Despite the generally accepted belief that social support improves caregiver adjustment in general and subjective burden in particular, the literature shows mixed findings, and a recent review concluded that the predictive strength of caregiver social support in determining caregiver burden is less evident, due to the conceptual diversity of this determinant.
The purpose of this review is to analyse the relationship of perceived and received social support with subjective burden among informal caregivers of an adult or older adult.
A systematic search was carried out up to September 2017 in the following databases: MEDLINE (PubMed), CINAHL, EMBASE, PsycINFO), Scopus and ISI Proceedings, and a meta-analysis was performed with the results of the selected and included studies.
Fifty-six studies were included in the meta-analysis, which provided 46 independent comparisons for perceived support and 16 for received support. Most of these studies were cross-sectional. There was a moderate, negative association of perceived social support on subjective burden (r = -0.36; CI 95% = -0.40, -0.32) and a very small, negative association of received support on subjective burden (r = -0.05; CI 95% = -0.095, -0.001).
1) perceived and received support are not redundant constructs, 2) the relationships between social support and subjective burden depend on whether the social support is measured as perceived or received, 3) the relationship of perceived social support with subjective burden has a bigger effect size than that of received social support, the relation between received support and subjective burden being clinically irrelevant, 4) perceived social support may be a good predictor of subjective burden.
Implications of key findings
Our findings broadly support interventions promoting social support in caregivers to prevent or alleviate subjective burden, and specifically, to intervene on the promotion of perceived social support more than on the promotion of received social support when preventing or alleviating burden.
Citation: del-Pino-Casado R, Frías-Osuna A, Palomino-Moral PA, Ruzafa-Martínez M, Ramos-Morcillo AJ (2018) Social support and subjective burden in caregivers of adults and older adults: A meta-analysis. PLoS ONE 13(1): e0189874. https://doi.org/10.1371/journal.pone.0189874
Editor: Yinglin Xia, University of Illinois at Chicago College of Medicine, UNITED STATES
Received: June 19, 2017; Accepted: December 4, 2017; Published: January 2, 2018
Copyright: © 2018 del-Pino-Casado et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the paper and its Supporting Information files.
Funding: The authors received no specific funding for this work.
Competing interests: The authors have declared that no competing interests exist.
Social support can be defined as “the existence or availability of people on whom we can rely, people who let us know that they care about, value and love us” . Classically, this construct has been classified in two dimensions: structural and functional. The structural dimension refers to the size, composition and complexity of the social network [2,3]. The functional dimension comprises the functional types of assistance (given or available) which can usually be classified into: emotional, instrumental and informational . In addition, the functional dimension can be measured in two ways: perceived and received [5,6]. Perceived support refers to the assessment of the availability of support when it is needed, the appraisal of its adequacy and/or the quality of such support, whereas received support refers to the nature and frequency of specific support transactions [5,6].
Several researchers [7,8] have shown the positive effects of social support in psychological adjustment, health and well-being during the past three decades. However, despite these findings, limited progress has been made in understanding how social support works and in the specific mechanism linking social support and their benefits .
Social support and caregiving
Social support has been studied in several contexts, one of which is informal caregiving. The study of family caregiving is a good opportunity to analyse how social support is related to psychological outcomes . Caring for a relative is a stressful event that can have negative effects on caregivers’ health and well-being . In caregiving, social support has been analysed under the stress and coping models derived from the Transactional Stress Theory by Lazarus and Folkman . In these models, the consequences of the potential stressful events depend on the caregiver’s personal appraisal of these events and the caregiver’s resources such as social support. Based on these models, some authors have tried to theorize how social support modulates the stress consequences. In this sense, Cohen et al. [12,13] argued that social support may play a role at two different points in the causal sequence, linking stress to its consequences. First, the perception that others can provide necessary resources could lead to appraising a situation as less stressful. Second, the actual receipt of support may alleviate the impact of stress by providing a solution to the problem, by reducing the perceived importance of the problem, by providing distraction from the problem or by facilitating healthful behaviours. Thus, social support could diminish the impact of stressors on caregiver’s emotional situation [12,13].
Social support and subjective burden
Our study is focused on the relationship between social support and subjective caregiver burden. Subjective burden is a state characterized by fatigue, stress, perceived limited social contact and role adjustment, and perceived altered self-esteem. This state comes from a negative appraisal of the caregiving situation, and can threaten the physical, psychological, emotional and functional health of caregivers [14,15]. Subjective burden has been related to anxiety , depression [17,18], and negative effects on physical health . Thus, the analysis of how social support affects subjective burden could improve the health of the caregiver through early detection and early interventions on subjective burden.
Despite the generally accepted belief  that social support improves caregiver adjustment in general and subjective burden in particular, the literature shows mixed findings [9,20], existing works have linked social support to less subjective burden , more subjective burden  or shown no relationship . Moreover, a recent review about social functioning (including social support) and subjective burden in dementia caregivers  concluded that the predictive strength of caregiver social support in determining caregiver burden is less evident, due to the conceptual diversity of this determinant.
Researchers have tried to explain previous heterogeneity and scarcity of evidence by analysing perceived and received social support separately, based on the hypothesis that perceived support has more consistently related to beneficial health outcomes than received social support . However, results in the last review about the relationships between social support and psychological adjustment in caregivers (including subjective burden)  were not conclusive because of the heterogeneity of its findings, the few studies included and the absence of meta-analytic assessment.
