Introduction
Approximately, 47 million people worldwide were living with dementia in 2015, and the figure is likely to double in 20 years (Prince et al., Reference Prince, Ali, Guerche, Prina, Albanese and Wu2016). In this context, numerous studies have found a robust relationship between caring for patients with dementia (PWD) and negative health outcomes (Etters et al., Reference Etters, Goodall and Harrison2008). Caring for PWD involves important demands that may lead to exhaustion, frustration, and other adverse reactions among informal caregivers when the situation is maintained over time. In the case of caring for patients with Alzheimer's disease, the degree of dependence on the caregiver increases progressively and irreversibly, creating a perfect context for the occurrence of stress-related health problems. Not surprisingly, caring for a PWD has been considered even more stressful than caring for a person with a physical disability (Ory et al., Reference Ory, Hoffman, Yee, Tennstedt and Schulz1990).
It is well known that exposure to stress is associated with different health problems through the immune dysfunction (Glaser and Kiecolt-Glaser, Reference Glaser and Kiecolt-Glaser2005; Kemeny and Schedlowski, Reference Kemeny and Schedlowski2007), although coping strategies can help ameliorate the negative effect of stress on health and well-being (Raggi et al., Reference Raggi, Tasca, Panerai, Neri and Ferri2015; Snyder et al., Reference Snyder2015). In the context of caregiving, Pearlin et al.’s (Reference Pearlin, Mullan, Semple and Skaff1990) stress model underlines the importance of the subjective appraisal of resources to deal with the situation of caring, compared with the objective burden, such as degree of dependency or behavioral disturbances. Therefore, it seems that optimistic people use more problem-focused and adaptive coping strategies (Carver and Scheier, Reference Carver and Scheier2014). In this study, we adopted a perspective of optimism (also referred as “grounded” optimism) based on an integrated and multidimensional approach of generalized expectancies of control (GEC; Palenzuela et al., Reference Palenzuela, Prieto, Barros and Almeida1997; Palenzuela, Reference Palenzuela2008). From this point of view, optimism may be defined as the conviction of being able to exercise control (self-efficacy component) in an environment perceived as controllable (contingency component), which supports expectancies of goal achievement (success or outcome component). Previous research has found that a higher level of optimism in caregivers predicted less burnout (Contador et al., Reference Contador, Fernández-Calvo, Palenzuela, Miguéis and Ramos2012) and reduced demands of institutional care (Contador et al., Reference Contador2015). Despite these observations, the relationship between optimism and quality of life (QoL) among informal caregivers remains elusive.
QoL is defined as individuals’ perceptions of their position in life in the context of the culture and value systems in which they live, and in relation to their goals, expectancies, standards, and concerns (The WHOQOL Group, 2008). Previous studies have provided evidence supporting the case for control-related psychological resources and positive emotions (Roepke et al., Reference Roepke2008; Carver and Scheier, Reference Carver and Scheier2014) for the management of the adverse effects of caregivers’ role stress. Therefore, strategies to improve optimism or perception of control may improve the psychological adjustment. In this context, optimism may act as a mediator or moderator between known stress-related health risk factors and QoL (Márquez-González et al., Reference Márquez-González, Losada, Peñacoba and Romero-Moreno2009; Mausbach et al., Reference Mausbach2012). In fact, a protective relationship between optimism and all-cause mortality in old age has already been described (Giltay et al., Reference Giltay, Geleijnse, Zitman, Hoekstra and Schouten2004). However, as far as we know, the role of optimism as a psychological construct in QoL of informal caregivers of PWD remains unknown.
The objective of this study is to analyze the predictive value of optimism on perceived QoL among informal caregivers of PWD. To our knowledge, this is the first study attempting to evaluate this relationship considering the effect of different covariables, such as sociodemographic characteristics, patient's attributes, care situation, and burden. This research will potentially contribute to the development of interventions aimed at improving the well-being of caregivers of PWD.
Methods
Participants
A convenient sample of 130 informal caregivers (mean age = 58.62 ± 12.45; 36 males and 94 females) and their respective patients (mean age = 77.97 ± 6.02; 48 males and 82 females) was recruited through consecutive referrals to the local Association of Family Members of Patients with Alzheimer's (AFA) in Salamanca (semi-rural area, north western Spain). Informal caregivers who visited the AFA (from January to December 2009) because they were interested in specific adult day-care programs were invited to participate in the study. All caregivers volunteered to participate in the study. Their role was that of primary caregiver, taking on responsibility for any decisions and for the patient's well-being for at least 6 months. None of the caregivers were receiving specialized psychological support at the time of assessment, and they were living at home with the PWD. All care recipients met the DSM-IV-TR criteria for the diagnosis of dementia, which was corroborated by the general practitioner, and they were susceptible to receiving assistance in the AFA day-care center of Salamanca. A written informed consent was obtained from all the participants. This study was approved by the institutional review board of the AFA (Salamanca), conforming to the provisions of the Declaration of Helsinki.
