In this multicenter, randomized controlled trial designed to target several problem areas, including CG self-care, the intervention package led to better self-rated health and subsequent reductions in CG burden and bother at 6-month follow-up. This relationship was mediated through decreases in CG depression levels. The finding that this intervention improved CG health in four domains of health (general self-rated health, sleep, mood improvement, and physical improvement) is a contribution to the caregiving literature because few studies have specifically examined CG health,15
with this trial being the only study to the authors' knowledge to specifically address the global concept area of CG health through a longitudinal intervention. One other study employing a health-related longitudinal intervention in dementia CGs (although targeting only one area of health: sleep)20
found that CGs' sleep quality improved as a result of the intervention, although there was no improvement in CGs' depression or burden levels.
In older adults in general, the presence of disease and disability negatively affects self-perceptions of health and emotional well-being.17
Also, previous studies have shown that having a positive view of one's health is highly associated with engaging in healthful behaviors, quicker recovery from illness, promotion of physical and emotional well-being, and greater longevity.17
Typically, CGs of persons with dementia have been found to report lower self-rated health scores, engage in fewer health-promoting behaviors, have worse illness-related symptoms and sleep problems, and have higher mortality than non-CG older adults.2,3,6–9,11,12,16
The stress of the caregiving role is often associated with this decline in CG health, such that, as perceived burden increases, CGs self-rated health declines, and the number of somatic symptoms increases.7,15,35
Previous cross-sectional studies have found that CGs who reported lower perceived burden with the caregiving role practiced more health-promoting behaviors than those reporting higher burden.36
This is similar to the results of the present study in that, upon follow-up, CGs who reported better health also reported lower perceived burden and bother with the caregiving role.
Although not a main focus of this study, racial and ethnic variations in the before and after measures of CG health, depression, burden and bother were examined. Hispanics and whites were more likely to report improvements in these domains than African Americans, although all racial and ethnic groups benefited from the intervention.21
Additionally, the results confirm that CGs from each ethnic or racial group who reported better health after receiving the intervention reported reductions in their burden and bother. That African Americans were the least likely to benefit from the intervention's effects is similar to a previous study in which researchers reported that none of the CG stressors measured (e.g., CRs' ADL and cognitive status, CGs' role strain) were significant predictors of CG psychosocial health at follow-up. Only CG comorbidity was reported to be a significant predictor of CG physical health at follow-up.18
The findings of the current study suggest that Hispanics were less likely to report role strain (total frustrations of caregiving, ADL, and IADL bother), whereas whites were more likely to report higher emotional burden with the caregiving role.
CGs have not uniformly been found to be more disadvantaged with regard to their health than non-CG older adults. A previous study found that, over a 3-year period, spouses of persons with dementia appeared to be healthier than comparison spouses, having fewer chronic conditions and lower comorbidity indices, even though their levels of health service utilization were equivalent to comparison spouses.5
This study may have obtained different results because spouses were not specifically identified as primary CGs. Two additional cross-sectional studies found that CGs did not report poorer health practices or engage in more health-risk behaviors than non-CGs and that CGs who reported higher levels of caregiving stress engaged in more self-care behaviors.6,37
The authors explained this finding by asserting that CGs performed more self-care behaviors when they were faced with greater illness symptoms. Although the present study did not specifically compare CGs with non-CGs, it remains pertinent that CGs in the intervention group were able to effect a change in their self-perceived health status that led to lower levels of depression and resultant decreases in burden and bother.
Additionally, previous studies examining CG health have found lower self-perceptions of health to be a powerful predictor of higher levels of depression.7,38
CGs' depressive symptoms have been found to have stronger associations with physical health than did objective stressors.16
Similarly, in the present study, depression was strongly correlated with each measure of CG health.
