Domains of quality of life in Alzheimer’s disease vary according to caregiver kinship

Abstract Introduction Compared to other types of caregiver, spouse-caregivers tend to be closer to people with Alzheimer’s disease (PwAD) because of their different position in the relationship. We designed this study to compare the differences in caregivers’ quality of life (QoL) and domains of QoL according to the kinship relationship between the members of caregiving dyads. Methods We assessed QoL of 98 PwAD and their family caregivers (spouse-caregivers, n = 49; adult children, n = 43; and others, n = 6). The PwAD and their caregivers completed questionnaires about their QoL, awareness of disease, cognition, severity of dementia, depression, and burden of caring. Results The comparison between caregiver types showed that spouse-caregivers were older, with higher levels of burden and lower scores for cognition. Caregivers’ total QoL scores were not significantly different according to type of kinship. However, there were significant differences in the domains physical health (p = 0.04, Cohen’s d [d] = -0.42), marriage (p = 0.01, d = 1.31), and friends (p = 0.04, d = -0.41), and life as a whole showed a trend to difference (p = 0.08, d = -0.33). When QoL domains were analyzed within dyads, there were significant differences between members of spouse dyads in the domains energy (p = 0.01, d = -0.49), ability to do things for fun (p = 0.01, d = -0.48), and memory (p = 0.000, d = -1.07). For non-spouse dyads, there were significant differences between caregivers and PwAD for the QoL domains memory (p = 0.004, d = -0.63), marriage (p = 0.001, d = -0.72), friends (p = 0.001, d = -0.65), and ability to do chores (p = 0.000, d = -0.76). Conclusions Differences were only detected between spouse/non-spouse-caregivers when QoL was analyzed by domains. We speculate that spouse and non-spouse caregivers have distinct assessments and perceptions of what is important to their QoL.


Introduction
Depression, anxiety and stress are common among the caregivers of people with Alzheimer's disease (AD).
Several studies have investigated how these factors affect caregivers' quality of life (QoL) and sense of burden, but these studies commonly include different types of caregivers, such as spouse, adult children, and other relatives who take care of people with Alzheimer's disease (PwAD). 1,2 Questions therefore remain in relation to whether there are differences in caregivers' perspectives on QoL according to the degree of kinship between caregiver and care receiver.
A meta-analysis comparing different types of caregivers showed that, because of their closer relationship with the PwAD, adult children caregivers report more depression and psychological distress related to caregiving when compared to children-in-law caregivers. 3 Moreover, caregivers who lived in the same home with the PwAD had lower QoL compared with those who did not. 4 In AD, when spouse-caregivers are compared to those with other types of kinship, they often feel more responsible for the caring activities and, consequently, present higher risk for feelings of burden and depression. 3 Spouse-caregivers perceived their role as being more stressful than non-spouse-caregivers, 5 and this may influence their evaluation of QoL. Although each member of the couple experiences different changes in the relationship, these data may be explained by hours of caring, change in intimacy, and generally older age. 3,6 Furthermore, the relationship may also be influenced by changes in sexual activity. Commonly, PwAD may not be able to remember what to do during sexual intercourse and/or exhibit inappropriate sexual behaviors, causing the spouse-caregiver to experience feelings of rejection. 7 Thus, the level of intimacy of the spouse-caregiver/PwAD couple may influence their QoL differently. If a spousecaregiver perceives the relationship as less distressing, the quality of care provided will be higher, resulting in higher QoL for the couple. 6 As a result, the quality of the marital relationship may be associated with QoL. 8 A perceived change in relationship was therefore found to be an important determinant of caregiver QoL. 4 Quality of life is a complex and multidimensional concept that comprises subjective and objective indicators, such as interpersonal relationships, family relationship, levels of chronic illness, housing, and changes to feelings. 6,9 In dementia, QoL includes four general domains: cognitive functioning, activities of daily living, social interaction, and psychological wellbeing. 9 According to Novelli et al., 10  1) to compare the influence of different kinships on caregivers' self-report QoL ratings; and 2) to compare the differences between PwAD self-report QoL domains and caregiver self-report QoL domains according to their degree of kinship. We hypothesized that QoL is lower in spouse-caregiver dyads than in non-spousecaregiver dyads and that overall PwAD self-report QoL scores are higher than caregivers self-report scores.

