Beyond the Patient: The Association Between Patient Functional Disability, Caregiver Burden, and Mental Health in Oncology

Cancer diagnosis and treatment represent a dyadic crisis, with increasing care responsibilities shifting to informal caregivers due to outpatient-oriented protocols. This study examines the multidimensional effects of patient functional disability on caregiver burden and identifies distinct predictors of anxiety and depression in caregivers of patients with advanced cancer. In this cross-sectional study, 154 patient-caregiver dyads were assessed. Patient disability was measured with the WHODAS 2.0, caregiver burden with the Caregiver Burden Inventory (CBI), and caregiver mental health with the Hospital Anxiety and Depression Scale (HADS). Multiple linear regression analyses were used to identify variables independently associated with caregiver anxiety and depression. In a cohort where 85.1% of patients had metastatic disease, caregivers exhibited high levels of psychological morbidity. Patient disability and caregiver burden were strongly associated with both anxiety and depression. Higher anxiety levels were more strongly associated with daily caregiving hours (temporal intensity; p < 0.05), whereas higher depression levels were associated with co-residence and solo caregiving (social isolation factors; p < 0.05). Caregiver burnout represents an often invisible yet clinically relevant risk factor that may negatively influence treatment adherence and oncological outcomes. Oncology practice should move beyond a tumor-centric approach and adopt a doctor-patient-caregiver triad model, recognizing caregivers as secondary patients to preserve the resilience of the support system and optimize patient outcomes.