OBJECTIVES: The development of a child-friendly version of EQ-5D has been accelerated, but testing its psychometric in severely ill children is rare. This hampers its use in the evaluation of new cancer drugs. Moreover a new version of the instrument with 5 instead of 3 levels was developed, which increase the need for comparison of the two versions. Therefore, the aim of this study was to assess and compare the validity and responsiveness of the EQ-5D-Y (Y-3L) and EQ-5D-Y-5L (Y-5L) in paediatric patients with haematological malignancies and their caregivers.

METHODS: Paediatric inpatients with haematological malignancies and their caregivers completed the interview version of the self-classifier or proxy version of the Y-3L and Y-5L questionnaires and an overall health assessment question twice on two different days in patient wards. Known groups’ validity of the Y-3L and Y-5L dimensions, EQ VAS, LSS (level sum score) and EQ index (based on Y-3L) was assessed by comparing patients who differed in overall health, Eastern Cooperative Oncology Group (ECOG) performance, and treatment status. Responsiveness was assessed using standardized effect size (SES) or Paretian classification of change in health status.

RESULTS: Ninety-six patients (male: 64.6%; mean [range] age: 10.5 [8-17] years) and their caregivers (mother:67.7%; mean(SD) age: 40.1(9.3) years completed the baseline questionnaires. Slightly smaller proportion of the ‘no problems’ response was observed in Y-5L compared to Y-3L for most of the five dimensions. Patients in worse health reported more problems in all dimensions and had higher LSS, lower EQ VAS and index scores. The Paretian classification analysis and SESs suggested the proxy version was more responsive than the self-complete version of both instruments.

CONCLUSIONS: Both the self-complete and proxy versions of the EQ-5D-Y and EQ-5D-Y-5L questionnaires appear to be valid and responsive to measure the health outcomes of children with haematological malignancies.