The purpose of this review is to analyse the effects of perceived and received social support on subjective burden among informal caregivers of an adult or older adult.
To achieve the above objectives, we conducted a quantitative systematic review with meta-analysis. For the review, we followed the methodology proposed by Roe  and the reporting standards of the PRISMA Statement , where appropriate.
Electronic databases (MEDLINE—PubMed-, CINAHL—EBSCO-, EMBASE—Elsevier-, PsycINFO—ProQuest-, Scopus—Elsevier- and ISI Proceedings) were searched without time or language limits. The searching terms used across previous databases were social support, informal support, social network, perceived support, received support, burden, strain, role overload, caregiver and career. The searches ranged from the first year included in each database until September 2017. We also conducted manual searches of relevant scientific journals (nursing, psychological and medical) and reference lists in selected papers and previous reviews [3,9] for the period between January 1990 and September 2017.
Inclusion criteria used for selecting papers were: (a) original, quantitative studies (b) about informal caregivers of adult or older adult care-recipients (18 years old or more), (c) that related caregiver subjective burden and social support (d) yielding a correlation coefficient or another measure that could be transformed into a correlation coefficient.
To increase the validity of these eligibility criteria, the following considerations were taken into account: 1) we considered “informal caregivers” as unpaid caregivers (family members, friends, community members or volunteers) who care both in institutions and at home , and “adult or older adult care-recipients” as persons 18 years old or more who are dependent in at least one activity of daily living or instrumental activity of daily living; 2) caregiver subjective burden had to be measured as one-dimensional; 3) social support had to be classifiable into perceived or received social support. We consider received support when frequency of support were measured and perceived support when satisfaction (or adequacy) or availability were measured . In this sense, tools that included without any differentiation both perceived and received social support (e.g. the Arizona Social Support Interview Schedule ) and perceived or received social support together with the social network size (e.g. the Lubben Social Network Scale ) were rejected. We only selected studies in which social support was measured with tools that included all types of functional dimensions (instrumental, informational and emotional), rejecting studies that included measures of specific functional dimensions.
Social support in selected papers was classified by two reviewers (RdPC and AFO) (agreement in 87% of the studies), using the definitions shown above [5,6]. We resolved any disagreement through discussion or, if required, we consulted a third review author (AJRM).
Data extraction and synthesis
Two independent reviewers (RdPC and PAPM) extracted the population characteristics, the type of social support (perceived or received social support), and the effect estimates of each study using a standardized data extraction form. In case of disagreement, both reviewers examined the documents together following the decision rule identified in the data extraction protocol until consensus was reached.
The effect measure used to compute the combined effect was the correlation coefficient adjusted by the inverse of the variance using a random effects model. According to Cohen , values for effect size of 0.1–0.29, 0.3–0.49 and higher than 0.5 correspond to a small, moderate and large effect size, respectively. In repeated measured studies with no relation between time points, the first measure was chosen. When a study measured social support and subjective burden but did not relate them, correlation values were requested from the authors. Among the authors approached, two of them [32, 33] sent the solicited data.
Basing on the recommendations of Boyle  and Viswanathan et al., we used the following criteria for assessing the methodological quality of the individual studies: (1) sampling: probabilistic sampling, (2) measures: presence of information about the measurement process, content validity and internal consistency in the target population or a similar population, and absence of information bias (3) control for confounding factors: at least one measure of objective burden must be controlled for, and (4) adequate statistical analysis.
Regarding the control of confounders, we decided to control objective burden because this construct is the most intimately related with subjective burden . Objective burden comprises functional capacity, cognitive impairment and behavioural problems . Because previous measures are highly correlated , we decide to control at least one of them. We consider that confounders are controlled when the allocation between the groups or match groups is adequate (e.g., through stratification, matching, propensity scores) or confounders are taken into account in the design and/or analysis (e.g., through matching, stratification, interaction terms, multivariate analysis, or other statistical adjustment such as instrumental variables) . In case of statistical adjustment, we consider that there is no confounding bias when the variation of the point estimate is less than 10% .
To meet criteria, criteria 2 and 4 were considered as mandatory. Two independent reviewers (RdPC and MRM) assessed the included studies. Any disagreement was resolved by discussion or by involving a third assessor (AJRM). We chose objective primary stressors because the caregiving literature shows that these factors are the main determinants of subjective burden .
Following the recommendations of Meader et al. , based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system , imprecision, inconsistency and risk of publication bias of the results of the meta-analysis were assessed. Imprecision was evaluated by the number of included studies (large: >10 studies, moderate: 5–10 studies and small: <5 studies) and the median sample size (high: >300 participants, intermediate: 100–300 participants and low: <100 participants). Inconsistency was measured through heterogeneity of findings in individual studies. Publication bias was evaluated by analysing the funnel plot and by the statistical tests explained in the Analysis section.
All reviewers participating in selection, extraction and quality evaluation of the studies were bilingual.
Following the recommendations of Cooper et al. , a random effects model was used for the meta-analysis in order to improve the generalization of the findings to any caregiver of an adult or older adult care-recipient.
The Q test was used for the analysis of heterogeneity, together with the degree of inconsistency (I2) of Higgins et al. . Following the recommendations of Guyatt et al. , we used several methods for evaluating publication bias in order to strengthen the findings. These methods were evaluation of the funnel plot, the Begg’s test , the Egger’s test  and the Trim and Fill method . The Begg’s test and the Egger’s test evaluate the asymmetry of the funnel plot. In these tests, a p value less than 0.10 suggests publication bias, that is, the publication or non-publication of research findings, depending on the nature and direction of the results . The Trim and Fill method computes the combined effect considering a possible publication bias .
