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Types of social support and their relationships to physical and depressive symptoms and health-related quality of life in patients with heart failure
Heart & Lung xxx (2014) 1e7
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Types of social support and their relationships to physical and depressive symptoms and health-related quality of life in patients with heart failure Seongkum Heo, PhD, RN a, *, Terry A. Lennie, PhD, RN b, Debra K. Moser, DNSc, RN b, Robert L. Kennedy, PhD c a b c
University of Arkansas for Medical Sciences College of Nursing, 4301 W. Markham Street #529, Little Rock, AR 72205, USA University of Kentucky, Lexington, USA Office of Educational Development, University of Arkansas for Medical Sciences, Little Rock, USA
a r t i c l e i n f o
a b s t r a c t
Article history: Received 31 October 2013 Received in revised form 14 April 2014 Accepted 18 April 2014 Available online xxx
Objectives: To examine the various types of social support associated with physical and depressive symptoms and health-related quality of life (HRQOL) in patients with heart failure (HF) and the mediating effects of symptoms on the relationship between social support and HRQOL. Background: Patients with HF have a high burden of physical and depressive symptoms, along with poor HRQOL. Social support may improve symptoms and HRQOL. Methods: Data on social support (marital status, family relationships, relationships with health care providers, social networks, emotional support, and instrumental support), symptoms, and HRQOL were collected from 71 patients. Hierarchical regression was used to analyze the data. Results: Emotional support was related to all physical and depressive symptoms and HRQOL. Physical and depressive symptoms mediated the relationship between emotional support and HRQOL. Conclusions: Further studies are needed to identify ways to improve emotional support and determine whether the improvement leads to improvements in symptoms and HRQOL. Ó 2014 Elsevier Inc. All rights reserved.
Keywords: Heart failure Social support Emotional support Symptoms Quality of life
Introduction Health-related quality of life (HRQOL) is poorer in patients with heart failure (HF) than in healthy populations and in patients with other chronic diseases.1e3 Heart failure symptoms, including dyspnea and fatigue, and depressive symptoms are prevalent in this population and are strongly associated with poor HRQOL.3e7 Physical symptoms can prevent patients with HF from performing their daily activities that lead to poor HRQOL.8 For instance, many patients with HF have New York Heart Association (NYHA) functional class IIeIV,9 indicating that they experience HF symptoms when they perform daily activities.10 In addition, depressive symptoms also can cause functional impairment that leads to poor HRQOL in this population. For example, depressed patients with HF had reduced daily activities and walking distance compared to non-depressed patients.11 Thus, to improve
Abbreviations: HF, Heart failure; HRQOL, Health-related quality of life; NYHA, New York Heart Association. * Corresponding author. Tel.: þ1 501 686 5375; fax: þ1 501 296-1765. E-mail address: [email protected] (S. Heo). 0147-9563/$ e see front matter Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.hrtlng.2014.04.015
outcomes, it is important to identify modifiable factors affecting symptoms and HRQOL. The revised Wilson and Clearly model suggests that social support may be related to both symptoms and HRQOL.12 Social support may affect physical symptoms through effects on self-care. For instance, social support is associated with adherence to medication treatment and following a low sodium diet,13e15 and lack of adherence to medication treatment and a low sodium diet is associated with more severe symptom burden and higher hospitalization rates.16,17 Heart failure symptoms are important antecedents of hospitalizations in this population.4 Social support has also been associated with depressive symptoms in patients with HF.18 However, the findings on relationships between social support and HRQOL have been inconsistent. Patients with HF have reported that social support was a factor affecting their HRQOL,19 and perceived quality of support has been associated with HRQOL.20 However, the majority of HF studies that have examined the relationships between social support and HRQOL found that these relationships were not significant.21e24 These contradictory findings, in part, may be due to differing effects of different types of social support on HRQOL.
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Social support in HF studies has been conceptualized in many ways, varying from simple structural support (e.g., marital status) to comprehensive combinations of structural and functional support.20e22,25,26 Structural support refers to the existence of a social network and the features of contacts with the network (e.g., marital status and social network).27,28 Martial status refers to a very simple social network with spouse or cohabitant (Fig. 1). Social networks represent a wider range of social networks that extend beyond marital status, including more extended family members, friends, and society. Functional support refers to individuals’ perceptions of the resources that social networks provide (e.g., emotional support, instrumental support, and relationships to health-care providers).27,28 Emotional support refers to intangible support from others except health care providers. Instrumental support refers to tangible support from others. Relationships to health care providers represent support from health care providers. Family relationships may combine structural and functional support because they include not only the existence of a social network but also individuals’ perceptions of the resources that family relationships provide. These different types of structural and functional support may affect symptoms and, in turn, HRQOL differently. The relationships between different types of social support and physical symptoms in patients with HF have been rarely examined. However, a meta-analysis that examined the relationship between different types of support and adherence to medical treatment found that instrumental support had the strongest association with adherence.25 In addition, adherence to medical treatment was greater in patients from cohesive families than in patients from families in conflict.25 In another study,29 patients with HF perceived health care providers as one source of support for medication adherence. Thus, instrumental support, family relationship, and relationships with health care providers may affect self-care, and, in turn, physical symptoms. Relationships between social support and depressive symptoms have been examined in this population. Among different types of structural and functional support, living with families and greater emotional support were the only variables significantly associated with less severe depressive symptoms.30 Finally, relationships between social support and HRQOL have been examined in this population, and the findings were inconsistent. In one study,20 one type of functional support (perceived quality of support), but not another type of functional support (emotional support), was associated with HRQOL. In two other studies,21,22 a combination of different types of structural and functional support was not associated with HRQOL.
