Research in Cardiovascular Medicine

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 9  |  Issue : 2  |  Page : 35--41

Evaluation of the reliability and validity of the Iranian caregiver burden questionnaire for heart failure


Marjohn Hamediseresht, Yasaman Khalili, Raana Asghari, Sepideh Taghavi, Ahmad Amin, Nasim Naderi 
 Rajaie Cardiovascular Medical and Research Center, Tehran, Iran

Correspondence Address:
Dr. Yasaman Khalili
Rajaie Cardiovascular Medical and Research Center, Valiasr Ave, Hashemi Rafsanjani Blvd, Tehran
Iran

Abstract

Introduction: It is important to have a strong appropriate tool for measuring, evaluating, and understanding the nature and consequences of chronic stresses on caregivers of patients with heart failure (HF). The purpose of this study is the assessment of the validity and reliability of the questionnaire for evaluating the burden on caregivers of patients with HF. Methods: In order to assess the burden of caregivers of patients with HF, the Caregiver Burden Questionnaire for Heart Failure version 3 (CBQ-HF, version 3) was used. After translation and back translation, the questionnaire was provided to 20 caregivers, and after 2 weeks, the same caregivers refilled the questionnaire; so that, we could measure its reliability by calculating Cronbach's alpha. Face validity and content validity were also obtained at this stage. Finally, the questionnaire was provided to eighty caregivers; hence, the total number of one hundred caregivers completed the questionnaire. Results: From a total of 100 collected questionnaires, 68 of participants were male and 32 of participants were female. The mean ± standard deviation of emotional burden on the patient's caregivers was 46 ± 10 and the median of the physical, social, and living pattern burden was 14, 4, and 13, respectively. The test–retest reliability showed high internal consistency (Cronbach's alpha: 94%). Conclusion: This study approved the Persian version of CBQHF questionnaire as a standard and valid tool in Persian language, which can be used among caregivers of patients with HF in order to examine their problems and to plan for improving their quality of life.



How to cite this article:
Hamediseresht M, Khalili Y, Asghari R, Taghavi S, Amin A, Naderi N. Evaluation of the reliability and validity of the Iranian caregiver burden questionnaire for heart failure.Res Cardiovasc Med 2020;9:35-41


How to cite this URL:
Hamediseresht M, Khalili Y, Asghari R, Taghavi S, Amin A, Naderi N. Evaluation of the reliability and validity of the Iranian caregiver burden questionnaire for heart failure. Res Cardiovasc Med [serial online] 2020 [cited 2020 Nov 30 ];9:35-41
Available from: https://www.rcvmonline.com/text.asp?2020/9/2/35/290864


Full Text



 Introduction



The quality of life in patients with heart failure (HF) is significantly impaired. Physical limitations caused by this chronic disease and its continuation can lead to restriction of social activities and the emergence of emotional problems in the patients.[1] Management of all factors that cause inability in the patients with HF is of particular importance and the main part of this burden is on the family members and relatives who have the responsibility of caring these patients.[2],[3]

Caregivers usually assist patients on their daily routines without expecting any payment or reward, and their role is especially prominent in the cases of severe illness or significant functional impairment.[4] The effective and powerful role of the caregivers of the patients with HF is evident in the improvement of their quality of life,[5] decrease in the hospitalization rate, and reduction of the morbidity in these patients.[6],[7],[8]

Providing effective and regular care to patients with HF may be accompanied by emergence of some disorders in the health and quality of life of these caregivers.[9],[10],[11]

Studies have shown that caregivers of patients with HF may experience the emotional and physical pressures as well as the caregivers of patients with chronic lung disease or advanced cancer.[12],[13]

There are few studies about the burden imposed on the family members of patients with HF and also the challenges they may encounter. Moreover, most studies have been conducted on the burden on caregivers of the patients affected by chronic diseases other than HF. For example, several studies have evaluated the burden on caregivers who take care of dialysis patients [14] and also examined the effect of participation of family members in supportive groups for caregiver of patients with Alzheimer [15] or the effect of educating family members on reducing the burden on caregivers of the patients with mental disorder, but very limited studies have been done on the caregivers of HF patients.

