Community volunteer visitation frequency shows a U shaped relationship with family caregiver burden for disabled elderly in China

This study examines the relationship between community volunteer visitation frequency and caregiver burden among Chinese family caregivers of disabled elderly individuals, with a focus on the moderating role of caregivers' mental health. A six-month longitudinal study was conducted in 30 communities (Langfang and Tai'an) with 582 primary caregivers (intervention: n = 388, control: n = 194). Caregiver burden (Zarit Burden Interview) and mental health (GHQ-12) were measured at baseline and after six months. Results revealed a U-shaped relationship: changes in caregiver burden (T2-T1) were minimized overall at 2.931 weekly visits. However, the turning points varied by caregivers' mental health status: those with poorer mental health (GHQ-12 ≥ 3) reached the minimum change in burden (ΔZBI) at 3.615 weekly visits, whereas healthier caregivers reached it at 2.607 weekly visits. Community volunteer support showed a "double-edged sword" effect: moderate visitation alleviated burden, while extremes increased stress. Caregivers' mental health moderated this effect, with those in poorer mental health benefiting from more frequent visits. The findings suggest customizing visitation frequency based on caregivers' mental health and integrating psychological support into volunteer programs.