. Comparative analyses of EQ-5D-5L and EQ-HWB-S were performed to evaluate caregiver spillover.

Results:
All instruments demonstrated satisfactory psychometric properties. The EQ-TIPS showed the first evidence of responsiveness in children under four years. EQ-5D-Y-3L had stronger known-groups validity and test–retest reliability compared to EQ-5D-Y-5L in paediatric asthma and cancer. Self–proxy agreement was moderate to good, although lower in emotional domains. EQ VAS was highly responsive but cognitively demanding for younger children. For caregiver assessment, EQ-5D-5L captured physical health impacts well, while EQ-HWB-S better reflected emotional and social burdens.

Conclusion:
EuroQol instruments are valid and responsive tools for assessing HRQoL in paediatric clinical populations. Selecting appropriate instruments based on age, condition severity, and context is critical. Incorporating caregiver-reported outcomes, particularly using tools like EQ-HWB-S, strengthens health technology assessments by capturing the broader impacts of child illness on families.