In developing countries like Iran, the health system is still focused on the medical requirements of the patient. The health-care provider systems, especially the nurses, are not aware about the cares given to the patients at home, while this issue can harm patients and their caregivers. Hence, researchers are interested to assess the amount of pressure imposed on family members and caregivers of patients with HF in order to reduce it via introducing appropriate strategies and therefore decrease some burden of the disease.[16]

As mentioned earlier, the burden on the family members of the patients with HF has rarely been investigated, and factors that affect this pressure have been less evaluated. In Iran, the majority of studies have evaluated nursing of patients with HF and more focused on the quality of life,[17] educating the needs,[18] and familiarizing the patients with HF about their care,[19] while emphasizing on family members of patient and facing challenges are important issue that should be addressed. To understand the nature and consequences of chronic disease burden on caregivers, it is important to have an appropriate and capable instrument for measuring and evaluating.[20],[21]

The results of qualitative studies show that family members of the patients with HF experience several challenges due to the high rate of hospitalization of these patients.

Several studies have been conducted in Western countries to assess the burden and pressure imposed on caregivers of patients with HF that pertains to physical, psychological, educational, and financial needs of them;[22],[23],[24],[25],[26] however, there is scarcity in such studies in Iran.

The aim of this study is to determine the reliability and validity of Iranian version of Caregiver Burden Questionnaire-HF (CBQ-HF).

 Methods



We included all patients with definite diagnosis of HF (reduced or preserved ejection fraction [EF]) who were presented at clinic or were hospitalized.

The study was approved by the Ethics Committee and obtained ethic code which was IR.IUMS.FMD.REC1396. 9411171008. The study was approved in research and ethics committee of Iran university of medical sciences with an ethical registration number of 9411171008. In order to assess the burden of caregivers of patients with HF, CBQ-HF version 3 was used as the main questionnaire for data gathering. The questionnaire consisted of 26 specific questions that assessed the severity of the patient's experiences in the last 4 weeks in four areas of psychological (15 items), physical (5 items), social (2 items), and lifestyle (4 items), assessing the burden on caregivers of patients with HF in 5-point Likert-type scale. For each domain, the mean of each domain was considered as the total score of that domain. Higher score indicated greater burden.

After receiving permission from the author, the questionnaire was translated into Persian, and then the Persian version was translated into English (back translation) by a translator who was fluent in English and all discrepancies were resolved. The final translated Persian version was prepared as a set of simple and specific questions to be comprehensible to all caregivers with any level of literacy and was provided to 100 caregivers of patients with HF. After completing the informed consent form by patients, they were asked to complete the questionnaire according to the real facts. The translated version was first provided to 20 caregivers of the HF patients. After 2 weeks, the questionnaire was filled again by the same caregivers and its reliability and internal consistency were calculated by Cronbach's alpha. The face validity of the questionnaire was obtained through interview with the participants and HF specialists. In the second stage, the questionnaire was provided to caregivers of patients with HF and the scores of each domain were calculated separately. The quantitative variables of the questionnaire were classified into four main categories:

The physical burden on the caregiversThe psychoemotional burden on the caregiversThe social burden on the caregiversThe burden on the lifestyle of caregivers.

We also collected some demographic and clinical characteristics of the patients, which consist of sex, level of education, New York Heart Association Functional Class (NYHA Class) and EF which was obtained from the last recorded echocardiography. Information about serious comorbidities which could impact on the course of their disease were collected including diabetes mellitus, hypertension, chronic obstructive pulmonary disease (according to patient's medical records), renal failure and anemia (according to lab data), osteoarthritis, atrial fibrillation (based on previous or current electrocardiography or halter monitoring), depression and anxiety based on a psychiatrist's diagnosis and obesity based on the National Institutes of Health definition (body mass index equal or greater than 30).