Measures
Information obtained about PWD included age, gender, education, type of dementia, and time since diagnosis. All patients underwent a standard assessment protocol including the Clinical Dementia Rating (CDR) scale (Hughes et al., Reference Hughes, Berg, Danziger, Coben and Martin1982) to assess the severity of the syndrome. In addition, the Mini-Mental State Examination (MMSE) (Folstein et al., Reference Folstein, Folstein and McHugh1975), the Barthel index (Mahoney and Barthel, Reference Mahoney and Barthel1965), and the Neuropsychiatric Inventory-Brief Questionnaire Form (NPI-Q) (Kaufer et al., Reference Kaufer2000) were used to assess the patients’ cognitive status, functional impairment, and psychopathological symptoms, respectively.
All caregivers were also interviewed in one session divided into two parts: a sociodemographic questionnaire and a psychological protocol using instruments developed and/or validated into Spanish. The caregivers’ questionnaire provided sociodemographics (age, sex, and education) and data about context of care (relationship with the patients and duration of caregiving). In addition, the following standardized measures were included in this survey: the Zarit Burden Interview (Zarit et al., Reference Zarit, Todd and Zarit1986), the Goldberg Anxiety and Depression Scale (Goldberg et al., Reference Goldberg, Bridges, Duncan-Jones and Grayson1988), the Battery of Generalized Expectancies of Control Scales (BEEGC, acronym in Spanish; Palenzuela et al., Reference Palenzuela, Prieto, Barros and Almeida1997), and the World Health Organization Quality of Life-Brief (WHOQOL-BRIEF; The WHOQOL Group, 1998; Lucas-Carrasco, Reference Lucas-Carrasco2012).
Assessment of optimism and quality of life
The BEEGC is based on Palenzuela's approach to personal control (Palenzuela et al., Reference Palenzuela, Prieto, Barros and Almeida1997). The questionnaire includes 20 items distributed in five GEC-related scales (contingency, self-efficacy, success, helplessness, and luck). Respondents rate their degree of agreement with each statement on a nine-point Likert-type scale ranging from 1 (totally disagree) to 9 (totally agree). Independent scores are obtained by adding the items contained in each scale, which are positively formulated (e.g. high scores on each dimension represent higher levels of this construct). Although each dimension measures different theoretical concepts, we combined the scores to study the targeted psychological construct of optimism (self-efficacy, contingency, and success; range: 3–27), based on the confirmatory factor analysis of Palenzuela et al. (Reference Palenzuela, Prieto, Barros and Almeida1997). Therefore, the scales assess different theoretical constructs, but higher order constructs related to positive control expectancies (e.g. optimism) were obtained by calculating composite scores.
The WHOQOL-BRIEF version (The WHOQOL Group, 1998; Lucas-Carrasco, Reference Lucas-Carrasco2012) intended to produce a profile with four domain scores: physical health (seven items), psychological health (six items), social relationships (four items), and environment (eight items), plus two unscored questions about overall QoL and satisfaction with health. Participants rate how they felt in the domains over the last two weeks on a five-point scale. Domain scores are calculated by multiplying the mean of all the items included within the domain by four. Potential scores for each domain score, therefore, range from 4to 20. Higher scores indicate higher QoL.
Statistical analyses
Statistical analyses were performed using the Statistical Package for Social Sciences application, version 21.0 for Mac. Sociodemographic and clinical characteristics of groups were expressed as means (M) and standard deviation (SD). Caregivers with scores above the median (Mdn = 78) in the sum of the perceived personal control subscales (self-efficacy, contingency, and success) were categorized as optimistic caregivers (50.8% of the sample), whereas those with scores below the median value in perceived personal control (49.2% of the sample) were considered as non-optimistic. Pearson's correlation was used to analyze the association between quantitative variables. Analysis of variance (ANOVA) and Student's t-test (independent samples) were used to determine significant group differences for quantitative variables. Levene's tests were used to assess the homogeneity of variances for all variables. Only depression and burden scales did not satisfy with this assumption, so corrected p-values (equal variances not assumed) for t-contrast were considered for these factors. Moreover, Mann–Whitney U tests were also conducted to confirm the statistical significance of the parametric approach for these variables. Then, independent multiple regression models were conducted including optimism (main predictive variable) and QoL dimensions as the outcome variables. The inclusion of covariates (enter method) on each model was based on correlation analysis between the target variables and each QoL dimension. Therefore, the characteristics of attributes of caregivers and patients including optimism, age, education (years), and caring time (months), cognitive status (MMSE scores), functional impairment (the Barthel index), time from diagnosis (months), psychopathological symptoms (NPI-Q score), severity of dementia (CDR score), and burden were included as covariates. The significance adopted in the analysis was p < 0.05.