Sensitivity analyses were carried out to investigate the robustness of the findings. We used the leave-one-out method and subgroup analyses. The leave-one-out method consists of, given k studies, performing k-1 meta-analyses removing one study and analysing the remaining k-1 studies each time. The subgroup analyses were conducted to analyse differences between subgroups based on quality criteria or type of perceived support.
Analyses were performed using the Comprehensive Meta-Analysis 3.3 software.
A total of 5,710 records were retrieved from the databases searched. In addition, nine references were achieved from searching the references of included articles (Fig 1). After removing duplicates, 3,638 records were screened, of which 3,279 were excluded as not being relevant. Thus, 359 documents were assessed for eligibility, of which 153 were excluded by being not relevant and 137 by not meeting the eligibility criteria. Finally, 69 documents were selected for quality assessment, of which 56 met the quality criteria 2 and 4, and were finally included in the review (40 with perceived social support [32, 33, 46–83], 13 with received social support [21, 23, 84–94] and 3 with both measures [95–97]). We analysed each type of support separately. A summary of the results is shown in Table 1.
Perceived social support
Forty-three studies [32, 33, 46–83, 95–97] relating perceived social support and subjective burden were included in this review (Table 2). These studies contained 46 independent samples with 46 independent comparisons. Most of these studies had non-probabilistic samples (n = 41) and had no control for confounders (n = 29). The main care recipients were persons with dementia (n = 11) and frail older adults (n = 10). Regarding design, 41 were cross-sectional, one was repeated measured study with cross-sectional measures in each time point and one was case-control. Regarding the type of perceived social support, 24 studies measured satisfaction with support and 19 availability of support.
The combined effect (r = -0.36; 95% CI = -0.40, -0.32; N = 6,246; median sample size: 135.8) showed a moderate, negative effect (Table 1). Thus, caregivers with high perceived support experience less subjective burden. The effects in the individual samples were negative (except in one) and statistically significant (except in six studies) (Fig 2). The leave-one-out method yielded variations in the combined estimate under 2.2% (from -0.353 to -0.368). We consider the result of the meta-analysis as precise because of the width of the confidence intervals, the numbers of studies included and the median sample size. A very low heterogeneity was found among the results of these individual studies (Q = 45.8, degree of freedom [df] = 45, p> 0.10, I2 = 1.7%).
Regarding publication bias, the funnel plot (Fig 3) seems somewhat symmetric. The small studies did not show any tendency regarding their effect sizes and these studies had no bigger effect sizes than larger studies. The Egger’s test (p = 0.88) and the Begg’s test (p = 0.99) excluded the publication bias. In addition, the combined effect calculated by the Trim and Fill method (r = -0.39) varied by 8.3%.
No differences were found between studies controlling objective primary stressors (r = -0.37; 95% CI = -0.42, -0.32; 14 samples) and those not controlling it (r = -0.36; 95% CI = -0.41, -0.31; 32 samples).
Regarding the type of perceived social support, no differences were found between studies measuring satisfaction with social support (r = -0.39; 95% CI = -0.43, -0.35; 25 samples) and those measuring availability of social support (r = -0.33; 95% CI = -0.40, -0.26; 21 samples).
Received social support
Sixteen studies [21, 23, 84–97] relating received social support and subjective burden were incorporated in the present review (Table 3). These studies included 16 independent samples with 16 independent comparisons. These studies were cross-sectional (n = 14) or repeated measured studies with cross-sectional measures in each time point. All the studies had non-probabilistic samples and most of these studies (n = 12) had no control for confounders. The main care recipients were frail older adults (n = 5).
The combined effect (r = -0.05; 95% CI = -0.095, -0.001; N = 7,227; median sample size: 451.7) showed a very small, negative effect (Table 1). Thus, caregivers with high received support experience less subjective burden but the effect size of this relationship is very small. The effects in the individual studies were negative in 9 cases and positive in 7, and statistically significant in 5 cases (Fig 4). The leave-one-out method yielded variations in the combined estimate from 15.5% (r = 0.038) to 28.8% (r = 0.058), and the result of the meta-analyses turned out to be non-statistically significant in 10 cases. We consider the result of the meta-analysis as precise because of the width of the confidence intervals, the numbers of studies included and the median sample size. A low to moderate heterogeneity was found among the results of the individual studies (Q = 18.78, df = 15, p> 0.10, I2 = 20.14%).
Concerning publication bias, the funnel plot (Fig 5) seems somewhat symmetric. The small studies did not show any tendency regarding their effect sizes and these studies had no bigger effect sizes than larger studies. The Egger’s test (p = 0.80) and the Begg’s test (p = 0.13) excluded publication bias. Furthermore, the combined effect calculated by the Trim and Fill method (r = -0.05) did not vary.
No differences were founds between studies controlling objective primary stressors (r = -0.07; 95% CI = -0.16, 0.01; three studies) and those not controlling it (r = -0.04; 95% CI = -0.09, 0.02; 13 studies).
In the present review, subjective burden has been negatively related to perceived social support (with a moderate effect size) and received social support (with a very low effect size), in caregivers of an adult or older adult care-recipient.