One reason for the lack of relationship of social support to HRQOL in HF studies may be that social support affects HRQOL mainly through its effects on other variables, including physical and depressive symptoms.12 If social support is associated with HRQOL indirectly through its effects on physical symptoms and depressive symptoms, this may explain the lack of direct, independent associations between social support and HRQOL in patients with HF.21e23 Thus, examination of direct and indirect associations of social support with HRQOL will provide valuable information on the theoretical framework of HRQOL and the associating factors. Therefore, we examined the relationships of several types of social support (marital status, social networks, relationships with health care providers, emotional support, instrumental support, and family relationships) to physical symptoms (dyspnea, fatigue, chest pain, edema, sleeping difficulty, and dizziness), depressive symptoms, and HRQOL. We also explored the mediating effects of physical and depressive symptoms on the relationship between social support and HRQOL in patients with HF. Methods Design, setting, and sample A cross-sectional correlational design was used to examine the relationships of social support to physical symptoms, depressive symptoms, and HRQOL in a convenience sample of patients with HF. Institutional Review Board approval was obtained for the current study. Eligible patients were referred to research associates by physicians or nurse practitioners in the HF clinic and then approached by the research associates who were trained in questionnaire administration and interviewing. Patients were recruited from an HF clinic at a hospital in a Mid-Atlantic city in the US between 2008 and 2009. Inclusion criteria were 1) a confirmed diagnosis of HF, 2) NYHA functional class IIeIV (symptomatic patients), 3) ability to read and write English, 4) no dementia, and 5) age 18 years or older. The diagnosis of HF was confirmed through medical record review using established criteria.31 Patients were carefully questioned by research associates to determine NYHA classification. We included only symptomatic patients because they need to be involved in self-management, including restricted sodium intake and adjustment of diuretics,32,33 and they may need more social support.34 We also included only those patients with no history of dementia identified on medical chart for collaboration during data collection. Written informed consent was obtained from all participants after explanation of the study purpose and procedures.
Fig. 1. Theoretical framework.
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Sample size was calculated using G*Power 3.1.6 based on information from the literature.6,35,36 We assumed that social support was associated with HRQOL mainly through its effects on physical and depressive symptoms. Based on two studies,6,35 given an a of .05, power ¼ .95, 7 predictors, and a total expected R-square ¼ 27% (10% explained by physical symptoms and 17% by depressive symptoms), the estimated sample size was 67.36 Eighty patients were enrolled in the study, but 9 were excluded from the final analyses because 5 did not return the questionnaires, and 4 had missing data. Thus, a total of 71 patients were included in the analyses. Measures Health-related quality of life was defined as patients’ perceptions of the impact of HF on various aspects of their daily life,37 and was assessed using the Minnesota Living with Heart Failure Questionnaire.38,39 This instrument consists of 21 items rated on a scale from 0 (no impact on HRQOL) to 5 (considerable impact on HRQOL). Scores may range from 0 to 105; higher scores indicate poorer HRQOL. Reliability and validity were supported in several studies.38e41 Cronbach’s alpha in the current study was .94. Physical symptoms were defined as common HF-related symptoms and were measured using the Symptom Status Questionnaire-Heart Failure.42 The 7-item instrument assesses 7 common HF symptoms during the past 4 weeks: dyspnea during daytime, dyspnea when lying down, fatigue, chest pain, edema, sleeping difficulty, and dizziness. The items have 4 sub-items: presence (0 is given for no symptom), frequency, severity, and distress. Frequency sub-items have 4 response options, from 1 (less than once per week) to 4 (nearly daily). Severity sub-items have 4 response options, from 1 (slight) to 4 (very much). Distress subitems have 5 response options, from 0 (not at all) to 4 (very much). Possible scores range from 0 to 84, with higher scores indicating more severe physical symptoms. Reliability and validity were supported.42 Cronbach’s alpha in the current study was .92. Depressive symptoms were measured by the Patient Health Questionnaire (PHQ-9),43,44 which consists of 9 items corresponding to the major depressive disorder criteria of the Diagnostic and Statistical Manual of Mental Disorders-IV.43 Items assess the frequency of symptoms over the past 2 weeks using a 4-point Likert scale from 0 (not at all) to 3 (nearly every day). Possible scores range from 0 to 27, with higher scores indicating more severe depressive symptoms.43 Reliability and validity have been supported in patients with HF.45 Cronbach’s alpha was .78 in the current study. Social support was operationalized as marital status, social networks, relationships with health care providers, emotional support, instrumental support, and family relationships. Based on a standard sociodemographic questionnaire, patients were categorized as currently married/cohabitating or not married/ no cohabitating (single, divorced/separated, or widowed). Social networks were defined as the number of significant others who were contacted regularly46 and was also assessed using the standard sociodemographic questionnaire. Patients were asked to list persons whom they contacted regularly, including family, friends, neighbors, religious group members, and club or other group members. Possible scores range from 0 to 25, with higher scores indicating bigger social networks. Relationships with health-care providers were defined as individuals’ perceptions of whether their health-care providers did their best to provide good care and were measured using the Wake Forest Physician Trust Scale.47 This measure consists of 10 items using a 5-point Likert Scale ranging from 1 (strongly disagree) to 5 (strongly agree). Possible total scores range from 10 to 50, with higher scores indicating more trust.47 Reliability and validity were supported.47,48 Cronbach’s alpha in the current study was .84.
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Emotional support was defined as individuals’ perceptions of affective support from family, friends, and important others and was measured using the Multidimensional Scale of Perceived Social Support.49e51 This measure consists of 12 items and uses a 7-point Likert scale ranging from 1 (very strongly disagree) to 7 (very strongly agree). Possible total scores range from 12 to 84, with higher scores indicating greater emotional support. Reliability and validity were supported.51,52 Cronbach’s alpha was .93 in the current study. Instrumental support was defined as tangible support from others and was measured by the Social Support Scale-Instrumental (Heart Failure) developed by the first author. Content validity was supported by two experts in HF research. The measure consists of 5 items on a 5-point Likert Scale ranging from 0 (never) to 4 (always). The 5-items represent 5 types of instrumental support: shopping, preparation of low sodium foods and encouragement to eat low sodium foods, symptom management, monetary support, and readiness to help when instrumental support is needed. Possible total scores range from 0 to 20, with higher scores indicating greater instrumental support. Cronbach’s alpha was .88 in the current study. Family relationships were measured using two subscales of the FES-Family Relationship Index (Cohesion and Conflict).53 Cohesion is defined in the index as the extent of family members’ helpfulness and supportiveness, and conflict as the extent of family members’ expressions of anger and conflicteladen interactions.53 We did not include the Expression subscale in the analysis because of poor reliability in this sample (Cronbach’s alpha ¼ .41). Each subscale has 9 items with dichotomous response options (true or false). Possible total scores for the Cohesion and Conflict subscales range from 4 to 65 and 33 to 80, respectively. Higher scores indicate more cohesive relationships or more conflicted relationships. Reliability and construct validity have been supported.54 The Kuder-Richardson reliability coefficients for the Cohesion and Conflict subscales in the current study were .75 and .74, respectively. Comorbidities,55 age,56 and gender57 were selected as covariates for symptoms. Comorbidities,20 age,20,35 and NYHA functional class58 were selected as covariates for the relationships among social support, symptoms, and HRQOL. Data on covariates and other sociodemographic and clinical characteristics (education, left ventricular ejection fraction, ethnicity, and etiology of HF) were collected using the standard sociodemographic questionnaire and a clinical questionnaire. Data on comorbidities were collected using the Charlson Comorbidity Index, which was included in the clinical questionnaire.59 This index uses the number and seriousness of comorbidities to assess the risk of mortality. The total score is calculated by adding the weighted scores; higher scores indicate more severe comorbidities.59 Data analysis All analyses were done using SPSS (version 21). Bivariate relationships between sociodemographic and clinical characteristics and HRQOL were examined using Pearson’s r for continuous variables and the independent t-test for dichotomous variables. Hierarchical regression analyses were used to determine the types of social support that were significantly related to each of the physical and depressive symptoms, controlling for comorbidities, age, and gender. Hierarchical regression analysis was used to determine the types of social support that were significantly related to HRQOL, controlling for comorbidities, age, and NYHA functional class. A mediated effect implies that the independent variable leads to the mediators, which, in turn leads to the outcome variable (HRQOL).60 General linear regression analysis and simple and hierarchical multiple regression analyses were used to determine whether
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Table 1 Characteristics of the study sample and their bivariate relationships to healthrelated quality of life (N ¼ 71). Characteristics
Mean (SD)
Age (Years) Education (Years) Left ventricular ejection fraction (%) Charlson Comorbidity Index
72 12 39 5
Pearson’s r
Number (%)
t statistics
p value
Gender (male) Marital status (married/co-habitant) Ethnicity (Caucasian) Heart failure etiology (Ischemic) NYHA functional class Class II Class III/IV
47 51 65 44
1.438 2.138 .414 1.458 2.488
.155 .036 .680 .149 .015
.200 .061 .079 .279
(11) (2) (14) (3)
(66) (72) (92) (62)
p value .097 .618 .510 .018
37 (52) 34 (48)
NYHA ¼ New York Heart Association. SD ¼ standard deviation.
