Dyadic, App-supported Collaborative Care Intervention Trial for Family Caregivers of People Living With Dementia

In Germany, approximately 84% of the five million individuals in need of care are supported at home by informal caregivers, most commonly family members. Only 21% receive professional assistance from care or support services, highlighting the substantial responsibility placed on families. People living with dementia (PlwD) constitute a particularly large share of these care recipients. On average, they require around 36 hours of informal care per week-considerably more than individuals affected by conditions such as cancer (16 hours/week) or stroke (24 hours/week). Both PlwD and their caregivers, often conceptualized as a dyad, frequently express a strong preference for remaining in their home environment and sustaining home-based care for as long as possible. While many caregivers provide support over extended periods and may even perceive their role as meaningful, the progressive cognitive and physical decline of PlwD, combined with neuropsychiatric symptoms and caregivers' perceived sense of obligation, can result in considerable psychological and physical strain. Such strain is commonly associated with depression, anxiety, diminished subjective well-being, reduced self-efficacy, and social withdrawal. Consequently, the sustainability of home care is often precarious. Indeed, 40% of caregivers of community-dwelling PlwD report being unable to maintain care for longer than one year, leading to institutionalization. Although support services for caregivers have been steadily expanded in recent years, their utilization remains limited. Barriers include a lack of awareness, organizational hurdles, and, paradoxically, the high demands of caregiving itself, which can hinder access to such services. In the absence of sufficient support, informal care is increasingly substituted by professional long-term care, thereby intensifying pressure on already limited workforce and financial resources within the health care system. This transition is also frequently accompanied by feelings of guilt among caregivers. Evidence regarding the effectiveness of interventions to support caregivers is mixed. Randomized controlled trials have only partly demonstrated significant reductions in caregiver burden. A meta-analysis indicated that individualized, structured multicomponent interventions-comprising various support modules-are most effective. While there is some evidence for cost-effectiveness, it is constrained by small sample sizes. A model-based analysis suggests that dyadic interventions, which target both PlwD and caregivers, may prolong the feasibility of home-based care and could be cost-effective. However, findings remain inconsistent: a meta-analysis of randomized controlled trials reported positive outcomes in 13 studies but no effect in 9 others. Effectiveness appears to depend strongly on the duration and intensity of interventions. One explanation may be that caregiver needs during periods of heightened burden were not adequately or promptly addressed. Digital health interventions, such as remote, app-based solutions, offer the potential to overcome these limitations by providing flexible and immediate support at critical moments. Nevertheless, research in this field remains limited, and it is still unclear to what extent digital approaches can stabilize home care situations for PlwD and their families.