The relationship between the caregiving role and CG depression has been well documented, finding depression levels ranging from 28% to 55% for CGs of persons with dementia, compared with 15% in community surveys of older adults.7,8,10,39,40
There is a significant correlation between higher levels of CG depression and higher levels of burden and behavioral bother associated with the caregiving role, especially in spousal CGs.6–10
Although studies have shown that interventions targeting CG mental health (e.g., depression and anxiety) have been moderately successful in reducing the burden and behavioral bother CGs associate with their role,8,10,41,42
no previous interventional studies have targeted CGs' physical health and its relationship to caregiving outcomes. In the present study, depression was expected to have a role in any relationship physical health may have with caregiving outcomes; this hypothesis was tested through mediation analyses after finding correlations between physical health and caregiving outcomes. As expected, depression was a potent mediator of this relationship for all CG health and CG outcome variables. This is similar to the findings of a meta-analysis of caregiving studies (although not specific to dementia CGs), in which greater CG burden and more-severe depressive symptoms were related to worse physical health of CGs.16
Additionally, a cross-sectional investigation found that CGs who reported higher levels of caregiving stress had poorer self-rated health and physical functioning, larger number of illness symptoms, and higher levels of depressed mood; these variables also mediated the relationship between caregiving stress and self-care behaviors, with depression being a particularly potent mediator.6
The results of the present study suggest that this relationship also holds in the reverse, in that targeting improvement of CG health may result in lower levels of depression and CG burden and bother.
There are several limitations to the present study. It is possible that CGs' subjective health mediates the relationship between depression and CG outcomes, because previous research has shown subjective health to mediate the effects of disease and disability on depression in older adults,17
but CGs of persons with dementia are a specific subgroup of the older adult population in which previous research has demonstrated that declines in CG health have been shown to be correlated with increased levels of depression and that greater levels of depression are correlated with higher perceived CG burden and behavioral bother, making depression the most logical choice for the mediator in the relationships between CG health, burden, and bother.
Although it would be interesting to explore racial and ethnic variation in the strength of depression as a mediator for reported relations (e.g., between CG health and bother), this would entail six separate meditational analyses. However, conducting these analyses would increase experiment-wise Type 1 error markedly, thus invalidating the results.
Additionally, other factors not available in this secondary data analysis of REACH II might partially explain the relationships between CG self-reported health and burden and between CG self-reported health and bother. For example, investigators have found CG and CR depression to be highly correlated,43
although additional variables that were plausibly related to outcomes (e.g., CG comorbidity, CR physical functioning and problem behaviors) were explored, and none were found to be related to the outcomes in this study.
The CGs enrolled in the present study may also be a select subgroup of the older adult population, because previous researchers have posited that older adults taking on the caregiving role would need to be in a state of physical and mental health in which they were able to take on this role.7,11
This could mean that these CGs were in a superior state of physical and mental health when they assumed the caregiving role, although more than 40% of the CGs in the present study were spousal CGs who had been CGs for an average of 4.5 years, making their health status at the onset of caregiving less important to the present findings. Previous research has shown that, after several years of caregiving, informal CGs have more physical complaints than the general population according to age and sex15
and that spousal CGs rate health more poorly than adult children CGs.7
Thus, it is likely that the CGs in the present sample would no longer be in a better state of physical or mental health than when they began the CG role and than non-CGs.
The novelty of the present study is that it addresses the question of CG health in a longitudinal time-frame, showing that, when CGs receive knowledge and skills training in health and health behaviors, they are able to incorporate these practices into their daily routine. This not only improves their health, but also decreases their levels of depression and lessens the burden and bother they associate with the caregiving role. This study provides support for the assertion that negative health effects associated with the caregiving role can be ameliorated through this type of intervention. These findings suggest that clinicians should consider exploring CG risk factors (e.g., depression, burden, and bother) in practice and should target appropriate resources if these factors are present. A previous study recommended that clinicians use the Caregiver Assessment Tool developed by the American Medical Association to identify CGs at risk for adverse health outcomes.8
Because depression is one of several powerful contributors to CG burden, bother, and health outcomes, future research investigating CG health effects on CG outcomes should also examine other factors that have been found to mediate the relationship between CG stress and depression, including the quality of the CG–CR relationship, CG self-esteem, and social support.2