The findings of the meta-analyses performed were reasonably accurate, valid and robust, based on the high number of included studies, the low level of heterogeneity of the results in individual studies, the low risk of publication bias, and the sensitivity analysis. Regarding the methodological quality of the included studies, there is a low risk of classification bias and errors in analysis in these studies, but most of the included studies had non-probabilistic samples and did not control for confounders. One of the main problems in systematic reviews of observational studies is the control of confounders . In this review, we included strategies for evaluating this issue and demonstrated that the control of objective burden in individual studies did not affect the results of the present meta-analysis. On the other hand, all the studies included in this review, except one, were cross-sectional or repeated measures studies that did not relate to the different time points. So, no causal relationship can be extracted from the present review. However, the findings in the present study are consistent with a caregiving theoretical framework in which social support is related to subjective burden , although no causation sequence can be established.
The present review showed that the relationships between social support and subjective burden depend on whether the social support is measured as perceived or received. This issue can explain the mixed results commented upon in the background section [9,20]. Our findings contribute to explain these mixed results, demonstrating that the relationships between social support and subjective burden can vary according the type of support measured.
The different relationship between received and perceived support with subjective burden could be due to variations of measures of social support, context, type of caregivers, or confounders. Because we only selected studies in which social support included all types of functional dimensions, it is unlikely that variations between perceived and received support regarding subjective burden are due to variations in the type of functional dimension. The low heterogeneity found in the meta-analyses support previous idea and underline that the above-mentioned differences between received and perceived support are not due to context or type of caregivers. Last, because we have demonstrated that studies with adequate control of confounders are similar results to those that do not.
In this review, perceived social support is more consistently related to subjective burden than received social support. In addition, the relationship of perceived social support with subjective burden has a bigger effect size than that of received social support. These findings are consistent with those of studies in other populations [25,98], in which perceived support is more strongly related with health indicators than received support. Our findings support the consideration of perceived social support as a possible good predictor of subjective burden in caregivers of adult or older adult care-recipients.
Since subjective burden is the consequence of the evaluation of stressors in the caregiving situation , the negative relationship between this construct and perceived social support could prove that the perception of the social support as adequate is related to appraising a situation as less stressful, according with the approach of Cohen et al. [12,13]. However, our findings do not discard the inverse hypothesis (subjective burden can lead to a worse evaluation of social support) or the reciprocal influence.
Regarding received social support and subjective burden, our findings extend the current knowledge showing the relationship between them as clinically irrelevant in caregivers. Therefore, the theoretically argued [12,13] stress-buffer effect of received social support is scarce. This clinical irrelevance could be explained by the findings of Melrose et al. , which showed that received support is related to emotional health when the need for support was considered, that is, when received support was measured as the number of times support was received when needed. In contrast, received support is not related to emotional health when it was measured as the number of times support was received .
Thus, our findings extend the evidence that perceived and received support are not redundant constructs. Therefore, models, research and clinical questions must take into account their separable and joint influence.
Several studies have analysed the efficacy of social support interventions in caregivers, yielding heterogeneous outcomes . When intervening on social support, two targets are possible : 1) closer family members, increased frequency of seeing others and/or more emotional support (promoting perceived social support through increasing “feeling connected”) and 2) validation and building of new friendships (promoting received social support through “building connections”). Our findings broadly support interventions to promote social support in caregivers to prevent or alleviate subjective burden, and specifically, to intervene on “feeling connected” more than on “building connections” when preventing or alleviating burden.
Therefore, our findings support the use of perceived rather than received social support when preventing or alleviating subjective burden, because perceived support may be better predictor of subjective burden than received support and interventions to promote perceived support to reduce subjective burden may be more appropriate than those promoting received support.
As we discussed above, our study had the limitation that all the studies included in this review, except one, were cross-sectional or repeated measures studies that did not relate to the different time points (no causal relationship can be extracted).
Several conclusions can be extracted from this study, regarding caregivers of adult and older adult care-recipients: 1) perceived and received support are not redundant constructs, 2) the relationships between social support and subjective burden depend on whether the social support is measured as perceived or received, 3) the relationship of perceived social support with subjective burden has a bigger effect size than that of received social support, the relation between received support and subjective burden being clinically irrelevant, 4) perceived social support may be a good predictor of subjective burden, 5) the perception of social support as adequate may be related to appraising a situation as less stressful, 6) Our findings broadly support interventions to promote social support in caregivers to prevent or alleviate subjective burden, and specifically, to intervene on the promotion of perceived social support more than on the promotion of received social support when preventing or alleviating burden.
For future research, more longitudinal studies are needed to enhance the causal relationships between social support and subjective burden.
- 1. Sarason IG, Levine HM, Basham RB, Sarason BR (1983) Assessing social support: The social support questionnaire. Journal of personality and Social Psychology 44: 127.
- 2. Thompson EH, Futterman AM, Gallagher-Thompson D, Rose JM, Lovett SB (1993) Social support and caregiving burden in family caregivers of frail elders. J Gerontol 48: 245–254.
- 3. Vrabec NJ (1997) Literature review of social support and caregiver burden, 1980 to 1995. Journal of Nursing Scholarship 29: 383–388.