physical symptoms and depressive symptoms mediated the relationship between emotional support and HRQOL. The mediator effects were examined because only emotional support was associated with all these three variables in bivariate analyses. Simple and hierarchical multiple regression analyses were used to determine whether physical symptoms mediated the relationship between marital status and HRQOL. This mediator effect was examined because marital status was associated with only physical symptoms and HRQOL in bivariate analyses.
status and emotional support were associated with physical symptoms to similar degrees (bigger coefficients indicate greater effects on the outcome variable). When the covariates of comorbidities, age, and gender were entered into the second block of the model, the significant relationships of marital status and emotional support to physical symptoms remained, and none of the covariates were related to physical symptoms. Social networks, relationships with health care providers, instrumental support, and family relationships were not related to physical symptoms. When all types of social support were entered into the model at the same time, only emotional support was significantly related to depressive symptoms before controlling for comorbidities, age, and gender (R2 ¼ .186, p < .001). Patients who had greater emotional support had less severe depressive symptoms. When the covariates were entered into the second block of the model, the significant relationship of emotional support to depressive symptoms remained, and none of the covariates were related to depressive symptoms. Marital status, social networks, relationships with health care providers, instrumental support, and family relationships were not related to depressive symptoms. When all types of social support were entered into the model at the same time, only marital status was significantly related to HRQOL (R2 ¼ .062, p ¼ .036). Patients who remained in their marital relationship or had a cohabitant had better HRQOL. When covariates were entered into the second block, marital status was still associated with HRQOL. In addition, older age and lower NYHA functional class were associated with better HRQOL.
Results Sample characteristics and their relationships to health-related quality of life The mean age of the 71 patients was 72 years (Table 1). The majority were Caucasians, and they had mild to moderate functional impairment (NYHA functional class II or III). Slightly more than half were males, married or had a cohabitant, and had ischemic HF. Among the sociodemographic and clinical characteristics, marital status, comorbidities, and NYHA functional class were significantly associated with HRQOL in bivariate analyses. Relationships of social support to physical and depressive symptoms and health-related quality of life In the multiple regression analysis, all types of social support were entered into the model at the same time, and only marital status and emotional support were significantly related to physical symptoms (R2 ¼ .292, p < .001) (Table 2). Patients who remained in their marital relationship or had a cohabitant and had greater emotional support had less severe physical symptoms. Marital
Mediating relationships of physical symptoms and depressive symptoms on the relationship between social support and healthrelated quality of life Only emotional support was significantly related to physical symptoms, depressive symptoms, and HRQOL in bivariate analyses. Marital status was associated with physical symptoms and HRQOL, but not depressive symptoms in bivariate analyses. Thus, we explored whether physical symptoms and depressive symptoms mediated the relationship between emotional support and HRQOL, and whether physical symptoms mediated the relationship between marital status and HRQOL. First, we examined the relationship of emotional support to physical symptoms and depressive symptoms. Emotional support was significantly related to both physical symptoms and depressive symptoms in the general linear model analysis (R2 ¼ .568 and 540, respectively, p ¼ .003 and p ¼ .009, respectively, Fig. 2). In the multiple regression analysis, physical symptoms and depressive symptoms were significantly related to HRQOL (R2 ¼ .594, p < .001). Emotional support was significantly related to HRQOL in a simple regression model (R2 ¼ .058, p ¼ .042), but when physical symptoms and depressive
Table 2 Multivariate relationships of social support to physical symptoms, depressive symptoms, and health-related quality of life. Dependent variable
Independent variable
Standardized beta
95% Confidence interval
R2
F
p value
Physical symptoms
Model 1and 2
14.017
<.001
Model 1 and 2 Model 1 Model 2
19.68, .62, .27, 27.44, 29.49, 7.12, 1.20,
.292
Depressive symptoms Health-related quality of life
.39y .30* .43y .25* .30* .31* .36*
.186 .062 .239
15.782 4.572 7.005
<.001 .036 <.001
Marital status Emotional support Emotional support Marital status Marital status Age NYHA functional class
5.88 .11 .09 .95 5.00 29.39 .20
Simple and hierarchical regression. All types of social support (marital status, social networks, relationships with health care providers, emotional support, instrumental support, and family relationships) were entered into Model 1. In Model 2, covariates were entered into the second block of Model 1. Covariates for symptoms were comorbidities, age, and gender. Covariates for health-related quality of life was comorbidities, age, and New York Heart Association functional class. NYHA ¼ New York Heart Association functional class. *p < .05, yp < .001.