Participants
The sample comprised PwAD (n = 98; 43 males)  14 1 or 2 according to total score were included in the study.
In order to ensure that findings would be applicable to AD rather than other neurological problems, PwAD with history of head trauma, aphasia, alcoholism, psychiatric disorders, or epilepsy were excluded from the study. All PwAD were able to read and write simple sentences, interact with the interviewer, and understand and follow instructions.
Caregivers were classified into two categories: spouse-caregivers and non-spouse caregivers who were nonetheless the person primarily responsible for the's care. Only informal caregivers were included in the sample (i.e., family members or volunteers). Nonspouse caregivers who did not live with their charges should have been visiting them at least once to twice a week, in order to be able to comment on actual daily living behaviors and challenges. We excluded caregivers with a reported history of psychiatric or cognitive disorders. Only caregivers with MMSE scores of 28-30 were included in the study. All caregivers were able to provide detailed information about their charges. All caregivers had been previously informed of the diagnosis by the psychiatrist. Each member of the PwAD-caregiver pair was interviewed separately from the other member of the pair.

Caregivers' measurements
Quality of life. The same scale used to assess PwAD QoL was also administered to the caregivers (QoL C). 10 Cognition. This is the same scale (MMSE) used to assess PwAD cognition, but only caregivers who scored between 28 and 30 were included in the study sample. 13 Burden.

Description of the sample
The mean age of PwAD cared for by spouses was for non-spouse caregivers. The most prevalent type of non-spouse caregiver kinship was adult child (88%, n = 43). Sociodemographic data for dyads are shown in Table 1.  Caregivers. There were significant differences between spouse and non-spouse caregivers in cognition  Table 1.

Quality of life
Differences between self-report caregivers' QoL The differences in QoL domains and total score are shown in Tables 2 and 3.  We expected that spouse-caregivers would have lower QoL than non-spouse caregivers. The non-spouse caregivers did have a slightly higher QoL, although the difference in the QoL total score was not practical or statistically significant. Nonetheless, when QoL was analyzed by domains, non-spouse caregivers seemed to have more friends and perceived their own physical health as better than spouse-caregivers. Non-spouse caregivers commonly receive help from other family members, and provide less care than the spousecaregiver, who are often the primary caregiver. 3 In addition, it is possible that the fact that spousecaregivers were older may have influenced the way they perceived their physical health, since they are often frail themselves. 3 Studies have shown that better caregiver mental and physical health is consistently associated with better QoL. 4 This finding underlines the potential value of studying the differences between different caregiver groups in order to attend to their needs effectively.

PwAD and caregivers
Analysis of the total QoL scores showed that caregivers' self-report QoL was higher than PwAD's self-report QoL in both groups. Several studies have reported higher QoL scores for PwAD than for caregivers, because of the presence of impaired awareness of disease. 6,19,20 Conversely, we found that both groups of caregivers had better QoL than both groups of PwAD.
The most likely explanation may lie in the fact that our sample was recruited at a specialized outpatient clinic that offers many services for caregivers, such as psychoeducational groups and physician appointments, if necessary. According to Santos et al., 20  are asked to answer the same questions. In our sample, we found that spouse dyads differed in fewer QoL domains than non-spouse dyads. Discrepancies between the members of spouse dyads were only found in two domains (energy and ability to do things for fun), whereas non-spouse dyads had discrepancies in marriage, friends, and ability to do chores. Also, both groups had discrepancies for memory, as expected.
We may thus perceive that spouses become closer and develop mechanisms to cope with difficulties together, Second, although levels of burden were assessed, no analysis was conducted to investigate the influence of burden on caregivers' QoL. In our study, the majority of participants had mild disease and, maybe because of this, caregivers' burden was low. Commonly, caregivers with moderate levels of burden experience difficulties that negatively affect their QoL. 11 In future studies, we should include PwAD with more severe disease levels to further investigate the relationship between burden

Clinical implications and future directions
Quality of life is a multidimensional concept associated with expectations, concerns, and goals, including social, physical, and psychological functioning.
Because QoL is a complex concept, each group may evaluate it differently. The findings of this study help to decide whether promoting specific services can be recommended for each kind of kinship. Also, the study findings would allow providers and clinicians to promote good QoL both in PwAD and their caregivers, taking into consideration the characteristics and demands of each group.

Conclusion
The investigation of spouse and non-spouse caregivers' QoL did not detect a significant difference in QoL as a whole. On the other hand, when QoL was analyzed by domains, there were differences between spouse and non-spouse caregiver groups. Our findings show that different groups of caregivers have specific appraisals and perceptions regarding what is important to evaluate with regard to their own QoL. Even though the two groups did not differ significantly when QoL was evaluated as a single construct, each group considered different specific QoL-related domains to be important.
Quality of life is complex and should be evaluated in domains and not globally.