Data were analyzed using SPSS version 23 (Armonk, NY: IBM Corp) categorical variables were presented as counts with percentages, while continuous variables were expressed as means ± standard deviation (SD) or as median values with interquartile range depending on normality of distributions. Internal consistency of Parkinson's Disease Questionnaire-39 was reported by Cronbach's alpha's test, Mann–Whitney, Chi-square, ANOVA, and Kruskal–Wallis tests which were used to assess the scores in the groups of the study.

 Results



Based on the analysis done on the obtained data, reliability of the Persian questionnaire was calculated by Cronbach's alpha test. The result of the test was 94%, which indicates high internal validity. One hundred of caregivers of patients with HF were included in this study. Demographic characteristics of the patients are shown in [Table 1]. Of all participants, 68 were male and 32 were female. Regarding their marital status, 13 of them were single and 87 were married. About the level of education, 35 participants had primary school education, 36 had high school, and 28 participants had academic which includes 18 bachelors and 10 master. Level of education in one person was unknown.{Table 1}

Regarding the life situation of caregivers, 68 persons lived both with other family members and the patient, 19 lived without patients, and 13 lived alone with the patients.

Regarding the heart functional class, the patients were classified into four stages according to NYHA classification system and the frequency of patients' functional class and also the comorbidities are shown in [Table 2]. Calculated Cronbach's alpha revealed high internal consistency (0.94). Consistency for three domains were above 0.7; the lowest figure, however, measured in social lifestyle (0.63) [Table 3].{Table 2}{Table 3}

As the caregivers were well aware of the questions during answering, and had no difficulty in understanding the questions, we can conclude that the content validity of this questionnaire was also high.

The average of psychoemotional burden on caregivers of patients with failure (mean ± SD) was 3.08 ± 0.69. The median and interquartile range of physical burden, social burden, and lifestyles burden of the caregivers were 2.8 (2–3.6(, 2 )1.5–3), and 3.25 (2.25–4.25), respectively.

The result of independent t- test showed no difference in psychoemotional burden of caregivers between two genders (3.05 ± 0.65 and 3.09 ± 0.71) in men and women, respectively (P = 0.78). The median of physical burden, social burden, psychoemotional burden, and burden of lifestyle regarding the demographic characteristic of caregivers is presented in [Table 4].{Table 4}

According to the obtained data, marital status had a significant association with the social burden and lifestyle of the caregiver (P = 0.03 and 0.003, respectively).

Ninety-two have specified the years passed of diagnosis of their disease with a mean and SD of 6.7 ± 7.7. A correlation test was used to determine the relationship between the duration of illness years passed after disease diagnosis and the burden on the caregivers of the patients. There was no significant correlation between the duration of illness of patients and all four domains of their caregivers' burden (P value was between 0.23 and 0.94).

Based on the obtained data, 94 caregivers specified the duration of patient care per week and the mean and SD of the time of care per week was 119.5 ± 65.1 h.

A correlation test was conducted to determine the relationship between weekly care hours in patients with defined areas. None of the provided correlation tests were significant: social burden (P = 0.52), psychoemotional burden (P = 0.41), physical burden (P = 0.3), and the burden on the lifestyle (P = 0.73). Furthermore, the association between family relationship of caregiver with patients with defined areas was not meaningful for social burden (P = 0.05), psychoemotional burden (P = 0.28), physical burden (P = 0.40), and the burden on the lifestyle (P = 0.18).

In the analysis, the relationship between anxiety and depression of patients with burden on caregivers was evaluated by Mann–Whitney and t-test. The results are shown in [Table 5] and [Table 6].{Table 5}{Table 6}

Based on the analysis done on the NYHA Class, patients were evaluated in four groups defined by burden on caregivers in four areas which are shown in [Table 6].

