Measuring global health-related quality of life in children undergoing hematopoietic stem cell transplant: a longitudinal study

Pediatric health-related quality of life (HRQL) measures explore multiple domains of HRQL. To ease administration, burden, and implementation, we created a 7-item unidimensional global HRQL scale for children. This paper evaluates the psychometric properties of the global HRQL scale in children undergoing hematopoietic stem cell transplant (HSCT) and describes the trajectory of global HRQL scores over the 12-month course following HSCT. As part of two longitudinal HSCT studies, HRQL was collected on 312 parent-child dyads using the Child Health Ratings Inventories. Parents of children aged 5-18 completed the pediatric global HRQL scale about their child and 117 adolescents completed the scale themselves. Psychometric properties were compared across both raters. Two repeated measures models were built to describe trajectories of (1) global HRQL for all children based on parent proxy report and (2) global HRQL for adolescents based on adolescent self-report and parent proxy report. Internal consistency reliability was high for parent proxy report and adolescent self-report (Cronbach's alpha 0.9, 0.8, respectively). Unidimensionality was verified using principal components analysis. Both models indicated decreased global HRQL in the presence of early complications related to HSCT and Model 1 further indicated decreased HRQL in the presence of later complications. Model 2 showed that parent proxies reported lower global HRQL scores than adolescent self-report. This study has demonstrated the unidimensionality and strong psychometric properties of a 7-item global HRQL scale in a sample of children undergoing HSCT. Despite its brevity, scale scores vary in clinically meaningful ways. Future applications of this scale are encouraged.