Validity and responsiveness of EQ-5D-Y in children with haematological malignancies and their caregivers.

The psychometric properties of the EQ-5D-Y have not been widely tested in severely ill children. The aim of this study was to assess and compare the validity and responsiveness of the EQ-5D-Y-3L and EQ-5D-Y-5L in paediatric inpatients with haematological malignancies and caregivers. Respondents completed the interviewer-administered self-complete or proxy version of the EQ-5D-Y-3L and EQ-5D-Y-5L and an overall health assessment twice on different days. Known-groups validity was assessed by comparing patients who differed in overall health and Eastern Cooperative Oncology Group (ECOG) performance. Responsiveness to worsened health was assessed using standardised effect size (SES) for patients with worsened ECOG grade, self-reported rating, or chemotherapy initiation. Ninety-six dyads completed the baseline questionnaires. A smaller proportion of patients reported "no problems" on the EQ-5D-Y-5L compared to EQ-5D-Y-3L for most of the five dimensions. Patients in poor health reported more problems in all dimensions and had higher EQ-5D-Y-5L level sum score, lower EQ VAS and EQ-5D-Y-3L index scores (Cohen's d ES: 0.32-1.38 for patients; 0.50-2.05 for caregivers). There was a mild to good responsiveness to worsened health condition based on ECOG (SES: 0.14-0.61 for patients; 0.40-0.96 for caregivers), suggesting the proxy version was slightly responsive than the self-complete version of both instruments. The results demonstrated validity and responsiveness for both the self-complete and proxy versions of the EQ-5D-Y-3L and EQ-5D-Y-5L. The proxy and 5-level versions of the instrument were more sensitive than the self-complete and 3-level versions in this patient group.