Results
Table 1 shows the characteristics of the sample as a function of caregivers’ level of optimism (optimistic vs. non-optimistic).
Characteristics of patients and caregivers as a function of caregivers’ level of optimism (n = 130)
a M/F = frequency for males/females.
b S = spouse; C = child; O = other.
c AD =Alzheimer-type dementia; OD = other dementias.
d Mild dementia = 1; moderate dementia = 2; severe dementia = 3.
* = < 0.01; ** = < 0.001
The groups of caregivers (optimistic vs. non-optimistic) did not differ in age, sex, or years of schooling. However, the percentage of caregivers who were first-degree relatives (spouses or children) was higher (92.03% vs. 69.69%) in the non-optimistic group than in the optimistic one. Second, there were no differences in the characteristics of patients cared for by optimistic versus non-optimistic caregivers, except for the type of dementia. In the optimistic group, 56.06% of the patients had Alzheimer's disease, whereas in the non-optimistic group, this percentage was only 25%. Finally, the optimistic group scored significantly higher than the non-optimistic group in physical, psychological, social, and environmental QoL, and lower in depression, anxiety, and burden. Statistical contrast for depression and burden remained significant using the Mann–Whitney test.
Association between optimism and QoL dimensions
Optimism scores positively correlated with all the QoL dimensions: physical health (r = 0.424, p < 0.001), psychological health (r = 0.554, p < 0.001), social relationships (r = 0.389, p < 0.001), and environment (r = 0.383, p < 0.001).
Patients’ and caregivers’ variables associated with QoL dimensions
Caregivers’ burden showed negative correlations with all the QoL dimensions: physical (r = −0.469, p = 0.001), psychological (r = −0.505, p < 0.001), social (r = −0.472, p < 0.001), and environmental (r = −0.494, p < 0.001). Caregiver's age (r = −0.191, p = 0.029) correlated with physical QoL negatively, whereas caring time showed a positive association with psychological QoL (r = 0.182, p = 0.038). Patients’ educational level was positively associated with caregivers’ social (r = 0.195, p = 0.026) and environmental QoL (r = 0.187, p = 0.033). Finally, greater dependence (r = 0.213, p = 0.015) and a longer period of time from diagnostic (r = −0.023, p = 0.023) were also associated with caregivers’ lower scores in environmental QoL.
Prediction of QoL dimensions
Table 2 includes multiple regression models using each dimension of QoL as outcome, and optimism as main predictor. Caregivers’ age, years of education, time of care, burden, and PWD's characteristics (independence, cognitive status, functional impairment, psychological and behavioral symptoms, time from diagnosis, and severity of dementia) were considered as covariates in all models. Optimism remained the best predictor of every dimension of QoL, even after controlling for the effect of all covariates.
Regression models for quality of life domains as outcome measures (n = 130)
Discussion
In this study, we showed that optimism is a significant predictor of QoL among informal caregivers, after controlling for the effect of different covariates. This prediction remained significant for all dimensions, even when burden was considered in all models. Therefore, optimism, defined by the combination of three GECs (contingency, self-efficacy, and success), is a relevant construct for predicting QoL dimensions among informal caregivers. This finding is consistent with previous studies that show the importance of psychological resources for caring of PWD (Márquez-González et al., Reference Márquez-González, Losada, Peñacoba and Romero-Moreno2009; Mausbach et al., Reference Mausbach2012; Carver and Scheier, Reference Carver and Scheier2014). Therefore, optimism may protect caregivers from the effects of anger on their physical health (López et al., Reference López, Romero-Moreno, Marquez-Gonzalez and Losada2013), burden (Contador et al., Reference Contador, Fernández-Calvo, Palenzuela, Miguéis and Ramos2012), or even suicide ideation (O'Dwyer et al., Reference O'Dwyer, Moyle, Zimmer-Gembeck and De Leo2013).