Burden on the caregivers was assessed based on NYHA classes, which was predefined into four groups [Table 7].{Table 7}

Based on the performed analysis, the NYHA Class of the patients had a significant association with the burden on the lifestyle (P = 0.016) and physical burden on the caregivers (P = 0.039).

Based on the analysis performed by the Mann–Whitney test, the following findings were obtained:

There was a significant difference among the physical burdens of the caregivers in NYHA Class 1 and the Class 4 (P = 0.03) and NYHA Class 2 and the Class 4 (P = 0.04).

Furthermore, there was a significant difference in burden on the caregivers of patients in the NYHA Class 1 and Class 2 (P = 0.008) and NYHA Class 1 and Class 4 (P = 0.003).

 Discussion



The primary objective of this study was to assess the validity and reliability of Persian version of CBQ-HF.

In this study, the social burden and burden on the lifestyle of caregivers were significantly different between married and single caregivers (P = 0.03 and 0.003, respectively). It indicates that marriage itself has a separate responsibility and role for caregivers because married people, apart from being responsible for their patient, have separate roles as spouse, mother, or father and it can increasingly affect the burden on social life and lifestyle. They may not have enough time to follow their own plans and especially if they are not supported by other family members, their multiple responsibilities will increase. Other studies that have been conducted within the field of HF indicate increased levels of psychosocial distress,[27],[28],[29] decreased levels of well-being,[30],[31] and impaired quality of life [32] among caregivers.

Furthermore, unlike expected, our findings showed that the number of years passed from the time of HF diagnosis does not have significant association with none of CBQ-HF domains. Accordingly, Saunders showed that the age of the caregiver, years of care, and hours of care per day do not influence the burden of the caregivers.[33]

Hours of patient care in each week were not significantly correlated with none of the domains according to the correlation test. In contrast to what was thought, the amount of anxiety and depression of patients were not significantly associated with four burden domains. While in a study published in 2005 by Hooley et al., the association between depression and the burden on caregivers was statistically significant (P < 0.05).[10]

The study showed differences in lifestyle and physical burden among caregivers based on patient's NYHA classes which was seen between class (1 and 2,1and 4) and (1and 4,2 and 4) Several studies have shown that taking care of patients with chronic medical conditions leads to various physical and emotional problems in caregivers.[7] In a study by Schulz and Beach in 1999, after adjusting for socioeconomic factors and demographic characteristics and subclinical cardiovascular diseases, the caregiver group showed a higher mortality rate than the control group.[34] Moreover, in a study published by Pressler et al., in 2013, the caregivers of patients in more advanced stages of heart failure, had greater responsibility, higher level of anxiety and lower quality of life compared to caregivers of patients in lower stages of heart failure.[35]

According to a study by Kim et al. in 2011, as the caregivers take more responsibilities and tasks, they will experience higher levels of pressure alongside other negative factors such as increasing the sense of responsibility, to improve patients' well-being and spend more time to care for them.[36]

According to Lee et al.'s study, a group of caregivers with higher level of satisfaction were those who had good relationship with the patients.[37] An issue that could increase the enthusiasm in the caregivers moreover, is helpful to prevent experiencing depression. One study in China has found that caregivers who were adult children expressed the highest level of burden among all primary family caregivers.[38] Findings from prior studies in this area were inconsistent with this study. Data were in agreement with results of one study,[39] but others reported that spousal caregivers suffered the most.[15],[36] Adult children are more likely to suffer a higher caregiver burden due to conflicts between their caregiving tasks, careers, and nuclear families.[40] In this study, most caregivers were adult children who were employed. Employment outside the home was associated with an additional burden because of conflicts between working and caregiving tasks.[41]

In our study, there was no significant relationship between the relation of caregivers with patient's psychoemotional burden, social burden, physical burden, and burden on lifestyle.