- 4. Chang BL, Brecht M-L, Carter PA (2001) Predictors of social support and caregiver outcomes. Women & Health 33: 39–61. pmid:11523640
- 5. Gottlieb BH, Bergen AE (2010) Social support concepts and measures. J Psychosom Res 69: 511–520. pmid:20955871
- 6. Uchino BN, Bowen K, Carlisle M, Birmingham W (2012) Psychological pathways linking social support to health outcomes: a visit with the "ghosts" of research past, present, and future. Soc Sci Med 74: 949–957. pmid:22326104
- 7. Wang HH, Wu SZ, Liu YY (2003) Association between social support and health outcomes: a meta-analysis. Kaohsiung J Med Sci 19: 345–351. pmid:12926520
- 8. Holt-Lunstad J, Smith TB, Layton JB (2010) Social relationships and mortality risk: a meta-analytic review. PLoS Med 7: e1000316. pmid:20668659
- 9. Smerglia VL, Miller NB, Sotnak DL, Geiss CA (2007) Social support and adjustment to caring for elder family members: A multi-study analysis. Aging and Mental Health 11: 205–217. pmid:17453554
- 10. Pinquart M, Sorensen S (2003) Differences between caregivers and noncaregivers in psychological health and physical health: A meta-analysis. Psychology and Aging 18: 250–267. pmid:12825775
- 11. Lazarus RS, Folkman S (1984) Stress, appraisal and coping. New York, NY: Springer.
- 12. Cohen S, Wills TA (1985) Stress, social support, and the buffering hypothesis. Psychological bulletin 98: 310–357. pmid:3901065
- 13. Cohen S, Gottlieb BH, Underwood LG (2000) Social relationships and health. In: Cohen S, Underwood LG, Gottlieb BH, editors. Social support measurement and intervention: A guide for health and social scientists. New York, NY: Oxford University Press. pp. 3–25.
- 14. Zarit SH, Reever KE, Bach-Peterson J (1980) Relatives of the impaired elderly: Correlates of feelings of burden. Gerontologist 20: 649–654. pmid:7203086
- 15. Kim H, Chang M, Rose K, Kim S (2012) Predictors of caregiver burden in caregivers of individuals with dementia. J Adv Nurs 68: 846–855. pmid:21793872
- 16. Cooper C, Balamurali TB, Livingston G (2007) A systematic review of the prevalence and covariates of anxiety in caregivers of people with dementia. International Psychogeriatrics 19: 175–195. pmid:17005068
- 17. Schoenmakers B, Buntinx F, Delepeleire J (2010) Factors determining the impact of care-giving on caregivers of elderly patients with dementia. A systematic literature review. Maturitas 66: 191–200. pmid:20307942
- 18. Pinquart M, Sorensen S (2003) Associations of stressors and uplifts of caregiving with caregiver burden and depressive mood: a meta-analysis. Journals of Gerontology Series B: Psychological Sciences and Social Sciences 58: P112–128.
- 19. Carretero S, Garces J, Rodenas F, Sanjose V (2009) The informal caregiver’s burden of dependent people: Theory and empirical review. Archives of Gerontology and Geriatrics 49: 74–79. pmid:18597866
- 20. Wittenberg-Lyles E, Washington K, Demiris G, Oliver DP, Shaunfield S (2014) Understanding social support burden among family caregivers. Health Commun 29: 901–910. pmid:24345081
- 21. Verbakel E, Metzelthin SF, Kempen GI (2016) Caregiving to Older Adults: Determinants of Informal Caregivers’ Subjective Well-being and Formal and Informal Support as Alleviating Conditions.
- 22. Lechner VM (1993) Support systems and stress reduction among workers caring for dependent parents. Soc Work 38: 461–469. pmid:8362279
- 23. Kruithof WJ, Post MW, van Mierlo ML, van den Bos GA, de Man-van Ginkel JM, Visser-Meily JM (2016) Caregiver burden and emotional problems in partners of stroke patients at two months and one year post-stroke: Determinants and prediction. Patient education and counseling 99: 1632–1640. pmid:27103190
- 24. van der Lee J, Bakker TJ, Duivenvoorden HJ, Droes RM (2014) Multivariate models of subjective caregiver burden in dementia; a systematic review. Ageing Res Rev. pmid:24675045
- 25. Melrose KL, Brown GDA, Wood AM (2015) When is received social support related to perceived support and well-being? When it is needed. Personality and Individual Differences 77: 97–105.
- 26. Roe B (2007) Key stages and considerations when undertaking a systematic review: bladder training for the management of urinary incontinence. In: Webb C, Roe B, editors. Reviewing research evidence for nursing practice: systematic reviews. Oxford: Blackwell. pp. 9–22.
- 27. Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009) The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. J Clin Epidemiol 62: 1006–1012.
- 28. Del-Pino-Casado R, Frias-Osuna A, Palomino-Moral PA, Pancorbo-Hidalgo PL (2011) Coping and subjective burden in caregivers of older relatives: a quantitative systematic review. Journal of Advanced Nursing 67: 2311–2322. pmid:21658096
- 29. Barrera M (1983) A method for the assessment of social support networks in community survey research. Connections 3: 8–13.
