Measuring caregiver outcomes in palliative care: a construct validation study of two instruments for use in economic evaluations

Purpose: Providing care to patients nearing the end of life can place a considerable burden on caregivers. Hence, policy decisions on interventions in palliative care should be guided by information on this burden. This study investigates construct validation of two preference-based caregiver outcome instruments suitable for economic evaluations: the Carer Experience Scale (CES) and the Care-related Quality of Life (CarerQol) instrument. Moreover, this study reports caregiver experiences in end-of-life care.

Methods: Data were collected with written questionnaires among caregivers of patients receiving palliative care services in the Southern metropolitan area of Adelaide, South Australia (n = 97). The effect of caregiving on caregivers was measured with the CES, CarerQol, Process Utility (PU) and Caregiver Strain Index (CSI). Convergent, discriminative and clinical validity were studied.

Results: As hypothesized, higher negative effect of caregiving measured on the CES was associated with higher negative effect on the CarerQol. Both the CES and CarerQol were associated in the expected positive direction with less strain from caregiving (CSI), more positive care experiences and more PU from caring. Caregivers’ and care recipients’ health status and duration of caregiving were negatively associated with caring experiences.

Conclusions: Our findings suggest that the CES and CarerQol validly assess the effect of caregiving on caregivers in end-of-life care. Economic evaluations in end-of-life care should attempt to incorporate such instruments to provide a more holistic assessment of the true impact of interventions, especially where family and friends are heavily involved in caregiving.