The proper care of the caregiver can also reduce the negative effects of caring to the patients, such as anger and anxiety.[2],[3]

However, on the other hand, caregivers also offer positive aspects of patient care. A deep sense of personal satisfaction, increased self-esteem, and the expectation of receiving worldly and future rewards in return for caring for a patient with a debilitating disorder, is one of the issues raised by the caregivers [4],[42] and can be a major driving force to continue caring and to endure hard situations. Sautter et al. reported a high level of self-esteem among caregivers in their study on this issue. This can be considered as a valuable goal in the health-care system, in which the strengthening of the positive aspects of patient care can diminish the negative outcomes and thereby ensure a suitable life for individuals and improve the effectiveness of cares.[5]

Financial issues are another important topic affecting the quality of patient care. Financial pressure enhances by increased cost of treatment of patients with HF often makes caregivers to spend about 10% of their annual income to cover patient-related costs, which puts them in a double burden.[42] As a result, the heavy financial burden might increase the caregiver burden. Proposed strategies to relieve the caregiver burdens in low-income districts include adding government financial support, expanding the coverage of medical insurance, and providing more resources.

Knowing the positive outcomes of patient care, one of the limitations of the CBQ-HF questionnaire is that this questionnaire only examines the negative effects of patient care. Some articles have reported that caregivers may even enjoy caring someone who love.[6],[7] Although in the initial version of this questionnaire, it was agreed that positive aspects of patient care were not a primary goal, some positive effects were reported in a few number of participants during the initial conceptual studies.[8] Therefore, it should be noted that more qualitative research is required to obtain sufficient information from the positive aspects of patients' care and it is necessary to include additional items in the questionnaire in order to identify these aspects and ensure that the questions are comprehensively addressed. Such questionnaire can measure the full range of patient experiences.

Regarding the importance of economic issues, another limitation of the CBQ questionnaire is the failure to consider financial issues and its pressures on the patients. This issue is important, especially in developing countries such as Iran with low gross domestic product and limited coverage of insurance, and it can be more complicated under the shadow of aggravating economic situation in our country.

In addition, it should be noticed that when the CBQ-HF questionnaire is designed to evaluate the “subjective burden” of caregivers and does not examine the objective burden on the caregivers. We suggest that simultaneous evaluation of both objective and objective categories to be considered in order to evaluate all aspects of the experiences and conditions of caregivers. For example, a subjective questionnaire (such as CBQ-HF) can be used with an objective questionnaire (Dutch Objective Burden Inventory) for comprehensive and complete patient burden.[23],[43]