- 30. Lubben J, Blozik E, Gillmann G, Iliffe S, von Renteln Kruse W, Beck JC, et al. (2006) Performance of an abbreviated version of the Lubben Social Network Scale among three European community-dwelling older adult populations. Gerontologist 46: 503–513. pmid:16921004
- 31. Cohen J (1992) A power primer. Psychological Bulletin: 155–159. pmid:19565683
- 32. Davis LC, Sander AM, Struchen MA, Sherer M, Nakase-Richardson R, Malec JF (2009) Medical and psychosocial predictors of caregiver distress and perceived burden following traumatic brain injury. Journal of Head Trauma Rehabilitation 24: 145–154. pmid:19461362
- 33. Goldsworthy B, Knowles S (2008) Caregiving for Parkinson’s disease patients: an exploration of a stress-appraisal model for quality of life and burden. J Gerontol B Psychol Sci Soc Sci 63: P372–376. pmid:19092040
- 34. Boyle MH (1998) Guidelines for evaluating prevalence studies. Evidence Based Mental Health 1: 37–39.
- 35. Viswanathan M, Berkman ND, Dryden DM, Hartling L (2013) Assessing risk of bias and confounding in observational studies of interventions or exposures: further development of the RTI Item Bank. Rockville, MD: Agency for Healthcare Rsearch and Quality.
- 36. Aneshensel CS, Pearlin LI, Mullan JT, Zarit SH, Whitlatch CJ (1995) The organization of stressors in the lives of caregivers. In: Aneshensel CS, Pearlin LI, Mullan JT, Zarit SH, Whitlatch CJ, editors. Profiles in Caregiving. San Diego, CA: Academic Press.
- 37. Rothman KJ, Greenland S, Lash TL (2008) Modern epidemiology: Lippincott Williams & Wilkins.
- 38. Meader N, King K, Llewellyn A, Norman G, Brown J, Rodgers M, et al. (2014) A checklist designed to aid consistency and reproducibility of GRADE assessments: development and pilot validation. Syst Rev 3: 82. pmid:25056145
- 39. Atkins D, Best D, Briss PA, Eccles M, Falck-Ytter Y, Flottorp S, et al. (2004) Grading quality of evidence and strength of recommendations. BMJ 328: 1490–1494. pmid:15205295
- 40. Cooper HM, Hedges LV, Valentine JC (2009) The handbook of research synthesis and meta-analysis. New York, NY: Russell Sage Foundation Publications.
- 41. Higgins J, Thompson S, Deeks J, Altman D (2002) Statistical heterogeneity in systematic reviews of clinical trials: a critical appraisal of guidelines and practice. Journal of health services research & policy 7: 51–61.
- 42. Guyatt GH, Oxman AD, Montori V, Vist G, Kunz R, Brozek J, et al. (2011) GRADE guidelines: 5. Rating the quality of evidence—publication bias. J Clin Epidemiol 64: 1277–1282. pmid:21802904
- 43. Begg CB, Mazumdar M (1994) Operating characteristics of a rank correlation test for publication bias. Biometrics 50: 1088–1101. pmid:7786990
- 44. Egger M, Davey Smith G, Schneider M, Minder C (1997) Bias in meta-analysis detected by a simple, graphical test. British Medical Journal 315: 629–634. pmid:9310563
- 45. Duval S, Tweedie R (2000) Trim and Fill: A Simple Funnel Plot-Based Method of Testing and Adjusting for Publication Bias in Meta-Analysis. Biometrics 56: 455–463. pmid:10877304
- 46. Alvarez-Ude F, Valdes C, Estebanez C, Rebollo P (2004) Health-related quality of life of family caregivers of dialysis patients. J Nephrol 17: 841–850. pmid:15593060
- 47. Annisa F (2015) Predicting Factors of Burden among Family Caregivers of Patients with Schizophrenia in Surabaya, Indonesia. Thai Pharmaceutical and Health Science Journal 10: 87–97.
- 48. Artaso B, Goñi A, Biurrun A (2003) Cuidados informales en la demencia: predicción de sobrecarga en cuidadoras familiares [Informal care in dementia: prediction of burden in caregivers]. Rev Esp Geriatr Gerontol 38: 212–218.
- 49. Bainbridge D, Krueger P, Lohfeld L, Brazil K (2009) Stress processes in caring for an end-of-life family member: application of a theoretical model. Aging Ment Health 13: 537–545. pmid:19629778
- 50. Blake H, Lincoln NB (2000) Factors associated with strain in co-resident spouses of patients following stroke. Clin Rehabil 14: 307–314. pmid:10868726
- 51. Cassidy T (2013) Benefit finding through caring: The cancer caregiver experience. Psychology & Health 28: 250–266. pmid:22928621
- 52. Chiou CJ, Chang HY, Chen IP, Wang HH (2009) Social support and caregiving circumstances as predictors of caregiver burden in Taiwan. Archives of Gerontology and Geriatrics 48: 419–424. pmid:18602706
- 53. Clair JM, Fitzpatrick KM, La Gory ME (1995) The impact of psychosocial resources on caregiver burden and depression: Sociological variations in a gerontological theme. Sociological Perspectives 38: 195–215.
