Assessment of health-related quality of life with the PedsQL 3.0 Cancer Module in Latvian paediatric oncology patients

Introduction: Health-related quality of life (HRQoL) assessment is an essential component of paediatric oncology care. The Paediatric Quality of Life Inventory (PedsQL) 3.0 Cancer Module is widely used to evaluate disease-specific HRQoL in children aged 2–18 years. This study assessed the reliability of the Latvian version of the module and examined HRQoL across age, diagnosis, and therapy intensity subgroups. Methods: A methodological, descriptive, cross-sectional study was conducted at the Children's Clinical University Hospital (CCUH), in Riga, from February to July 2025. Patients (2–18 years) and their parents completed the PedsQL 3.0 Cancer Module (self-report and proxy-report questionnaires). Socio-demographic and clinical data were obtained from the medical records. Results: Seventy-five children and their families were included. Internal consistencies ranged from 0.28 to 0.94, with most domains demonstrating acceptable reliability. A tendency of lower internal consistency in self-reports was observed among younger patients. No significant differences emerged between self- and proxy-reports. The range of p-values for non-significant differences in patient proxy-reports was 0.076–1.000. Lower HRQoL scores were noted for procedural anxiety in the youngest cohorts, communication and worry in 8–12-year-olds, nausea and cognitive problems in adolescents. Proxy-reports showed significantly lower physical appearance scores for central nervous system tumours versus haematological malignancies. In self-reports, higher treatment intensity was associated with lower procedural anxiety scores. Conclusions: The Latvian PedsQL 3.0 Cancer Module is a reliable tool for the assessment of HRQoL in paediatric oncology patients. Subgroup differences were modest, supporting its broad applicability in clinical and research settings.