 Conclusion



Iranian version of CBQ- HF (version3) has high reliability and face validity and can be used confidentially to assess the burden of caregivers of heart failure patients.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Dunderdale K, Thompson DR, Miles JN, Beer SF, Furze G. Quality-of-life measurement in chronic heart failure: Do we take account of the patient perspective? Eur J Heart Fail 2005;7:572-82.
2Luttik ML, Jaarsma T, Veeger N, Tijssen J, Sanderman R, van Veldhuisen DJ. Caregiver burden in partners of heart failure patients; limited influence of disease severity. Eur J Heart Fail 2007;9:695-701.
3Pressler SJ, Gradus-Pizlo I, Chubinski SD, Smith G, Wheeler S, Wu J, et al. Family caregiver outcomes in heart failure. Am J Crit Care 2009;18:149-59.
4Kang X, Li Z, Nolan MT. Informal caregivers' experiences of caring for patients with chronic heart failure: Systematic review and metasynthesis of qualitative studies. J Cardiovasc Nurs 2011;26:386-94.
5Bennett SJ, Perkins SM, Lane KA, Deer M, Brater DC, Murray MD. Social support and health-related quality of life in chronic heart failure patients. Qual Life Res 2001;10:671-82.
6Chin MH, Goldman L. Correlates of early hospital readmission or death in patients with congestive heart failure. Am J Cardiol 1997;79:1640-4.
7Krumholz HM, Butler J, Miller J, Vaccarino V, Williams CS, Mendes de Leon CF, et al. Prognostic importance of emotional support for elderly patients hospitalized with heart failure. Circulation 1998;97:958-64.
8Coyne JC, Rohrbaugh MJ, Shoham V, Sonnega JS, Nicklas JM, Cranford JA. Prognostic importance of marital quality for survival of congestive heart failure. Am J Cardiol 2001;88:526-9.
9Šgren S, Evangelista L, Davidson T, Strömberg A. The influence of chronic heart failure in patient-partner dyads – A comparative study addressing issues of health-related quality of life. J Cardiovasc Nurs 2011;26:65-73.
10Hooley PJ, Butler G, Howlett JG. The relationship of quality of life, depression, and caregiver burden in outpatients with congestive heart failure. Congest Heart Fail 2005;11:303-10.
11Garlo K, O'Leary JR, van Ness PH, Fried TR. Burden in caregivers of older adults with advanced illness. J Am Geriatr Soc 2010;58:2315-22.
12Burton AM, Sautter JM, Tulsky JA, Lindquist JH, Hays JC, Olsen MK, et al. Burden and well-being among a diverse sample of cancer, congestive heart failure, and chronic obstructive pulmonary disease caregivers. J Pain Symptom Manage 2012;44:410-20.
13Clark AM, Reid ME, Morrison CE, Capewell S, Murdoch DL, McMurray JJ. The complex nature of informal care in home-based heart failure management. J Adv Nurs 2008;61:373-83.
14Cantekin I, Kavurmacı M, Tan M. An analysis of caregiver burden of patients with hemodialysis and peritoneal dialysis. Hemodialysis Int 2016;20:94-7.
15Germain S, Adam S, Olivier C, Cash H, Ousset PJ, Andrieu S, et al. Does cognitive impairment influence burden in caregivers of patients with Alzheimer's disease? J Alzheimer's Disease 2009;17:105-14.
16Bahrami M, Etemadifar S, Shahriari M, Farsani AK. Caregiver burden among Iranian heart failure family caregivers: A descriptive, exploratory, qualitative study. Iran J Nurs Midwifery Res 2014;19:56-63.
17Rafii F, Shahpoorian F, Naasher Z, Azarbaad M, Hosseini F. The importance of learning needs of CHF patients from patients' and nurses' perspective. Iran J Nurs 2009;22:19-30.
18Habibollahzade H, Baghaei R, Abolfathi L, Gasemzade P. Study on causes of heart failure and evaluation of knowledge and attitude towards the disease. J Med Counc Islamic Repub Iran 2001;19:85-9.
19U.S. Department of Health and Human Services FDA Center for Drug Evaluation and Research, U.S. Department of Health and Human Services FDA Center for Biologics Evaluation and Research, U.S. Department of Health and Human Services FDA Center for Devices and Radiological Health. Guidance for industry: Patient-reported outcome measures: Use in medical product development to support labeling claims: Draft guidance. Health Qual Life Outcomes 2006;4:79.