- 54. Del-Pino-Casado R, Millan-Cobo MD, Palomino-Moral PA, Frias-Osuna A (2014) Cultural Correlates of Burden in Primary Caregivers of Older Relatives: A Cross-sectional Study. Journal of Nursing Scholarship 46: 176–186. pmid:24588946
- 55. Edwards NE, Scheetz PS (2002) Predictors of burden for caregivers of patients with Parkinson’s disease. J Neurosci Nurs 34: 184–190. pmid:12197259
- 56. Gallart A (2013) Factors influencing burden among non-professional immigrant caregivers: a case–control study. Journal of Advanced Nursing 69: 642–654. pmid:22670884
- 57. Goris S, Klc Z, Elmal F, Tutar N, Takc O (2016) Care Burden and Social Support Levels of Caregivers of Patients with Chronic Obstructive Pulmonary Disease. Holist Nurs Pract 30: 227–235. pmid:27309411
- 58. Greenberger H, Litwin H (2003) Can burdened caregivers be effective facilitators of elder care-recipient health care? J Adv Nurs 41: 332–341. pmid:12581098
- 59. Hanks RA, Rapport LJ, Vangel S (2007) Caregiving appraisal after traumatic brain injury: The effects of functional status, coping style, social support and family functioning. NeuroRehabilitation 22: 43–52. pmid:17379947
- 60. Kahriman F, Zaybak A (2015) Caregiver Burden and Perceived Social Support among Caregivers of Patients with Cancer. Asian Pac J Cancer Prev 16: 3313–3317. pmid:25921137
- 61. Kaur N (2014) Caregiving, Burden and Social support among caregivers of Schizophrenic patients. Delhi Psychiatric Journal 17: 337–342.
- 62. Leibach G (2013) Examining the Relations Between the Mental Health and Physical Health of Caregivers of MS in a Mexican Sample.
- 63. Liu Y, Insel KC, Reed PG, Crist JD (2012) Family caregiving of older Chinese people with dementia: testing a model. Nurs Res 61: 39–50. pmid:22166908
- 64. López Alonso SR, Moral Serrano MS (2005) Validación del Índice de Esfuerzo del Cuidador en la población española [Validation of the Caregiver Strain Index in a Spanish population]. Enfermería Comunitaria 1: 12–17.
- 65. Losada A, Perez-Penaranda A, Rodriguez-Sanchez E, Gomez-Marcos MA, Ballesteros-Rios C, Ramos-Carrera IR, et al. (2010) Leisure and distress in caregivers for elderly patients. Archives of Gerontology and Geriatrics 50: 347–350. pmid:19573933
- 66. Majerovitz SD (2007) Predictors of burden and depression among nursing home family caregivers. Aging Ment Health 11: 323–329. pmid:17558583
- 67. Manso Martínez ME, Sáchez Lóez MdP, Flores IC (2013) Salud y sobrecarga percibida en personas cuidadoras familiares de una zona rural [Health and perceived overload in people involved in family care in a rural area]. Clínica y Salud 24: 37–45.
- 68. Marwit SJ, Meuser TM (2002) Development and initial validation of an inventory to assess grief in caregivers of persons with Alzheimer’s disease. Gerontologist 42: 751–765. pmid:12451156
- 69. Molina Linde JM, Iáñez Velasco MA, Iáñez Velasco B (2005) El apoyo social como modulador de la carga del cuidador de enfermos de Alzheimer [El apoyo social como modulador de la carga del cuidador de enfermos de Alzheimer]. Psicología y Salud 15: 33–43.
- 70. Moller-Leimkuhler AM, Wiesheu A (2012) Caregiver burden in chronic mental illness: the role of patient and caregiver characteristics. Eur Arch Psychiatry Clin Neurosci 262: 157–166. pmid:21538092
- 71. Moral MS, Juan J, López MJ, Pellicer P (2003) Perfil de riesgo de morbilidad psíquica en cuidadores de pacientes ingresados en su domicilio [Profile and risk of mental illness in caregivers for home care patients]. Aten Primaria 32: 77–87.
- 72. Muñoz Bermejo L, Postigo Mota S, Casado Verdejo I, Llanos Peña Fd (2015) El cuidador mayor de personas mayores. Sobrecarga y apoyo social [The elderly caregiver of older people]. Revista Rol de Enfermería 38: 852–858.
- 73. Pushkar Gold D, Cohen C, Shulman K, Zucchero C, Andres D, Etezadi J (1995) Caregiving and dementia: predicting negative and positive outcomes for caregivers. Int J Aging Hum Dev 41: 183–201. pmid:8666465
- 74. Reis MF, Gold DP, Andres D, Markiewicz D, Gauthier S (1994) Personality traits as determinants of burden and health complaints in caregiving. Int J Aging Hum Dev 39: 257–271. pmid:7875917
- 75. Ryan KA, Weldon A, Persad C, Heidebrink JL, Barbas N, Giordani B (2012) Neuropsychiatric Symptoms and Executive Functioning in Patients with Mild Cognitive Impairment: Relationship to Caregiver Burden. Dement Geriatr Cogn Disord 34: 206–215. pmid:23128102
- 76. Shieh SC, Tung HS, Liang SY (2012) Social support as influencing primary family caregiver burden in Taiwanese patients with colorectal cancer. Journal of Nursing Scholarship 44: 223–231. pmid:22726108
- 77. Son GR, Wykle ML, Zauszniewski JA (2003) Korean adult child caregivers of older adults with dementia. Predictors of burden and satisfaction. J Gerontol Nurs 29: 19–28. pmid:12596334
- 78. Stevens LF, Perrin PB, Gulin S, Rogers H, Villasenor Cabrera T, Jimenez-Maldonado M, et al. (2013) Examining the Influence of Three Types of Social Support on the Mental Health of Mexican Caregivers of Individuals with Traumatic Brain Injury. Am J Phys Med Rehabil. pmid:23552337
- 79. Teixeira RJ, Pereira MG (2013) Psychological morbidity, burden, and the mediating effect of social support in adult children caregivers of oncological patients undergoing chemotherapy. Psychooncology 22: 1587–1593. pmid:22972765
- 80. Vérez Cotelo N, Andrés Rodriguez NF, Fornós Perez JA, Andrés Iglesias JC, Rios Lago M (2015) Burden and associated pathologies in family caregivers of Alzheimer’s disease patients in Spain. Pharm Pract (Granada) 13: 521.