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Fig. 2. Mediator effects of Symptoms on the Relationship between Social Support and Health-Related Quality of Life. a ¼ R2 in general linear regression and the rest of the numbers mean standardized beta in simple or multiple regression analyses. b ¼ p value change from in the model of the relationship of social support to health-related quality of life to the model of the relationship of social support and symptoms to health-related quality of life. *p < .05, yp < .001.
symptoms were added to the model, emotional support was no longer significantly related to HRQOL (p ¼ .131), though physical symptoms and depressive symptoms were (R2 ¼ .608, p < .001 for physical symptoms and p ¼ .001 for depressive symptoms). Thus, physical symptoms and depressive symptoms were full mediators of the relationship between emotional support and HRQOL. Similar analyses were done to test the mediating effects of physical symptoms on the relationship between marital status and HRQOL. Marital status was associated with physical symptoms (R2 ¼ .205, p < .001). Physical symptoms were associated with HRQOL (R2 ¼ .538, p < .001). Marital status was associated with HRQOL (R2 ¼ .062, p ¼ .036), but when physical symptoms were added to the model, marital status was no longer significantly related to HRQOL (p ¼ .257), though physical symptoms were (R2 ¼ .547, p < .001). Thus, physical symptoms were a full mediator of the relationship between marital status and HRQOL (Fig. 2). Discussion It has been suggested that social support is important for engaging in self-care to prevent and manage symptoms, reducing depressive symptoms, and maintaining HRQOL in patients with HF.14,18,19,61 However, the relationship between social support and physical symptoms has rarely been examined in patients with HF. In the current study, emotional support was significantly related to physical and depressive symptoms after controlling for covariates, and it was associated with HRQOL through its association with physical and depressive symptoms. Marital status was also associated with physical symptoms and with HRQOL through its association with physical symptoms. These findings can be used to develop interventions to improve physical symptoms in patients with HF. The significant relationship between emotional support and depressive symptoms found in the current study is consistent with prior findings.30,62 For example, in Yu et al’s study,30 among various types of social support, not living with family and poor emotional support were the only variables significantly associated
with depressive symptoms in patients with HF. These findings suggest that improving emotional support may lead to improvement in depressive symptoms. On the other hand, the opposite direction may be possible. For example, patients with depressive symptoms may perceive emotional support differently compared to those patients without depressive symptoms because of distorted cognition.63 This can imply that improvement in both emotional support and depressive symptoms may lead to improvement in HRQOL. The relationship between social support and HRQOL was not supported in several HF studies.21e23,64 Similarly, in the current study, social support was not associated with HRQOL, after controlling for symptoms. The mediating effects of physical and depressive symptoms on the relationship between social support and HRQOL may in part explain this. That is, social support is associated with physical and depressive symptoms and through them with HRQOL. Emotional support for patients with HF may be improved by educating family and important others as well as patients, and by providing them opportunities to participate in group activities. Patients with HF and their families commonly visit clinics together. Clinicians can use these opportunities to educate patients’ families about the importance of their emotional support for patients’ symptoms and HRQOL. In addition, clinicians can teach families basic skills of active listening and expressions of empathy. Patients with HF commonly participate in educational or rehabilitation programs.65 Clinicians can invite patients’ families or important others to join these programs. For example, in some intervention studies,66,67 families or spouses have been invited to participate in the interventions. Structural and functional support were improved after the intervention.66 In educational or rehabilitation programs, clinicians can educate participants about the importance of emotional support for patient outcomes, teach them skills of emotional support, including active listening and appropriate expression of empathy, and give them time to practice the skills. In addition, they can give patients time to share their emotions,