20Use CfMPfH. Reflection Paper on the Regulatory Guidance for the Use of Health-Related Quality of Life (HRQL) Measures in the Evaluation of Medicinal Products. London: European Medicines Agency; 2005.
21Nauser JA, Bakas T, Welch JL. A new instrument to measure quality of life of heart failure family caregivers. J Cardiovasc Nurs 2011;26:53-64.
22Dunbar SB, Clark PC, Quinn C, Gary RA, Kaslow NJ. Family influences on heart failure self-care and outcomes. J Cardiovasc Nurs 2008;23:258-65.
23Clark AM, Freydberg CN, McAlister FA, Tsuyuki RT, Armstrong PW, Strain LA. Patient and informal caregivers' knowledge of heart failure: Necessary but insufficient for effective self-care. Eur J Heart Fail 2009;11:617-21.
24Hupcey JE, Fenstermacher K, Kitko L, Fogg J. Palliative needs of spousal caregivers of patients with heart failure followed at specialized heart failure centers. J Hosp Palliat Nurs 2011;13:142-50.
25Agren S, Evangelista L, Strömberg A. Do partners of patients with chronic heart failure experience caregiver burden? Eur J Cardiovasc Nurs 2010;9:254-62.
26Lum HD, Lo D, Hooker S, Bekelman DB. Caregiving in heart failure: Relationship quality is associated with caregiver benefit finding and caregiver burden. Heart Lung 2014;43:306-10.
27Pinquart M, Sörensen S. Differences between caregivers and noncaregivers in psychological health and physical health: A meta-analysis. Psychol Aging 2003;18:250-67.
28Karmilovich SE. Burden and stress associated with spousal caregiving for individuals with heart failure. Prog Cardiovasc Nurs 1994;9:33-8.
29Rohrbaugh MJ, Cranford JA, Shoham V, Nicklas JM, Sonnega JS, Coyne JC. Couples coping with congestive heart failure: Role and gender differences in psychological distress. J Fam Psychol 2002;16:3-13.
30Dracup K, Evangelista LS, Doering L, Tullman D, Moser DK, Hamilton M. Emotional well-being in spouses of patients with advanced heart failure. Heart Lung 2004;33:354-61.
31Evangelista LS, Dracup K, Doering L, Westlake C, Fonarow GC, Hamilton M. Emotional well-being of heart failure patients and their caregivers. J Card Fail 2002;8:300-5.
32Luttik ML, Jaarsma T, Veeger NJ, van Veldhuisen DJ. For better and for worse: Quality of life impaired in HF patients as well as in their partners. Eur J Cardiovasc Nurs 2005;4:11-4.
33Saunders MM. Indicators of health-related quality of life in heart failure family caregivers. J Community Health Nurs 2009;26:173-82.
34Schulz R, Beach SR, Ives DG, Martire LM, Ariyo AA, Kop WJ. Association between depression and mortality in older adults: the Cardiovascular Health Study. Arch Int Med 2000;160:1761-8.
35Pressler SJ, Gradus-Pizlo I, Chubinski SD, Smith G, Wheeler S, Sloan R, et al. Family caregivers of patients with heart failure: A longitudinal study. J Cardiovasc Nurs 2013;28:417-28.
36Kim H, Chang M, Rose K, Kim S. Predictors of caregiver burden in caregivers of individuals with dementia. J Adv Nurs 2012;68:846-55.
37Lee CS, Vellone E, Lyons KS, Cocchieri A, Bidwell JT, D'Agostino F, et al. Patterns and predictors of patient and caregiver engagement in heart failure care: a multi-level dyadic study. Int J Nurs Stud 2015;52:588-97.
38Hu X, Dolansky MA, Hu X, Zhang F, Qu M. Factors associated with the caregiver burden among family caregivers of patients with heart failure in southwest China. Nurs Health Sci 2016;18:105-12.
39Reed C, Belger M, Dell'agnello G, Wimo A, Argimon JM, Bruno G, et al. Caregiver Burden in Alzheimer's Disease: Differential Associations in Adult-Child and Spousal Caregivers in the GERAS Observational Study. Dement Geriatr Cogn Dis Extra 2014;4:51-64.
40Pinquart M, Sörensen S. Associations of caregiver stressors and uplifts with subjective well-being and depressive mood: A meta-analytic comparison. Aging Ment Health 2004;8:438-49.
41Duxbury L, Higgins C, Smart R. Elder care and the impact of caregiver strain on the health of employed caregivers. Work 2011;40:29-40.
42Curtis HS. Exploring the Effects of Caring for Congestive Heart Failure Patients on Caregiver Well-Being: A Descriptive Study; 2017.
43Saunders MM. Factors associated with caregiver burden in heart failure family caregivers. West J Nurs Res 2008;30:943-59.