- 81. Wang LC, Chen WY, Chang SC, Wong ON, Hong RJ, Wang RH (2011) [Caregiving burden and associated factors among caregivers of terminally ill gastrointestinal cancer patients]. Hu li za zhi 58: 54–64. pmid:22113634
- 82. Yüksel MM (2013) The well-being of siblings of patients with schizophrenia: an evaluation within the transactional stress and coping model. Ankara: Middle East Technical University.
- 83. Yurtsever S, Özge A, Kara A, Yandim A, Kalav S, Yesil P (2013) The relationship between care burden and social support in Turkish Alzheimer patients family caregivers: Cross-sectional study. Journal of Nursing Education and Practice 3: 1.
- 84. Adriaansen JJ, van Leeuwen CM, Visser-Meily JM, van den Bos GA, Post MW (2011) Course of social support and relationships between social support and life satisfaction in spouses of patients with stroke in the chronic phase. Patient Educ Couns 85: e48–52. pmid:21232903
- 85. Dorfman LT, Holmes CA, Berlin KL (1996) Wife caregivers of frail elderly veterans: Correlates of caregiver satisfaction and caregiver strain. Family Relations 45: 46–55.
- 86. Greene MC, Zhang J, Li J, Desai M, Kershaw T (2013) Mental health and social support among HIV-positive injection drug users and their caregivers in China. AIDS Behav 17: 1775–1784. pmid:23283579
- 87. Losada A, Marquez-Gonzalez M, Knight BG, Yanguas J, Sayegh P, Romero-Moreno R (2010) Psychosocial factors and caregivers’ distress: Effects of familism and dysfunctional thoughts. Aging and Mental Health 14: 193–202. pmid:20336551
- 88. Meiland FJM, Danse JAC, Wendte JF, Klazinga NS, Gunning-Schepers LJ (2001) Caring for relatives with dementia—caregiver experiences of relatives of patients on the waiting list for admission to a psychogeriatric nursing home in The Netherlands. Scandinavian Journal of Public Health 29: 113–121. pmid:11484863
- 89. Riemsma RP, Taal E, Rasker JJ, Klein G, Bruyn GA, Wouters JM, et al. (1999) The burden of care for informal caregivers of patients with rheumatoid arthritis. Psychology and Health 14: 773–794.
- 90. Robinson KM (1990) Predictors of burden among wife caregivers. Sch Inq Nurs Pract 4: 189–203; discussion 205–188. pmid:2274731
- 91. Rodakowski J, Skidmore ER, Rogers JC, Schulz R (2012) Role of social support in predicting caregiver burden. Arch Phys Med Rehabil 93: 2229–2236. pmid:22824248
- 92. Spaid WM, Barusch AS (1994) Emotional closeness and caregiver burden in the marital relationship. Journal of Gerontological Social Work 21: 197–211.
- 93. Stommel M, Given CW, Given B (1990) Depression as an overrriding variable explainig caregiver burdens. Journal of Aging and Health 2: 81–102.
- 94. Tang Y (2006) Obligation of filial piety, adult child caregiver burden, received social support, and psychological wellbeing of adult child caregivers for frail elderly people in Guangzhou, China. Hong Kong: University of Hong Kong.
- 95. Burton AM, Haley WE, Small BJ, Finley MR, Dillinger-Vasille M, Schonwetter R (2008) Predictors of well-being in bereaved former hospice caregivers: the role of caregiving stressors, appraisals, and social resources. Palliative and Supportive Care 6: 149–158. pmid:18501050
- 96. Cheng ST, Lam LC, Kwok T, Ng NS, Fung AW (2013) The social networks of Hong Kong Chinese family caregivers of Alzheimer’s disease: correlates with positive gains and burden. Gerontologist 53: 998–1008. pmid:23371974
- 97. Folkman S, Chesney MA, Cooke M, Boccellari A, Collette L (1994) Caregiver burden in HIV-positive and HIV-negative partners of men with AIDS. J Consult Clin Psychol 62: 746–756. pmid:7962878
- 98. Prati G, Pietrantoni L (2010) The relation of perceived and received social support to mental health among first responders: a meta-analytic review. Journal of Community Psychology 38: 403–417.
- 99. Zegwaard MI, Aartsen MJ, Cuijpers P, Grypdonck MH (2011) Review: a conceptual model of perceived burden of informal caregivers for older persons with a severe functional psychiatric syndrome and concomitant problematic behaviour. Journal of Clinical Nursing 20: 2233–2258. pmid:21332854
- 100. Dam AE, de Vugt ME, Klinkenberg IP, Verhey FR, van Boxtel MP (2016) A systematic review of social support interventions for caregivers of people with dementia: Are they doing what they promise? Maturitas 85: 117–130. pmid:26857890
- 101. Elvish R, Lever S-J, Johnstone J, Cawley R, Keady J (2013) Psychological interventions for carers of people with dementia: A systematic review of quantitative and qualitative evidence. Lutterworth, Leicestershire: British Association for Counselling & Psychotherapy. 106–125 p.