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feelings, and problems with others. Participation in such programs may also give patients opportunities to meet persons who can share emotion, feelings, and issues. Furthermore, clinicians can use the skills of emotional support themselves when they provide care to patients with HF. In addition, clinicians need to search resources of social support to provide more support for those who are single, widowed, and separated. This study had some limitations. The majority of the patients were Caucasian, and social support and its relationships to symptoms and HRQOL may be different in other races. Also in the current study, we measured the size of social networks, but not the quality of social networks. The effects of the quality of social networks on symptoms and HRQOL may differ from the effects of size. There could also be interactions among the variables (e.g., social support and physical and depressive symptoms), but we could not examine all the interactive effects because of the small sample. If there are interactive effects, they could affect the relationships among social support, symptoms, and HRQOL. Despite these limitations, the current study provides important information for developing interventions for patients with HF. The findings suggest that improving emotional support may improve symptoms and, in turn, HRQOL in these patients. Further studies are needed to test interventions to improve emotional support and to determine whether the improvement actually leads to improvement in physical and depressive symptoms and, in turn, HRQOL. Acknowledgment Funding for this study came from an American Nurses Foundation grant to Seongkum Heo. References 1. Juenger J, Schellberg D, Kraemer S, et al. Health related quality of life in patients with congestive heart failure: comparison with other chronic diseases and relation to functional variables. Heart. 2002;87:235e241. 2. Dixon T, Lim LL, Oldridge NB. The MacNew heart disease health-related quality of life instrument: reference data for users. Qual Life Res. 2002;11:173e183. 3. Heo S, Moser DK, Lennie TA, Zambroski CH, Chung ML. A comparison of healthrelated quality of life between older adults with heart failure and healthy older adults. Heart Lung. 2007;36:16e24. 4. Albert N, Trochelman K, Li J, Lin S. Signs and symptoms of heart failure: are you asking the right questions? Am J Crit Care. 2010;19:443e452. 5. Faller H, Stork S, Schuler M, et al. Depression and disease severity as predictors of health-related quality of life in patients with chronic heart failureea structural equation modeling approach. J Card Fail. 2009;15:286e292. e2. 6. De Jong M, Moser DK, Chung ML. Predictors of health status for heart failure patients. Prog Cardiovasc Nurs. 2005;20:155e162. 7. Heo S, Moser DK, Pressler SJ, et al. Dose-dependent relationship of physical and depressive symptoms with health-related quality of life in patients with heart failure. Eur J Cardiovasc Nurs. 2013;12:454e460. 8. Blinderman CD, Homel P, Billings JA, Portenoy RK, Tennstedt SL. Symptom distress and quality of life in patients with advanced congestive heart failure. J Pain Symptom Manage. 2008;35:594e603. 9. Fink AM, Gonzalez RC, Lisowski T, et al. Fatigue, inflammation, and projected mortality in heart failure. J Card Fail. 2012;18:711e716. 10. Bennett JA, Riegel B, Bittner V, Nichols J. Validity and reliability of the NYHA classes for measuring research outcomes in patients with cardiac disease. Heart Lung. 2002;31:262e270. 11. Parissis JT, Nikolaou M, Farmakis D, et al. Clinical and prognostic implications of self-rating depression scales and plasma b-type natriuretic peptide in hospitalised patients with chronic heart failure. Heart. 2008;94:585e589. 12. Ferrans CE, Zerwic JJ, Wilbur JE, Larson JL. Conceptual model of health-related quality of life. J Nurs Scholarsh. 2005;37:336e342. 13. Wu JR, Moser DK, Lennie TA, Burkhart PV. Medication adherence in patients who have heart failure: a review of the literature. Nurs Clin North Am. 2008;43: 133e153. viieviii. 14. Heo S, Lennie TA, Moser DK, Okoli C. Heart failure patients’ perceptions on nutrition and dietary adherence. Eur J Cardiovasc Nurs. 2009;8:323e328. 15. Sayers SL, Riegel B, Pawlowski S, Coyne JC, Samaha FF. Social support and selfcare of patients with heart failure. Ann Behav Med. 2008;35:70e79. 16. Son YJ, Lee Y, Song EK. Adherence to a sodium-restricted diet is associated with lower symptom burden and longer cardiac event-free survival in patients with heart failure. J Clin Nurs. 2011;20:3029e3038.