In this research, optimism predicted QoL in informal caregivers beyond burden and other clinical and sociodemographic variables, such as neuropsychiatric and behavioral symptoms or level of daily functioning, which traditionally have drawn more attention from researchers (Shin et al., Reference Shin, Carter, Masterman, Fairbanks and Cummings2005; Pinquart and Sörensen, Reference Pinquart and Sörensen2007). Optimistic expectancies, such as internal control, self-efficacy, and success, may encourage caregivers to engage in more effective coping skills. Thus, optimism may explain differences in the adaptation to this stressful situation by mitigating the negative consequences of caring for a PWD (Menezes de Lucena et al., Reference Menezes de Lucena, Fernández-Calvo, Hernández, Ramos and Contador-Castillo2006).
It seems that non-first-degree relatives were more prevalent in the optimistic group. Potentially, caring for PWD under this condition may be assumed more voluntary, whereas first-degree relatives experience more sense of responsibility or feel trapped by a family caregiving role (Pearlin et al., Reference Pearlin, Aneshensel and LeBlanc1997; Archbold, Reference Archbold1983). Moreover, the influence of sociocultural factors (e.g. cohabitation arrangements or rotation) should also be taken into account to explain this relationship (Rivera et al., Reference Rivera, Bermejo, Franco, Morales-González and Benito-León2009). Regarding differences in type of dementia, most optimistic caregivers deal with AD patients compared to less optimistic ones. More information and resources on AD, currently the most prevalent and researched type of dementia, are probably available compared to other dementias, which implies more control to deal with the caring situation (National Institute on Aging, 2018).
This study may contribute to understanding the positive role of optimism in QoL of informal caregivers, who have been reported to project part of their own QoL onto PWD (Arons et al., Reference Arons, Krabbe, Schölzel-Dorenbos, van der Wilt and Older Rikkert2013). This result supports the need to shift from a patient-focused approach to a combined patient- and caregiver-focused approach for interventions in dementia care. Interventions aiming to improve the QoL of informal caregivers of PWD should consider maximizing caregiver's psychological resources, such as optimism, fostering a subjective appraisal of control over one's life, especially in the presence of chronic conditions that involve dealing with stressors like fatigue or pain (Kurtz et al., Reference Kurtz, Kurtz, Given and Given2008). The ability of the informal caregiver to recognize the importance of caring for oneself is essential for themselves and quality of caring received by the PWD.
Our findings highlight the importance of optimism for QoL in family caregivers of PWD beyond subjective (burden) and objective stressors (behavioral disturbances). Hence, Pearlin et al. (Reference Pearlin, Mullan, Semple and Skaff1990) emphasized the effect of intrapsychic variables (e.g. sense of competence) as mediators on the relationship between the stressors (objective and subjective) and negative outcomes related to physical or psychological health of caregiving. Considering that optimism prevents subjective overload of family caregivers (Contador et al., Reference Contador, Fernández-Calvo, Palenzuela, Miguéis and Ramos2012), this research suggests that optimism has a moderator effect on the inverse relationship between burden and QoL of family caregivers. The small sample size and sociocultural differences should be considered as potential limitations before generalizing these findings to the whole caregivers’ population.
Finally, these results encourage the use of non-pharmacological interventions approaches based on GEC to improve the QoL of PWD caregivers. In fact, this research may help to understand the needs of informal caregivers and contribute to improve their QoL, supporting new intervention strategies based on GEC. Although prevention and reduction of burden is a key element of some interventions programs aimed to support family caregivers of PWD (Parker et al., Reference Parker, Mills and Abbey2008), the importance of GEC and related coping strategies to prevent the negative effect of stress on family caregivers has been ignored (Chien et al., Reference Chien2011). Therefore, interventions that foster optimism in caregivers of PWD would improve their QoL. Future research should further explore the relationship between optimism and health outcomes in order to optimize the care and management of PWD. Positive appraisals of the challenges of dementia-caregiving emerge as powerful psychological resources to enhance greater mental and physical health in informal caregivers.
Conflict of interest
None.
Description of authors’ roles
P. Ruisoto was responsible for the statistical design of the study, carrying out the statistical analysis, and writing the paper. I. Contador designed the study, collected the data, and wrote the paper. B. Fernández-Calvo formulated the research questions and designed the study. Finally, D. Palenzuela and F. Ramos supervised the data collection, statistical analysis, and writing the final draft of the manuscript.
Acknowledgments
The authors would like to thank the Velum Foundation and the Association of Family Members of Patients with Alzheimer's (AFA, Salamanca) for their collaboration in this study.
