Multicomponent interventions, by definition, employ a variety of methodologically distinct approaches to address caregiver needs. The intent underlying the use of multicomponent interventions is to recognize that the complexity of caregiving issues is best addressed by a variety of components rather than just one. The heterogeneity of interventions subsumed by this category, therefore, has made it somewhat more difficult to analyze than more homogenous/intervention types. For example, even though Parker et al (2008) recognize that the majority of multicomponent interventions studies they identified showed a significantly positive effect, these studies could not be pooled for meta-analysis. Coon et al (2009) highlighted an intervention that demonstrated significant positive effects on depressive symptoms that persisted for 3 years after an intervention. Conversely, Pinquart & Sørensen (2006) were able to pool studies and found that multicomponent interventions significantly influenced the time required for a CR to be institutionalized, but that these interventions had no effect on burden, depression, SWB, CR symptoms or caregiver knowledge/awareness. The caution in looking at multicomponent interventions in the meta-analysis rests in the variability of the structure and delivery of the components. The findings from Pinquart & Sørensen (2006) are contrasted with a multi-site multicomponent caregiver intervention known as the Resources for Enhancing Alzheimer’s Caregivers Health (REACH) study.
REACH was a landmark multi-site randomized clinical trial designed to test the effectiveness of several different caregiver interventions and then analyze the pooled effects. According to Schulz (2005) “this research program was able to link specific elements of a multicomponent intervention to caregiver outcomes, showing that interventions that actively engage the caregiver in skill acquisition aimed at regulating their own behavior result in significant improvements in caregiver depression.” Thus, the outcomes that multicomponent interventions impact may vary depending on the particular mix of components – a point that highlights the importance of being able to assess the strength of intervention evidence for sources of bias or error.
Aside from identifying specific programs that demonstrated positive effects on burden and depressive symptoms in certain populations, the key finding was that interventions should be able to respond to varying needs of caregivers and therefore be tailored, wherever possible, to the individual. The initial REACH I trial gave rise to a follow up randomized clinical trial, REACH II, which used a multicomponent approach to addressing caregiver needs in an adaptive framework (Belle et al., 2006). Theoretically, the REACH trials are underpinned by the “stress-health” model and the REACH II interventions sought to employ interventions that would address the pathway of issues that comprise the proposed stress-health mechanism (see Figure 1).