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Impact of functional support on health-related quality of life in patients with colorectal cancer. Cancer. 2004;101:2737e2743. 29. Simpson SH, Farris KB, Johnson JA, Tsuyuki RT. Using focus groups to identify barriers to drug use in patients with congestive heart failure. Pharmacotherapy. 2000;20:823e829. 30. Yu DS, Lee DT, Woo J, Thompson DR. Correlates of psychological distress in elderly patients with congestive heart failure. J Psychosom Res. 2004;57:573e581. 31. Hunt SA, Abraham WT, Chin MH, et al. 2009 focused update incorporated into the ACC/AHA 2005 guidelines for the diagnosis and management of heart failure in adults a report of the American College of Cardiology Foundation/ American Heart Association Task Force on Practice Guidelines developed in collaboration with the International Society for Heart and Lung Transplantation. J Am Coll Cardiol. 2009;53:e1ee90. 32. Lindenfeld J, Albert NM, Boehmer JP, et al. HFSA 2010 comprehensive heart failure practice guideline. J Card Fail. 2010;16:e1ee194. 33. Yancy CW, Jessup M, Bozkurt B, et al. 2013 ACCF/AHA Guideline for the management of heart failure: a report of the American College of Cardiology Foundation/American heart association Task Force on practice guidelines. Circulation. 2013;128:e240ee319. 34. Blasiole JA, Shinkunas L, Labrecque DR, Arnold RM, Zickmund SL. Mental and physical symptoms associated with lower social support for patients with hepatitis C. World J Gastroenterol. 2006;12:4665e4672. 35. Heo S, Moser DK, Riegel B, Hall LA, Christman N. Testing a published model of health-related quality of life in heart failure. J Card Fail. 2005;11:372e379. 36. Faul F, Erdfelder E, Lang AG, Buchner A. G*power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods. 2007;39:175e191. 37. Scott LD. Caregiving and care receiving among a technologically dependent heart failure population. ANS Adv Nurs Sci. 2000;23:82e97. 38. Rector TS, Cohn JN. Assessment of patient outcome with the Minnesota Living with Heart Failure questionnaire: reliability and validity during a randomized, double-blind, placebo-controlled trial of pimobendan. Pimobendan Multicenter Research Group. Am Heart J. 1992;124:1017e1025. 39. Rector TS, Kubo SH, Cohn JN. Patients’ self-assessment of their congestive heart failure. Part 2: content, reliability and validity of a new measure, the Minnesota Living with Heart Failure questionnaire. Heart Fail; 1987;Oct/Nov:198e209. 40. Bennett SJ, Oldridge NB, Eckert GJ, et al. Discriminant properties of commonly used quality of life measures in heart failure. Qual Life Res. 2002;11:349e359. 41. Heo S, Moser DK, Riegel B, Hall LA, Christman N. Testing the psychometric properties of the Minnesota Living with Heart Failure Questionnaire. Nurs Res. 2005;54:265e272. 42. Heo S, Moser DK, Pressler SJ, Dunbar SB, Mudd-Martin G, Lennie TA. The psychometric properties of the symptom status questionnaire-heart failure. J Cardiovasc Nurs. [Epub ahead of print]. 43. Kroenke K, Spitzer RL, Williams JB. The PHQ-9: Validity of a brief depression severity measure. J Gen Intern Med. 2001;16:606e613. 44. Spitzer RL, Kroenke K, Williams JB. Validation and utility of a self-report version of PRIME-MD: the PHQ primary care study. Primary care evaluation of mental disorders. Patient Health Questionnaire. J Am Med Assoc. 1999;282: 1737e1744. 45. Hammash MH, Hall LA, Lennie TA, et al. Psychometrics of the PHQ-9 as a measure of depressive symptoms in patients with heart failure. Eur J Cardiovasc Nurs. 2013;12:446e453. 46. Bean MK, Gibson D, Flattery M, Duncan A, Hess M. Psychosocial factors, quality of life, and psychological distress: ethnic differences in patients with heart failure. Prog Cardiovasc Nurs. 2009;24:131e140.
S. Heo et al. / Heart & Lung xxx (2014) 1e7 47. Hall MA, Zheng B, Dugan E, et al. Measuring patients’ trust in their primary care providers. Med Care Res Rev. 2002;59:293e318. 48. Balkrishnan R, Dugan E, Camacho FT, Hall MA. Trust and satisfaction with physicians, insurers, and the medical profession. Med Care. 2003;41: 1058e1064. 49. Zimet GD, Dahlem NW, Zimet SG, Farley GK. The multidimensional scale of perceived social support. J Pers Assess. 1988;52:30e41. 50. Dahlem NW, Zimet GD, Walker RR. The multidimensional scale of perceived social support: a confirmation study. J Clin Psychol. 1991;47:756e761. 51. Zimet GD, Powell SS, Farley GK, Werkman S, Berkoff KA. Psychometric characteristics of the multidimensional scale of perceived social support. J Pers Assess. 1990;55:610e617. 52. Canty-Mitchell J, Zimet GD. Psychometric properties of the Multidimensional Scale of Perceived Social Support in urban adolescents. Am J Community Psychol. 2000;28:391e400. 53. Holahan CJ, Moos RH. Life stressors, personal and social resources, and depression: a 4-year structural model. J Abnorm Psychol. 1991;100: 31e38. 54. Hoge RD, Andrews DA, Faulkner P, Robinson D. The family relationship Index: Validity data. J Clin Psychol. 1989;45:897e903. 55. Vaccarino V, Kasl SV, Abramson J, Krumholz HM. Depressive symptoms and risk of functional decline and death in patients with heart failure. J Am Coll Cardiol. 2001;38:199e205. 56. Heo S, Doering LV, Widener J, Moser DK. Predictors and effect of physical symptom status on health-related quality of life in patients with heart failure. Am J Crit Care. 2008;17:124e132. 57. Freedland KE, Rich MW, Skala JA, Carney RM, Davila-Roman VG, Jaffe AS. Prevalence of depression in hospitalized patients with congestive heart failure. Psychosom Med. 2003;65:119e128.
