Caregivers' proxy assessments of health-related quality of life in patients with hematologic malignancies.

OBJECTIVE: Patients with hematologic malignancies are commonly burdened by the disease itself as well as treatment-related side effects, which makes it difficult for them to complete the health-related quality of life (HRQoL) assessments. We aimed to investigate the reliability and influencing factors of caregivers as proxies in measuring HRQoL for patients with hematologic malignancies. METHODS: A total of 203 patients with hematologic malignancies and their caregivers were enrolled. Both patients and caregivers independently completed the EuroQol 5-Dimensions 5-Levels (EQ-5D-5L) questionnaire to collect patient self-rated HRQoL and caregiver proxy-rated HRQoL. Additionally, caregivers completed the Generalized Anxiety Disorder 7-Item Scale, Patient Health Questionnaire-9, and Family APGAR Index to evaluate their anxiety symptoms, depression symptoms, and perceptions of family functioning. RESULTS: The caregiver proxy-rated HRQoL exhibited strong correlations with patient self-rated HRQoL, in both EQ-5D-5L utility scores (r = 0.679, P < 0.001) and EQ-5D-5L dimensions (correlation coefficients from 0.518 to 0.695, all P < 0.001). The agreement between caregiver proxy-rated and patient self-rated EQ-5D-5L utility scores was good (ICC = 0.730, 95% CI 0.658-0.788). Exact agreement between caregiver proxy ratings and patient self-ratings ranged from 66.5% to 84.2% across EQ-5D-5L dimensions. Greater anxiety symptoms (r = 0.408, P < 0.001) or depression symptoms (r = 0.288, P < 0.001) among caregivers were significantly associated with their overestimation of patients' symptom burden. CONCLUSION: Caregivers may be reliable proxies for assessing HRQoL in patients with hematologic malignancies. However, the anxiety or depression symptoms of caregivers may increase their overestimation in patients' symptom burden.