Context: Quality of life (QoL) and depression are important patient-reported outcomes in cancer care. However, the relative importance of depression severity in predicting QoL remains unclear due to few methodologically sound studies.
Objectives:To examine whether depression contributes to impairment of QoL irrespective of prognostic factors and symptom burden.Methods: 563 patients were included from the European Palliative Care Research Collaborative Study (EPCRC-CSA), an international, multi-centre, cross-sectional study. The relative importance of prognostic factors (systemic inflammation (mGPS), co-morbidities and physical performance (KPS), symptom burden (loss of appetite, breathlessness, nausea (ESAS) and pain (BPI)) and depression severity (PHQ-9) in predicting Global Health/QoL (EORTC-QLQ-C30) were assessed using hierarchical multiple regression models.Results: 55% were females, median age 64 years, 87% had metastatic disease,
Conclusion:Depression severity was the strongest single predictor of poorer QoL in this sample of patients with advanced cancer, after accounting for a wide range of clinically relevant variables. Future studies should investigate the contribution of psychosocial variables on QoL. Our findings emphasize the importance of managing depression to achieve the best possible QoL for these patients.