Factors associated with health-related quality of life of informal caregivers of older patients and the mediating role of subjective caregivers' burden.

Background: Caregiving has been associated with increased subjective burden and decreased health-related quality of life (HRQOL) for caregivers. The aim of the study was to clarify the precise relationship between caregivers' burden, caregivers' HRQOL, and other risk factors, considering that subjective burden was a risk factor for poor HRQOL, which may also mediate the effects of some known risk factors.

Methods: In this cross-sectional study, patients' and their informal caregivers' characteristics were recorded for 311 patient-caregiver dyads. Subjective caregiver burden and caregivers' HRQOL were assessed using the Zarit Burden Interview and the 12-item Short-Form Health Survey (SF-12), respectively. Mediation analysis was used to examine the relationships between variables. Caregivers' mental component summary (MCS) and physical component summary (PCS) scores were regarded as outcome variables, caregivers' subjective burden was considered the mediator, and patients' and caregivers' characteristics were treated as predictors.

Results: Caregivers' subjective burden was negatively related to both PCS and MCS of caregivers' HRQOL, after controlling for the effects of demographic and clinical variables. Moreover, significant associations, mostly indirect via caregivers' subjective burden, existed between caregivers' socio-demographic characteristics, duration of caregiving, patients' frailty status, patients' co-morbidity, and caregivers' HRQOL.

Conclusion: Caregivers' subjective burden plays a major and mediating role on influencing caregivers' HRQOL. Our findings may direct future research and promote the implementation of interventions to reduce caregivers' burden and improve caregivers' HRQOL.