Associations between advanced cancer patients' survival and family caregiver presence and burden

Abstract

We conducted a randomized controlled trial (RCT) of an early palliative care intervention (ENABLE: Educate, Nurture, Advise, Before Life Ends) for persons with advanced cancer and their family caregivers. Not all patient participants had a caregiver coparticipant; hence, we explored whether there were relationships between patient survival, having an enrolled caregiver, and caregiver outcomes prior to death. One hundred and twenty-three patient-caregiver dyads and 84 patients without a caregiver coparticipant participated in the ENABLE early versus delayed (12 weeks later) RCT. We collected caregiver quality-of-life (QOL), depression, and burden (objective, stress, and demand) measures every 6 weeks for 24 weeks and every 3 months thereafter until the patient's death or study completion. We conducted survival analyses using log-rank and Cox proportional hazards models. Patients with a caregiver coparticipant had significantly shorter survival (Wald = 4.31, HR = 1.52, CI: 1.02-2.25, P = 0.04). After including caregiver status, marital status (married/unmarried), their interaction, and relevant covariates, caregiver status (Wald = 6.25, HR = 2.62, CI: 1.23-5.59, P = 0.01), being married (Wald = 8.79, HR = 2.92, CI: 1.44-5.91, P = 0.003), and their interaction (Wald = 5.18, HR = 0.35, CI: 0.14-0.87, P = 0.02) were significant predictors of lower patient survival. Lower survival in patients with a caregiver was significantly related to higher caregiver demand burden (Wald = 4.87, CI: 1.01-1.20, P = 0.03) but not caregiver QOL, depression, and objective and stress burden. Advanced cancer patients with caregivers enrolled in a clinical trial had lower survival than patients without caregivers; however, this mortality risk was mostly attributable to higher survival by unmarried patients without caregivers. Higher caregiver demand burden was also associated with decreased patient survival.

Keywords: Advanced cancer; family caregivers; patient survival.

Figure 1

Patient survival curves by caregiver coparticipant presence/absence. Cox proportional hazards model with no covariates.

Figure 2

Adjusted survival curves by caregiver and marital status. Cox proportional hazards model adjusted for patient age, gender, and presence of an advance directive and/or durable power of attorney.

Figure 3

Adjusted survival curves by high and low caregiver burden using median split. Cox proportional hazards model adjusted for intervention group.