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58. Rector TS, Anand IS, Cohn JN. Relationships between clinical assessments and patients’ perceptions of the effects of heart failure on their quality of life. J Card Fail. 2006;12:87e92. 59. Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis. 1987;40:373e383. 60. Bennett JA. Mediator and moderator variables in nursing research: conceptual and statistical differences. Res Nurs Health. 2000;23:415e420. 61. Chung ML, Moser DK, Lennie TA, Frazier SK. Perceived social support predicted quality of life in patients with heart failure, but the effect is mediated by depressive symptoms. Qual Life Res. 2013;22:1555e1563. 62. Frasure-Smith N, Lesperance F, Gravel G, et al. Social support, depression, and mortality during the first year after myocardial infarction. Circulation. 2000;101:1919e1924. 63. Murrough JW, Iacoviello B, Neumeister A, Charney DS, Iosifescu DV. Cognitive dysfunction in depression: neurocircuitry and new therapeutic strategies. Neurobiol Learn Mem. 2011;96:553e563. 64. Bennett SJ, Baker SL, Huster GA. Quality of life in women with heart failure. Health Care Women Int. 1998;19:217e229. 65. Laederach-Hofmann K, Roher-Gubeli R, Messerli N, Meyer K. Comprehensive rehabilitation in chronic heart failureebetter psycho-emotional status related to quality of life, brain natriuretic peptide concentrations, and clinical severity of disease. Clin Invest Med. 2007;30:E54eE62. 66. Bakan G, Akyol AD. Theory-guided interventions for adaptation to heart failure. J Adv Nurs. 2008;61:596e608. 67. Stromberg A, Martensson J, Fridlund B, Levin LA, Karlsson JE, Dahlstrom U. Nurse-led heart failure clinics improve survival and self-care behaviour in patients with heart failure: results from a prospective, randomised trial. Eur Heart J. 2003;24:1014e1023.
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Types of social support and their relationships to physical and depressive symptoms and health-related quality of life in patients with heart failure Seongkum Heo, PhD, RN a, *, Terry A. Lennie, PhD, RN b, Debra K. Moser, DNSc, RN b, Robert L. Kennedy, PhD c a b c
University of Arkansas for Medical Sciences College of Nursing, 4301 W. Markham Street #529, Little Rock, AR 72205, USA University of Kentucky, Lexington, USA Office of Educational Development, University of Arkansas for Medical Sciences, Little Rock, USA
a r t i c l e i n f o
a b s t r a c t
Article history: Received 31 October 2013 Received in revised form 14 April 2014 Accepted 18 April 2014 Available online xxx
Objectives: To examine the various types of social support associated with physical and depressive symptoms and health-related quality of life (HRQOL) in patients with heart failure (HF) and the mediating effects of symptoms on the relationship between social support and HRQOL. Background: Patients with HF have a high burden of physical and depressive symptoms, along with poor HRQOL. Social support may improve symptoms and HRQOL. Methods: Data on social support (marital status, family relationships, relationships with health care providers, social networks, emotional support, and instrumental support), symptoms, and HRQOL were collected from 71 patients. Hierarchical regression was used to analyze the data. Results: Emotional support was related to all physical and depressive symptoms and HRQOL. Physical and depressive symptoms mediated the relationship between emotional support and HRQOL. Conclusions: Further studies are needed to identify ways to improve emotional support and determine whether the improvement leads to improvements in symptoms and HRQOL. Ó 2014 Elsevier Inc. All rights reserved.
Keywords: Heart failure Social support Emotional support Symptoms Quality of life
Introduction Health-related quality of life (HRQOL) is poorer in patients with heart failure (HF) than in healthy populations and in patients with other chronic diseases.1e3 Heart failure symptoms, including dyspnea and fatigue, and depressive symptoms are prevalent in this population and are strongly associated with poor HRQOL.3e7 Physical symptoms can prevent patients with HF from performing their daily activities that lead to poor HRQOL.8 For instance, many patients with HF have New York Heart Association (NYHA) functional class IIeIV,9 indicating that they experience HF symptoms when they perform daily activities.10 In addition, depressive symptoms also can cause functional impairment that leads to poor HRQOL in this population. For example, depressed patients with HF had reduced daily activities and walking distance compared to non-depressed patients.11 Thus, to improve
Abbreviations: HF, Heart failure; HRQOL, Health-related quality of life; NYHA, New York Heart Association. * Corresponding author. Tel.: þ1 501 686 5375; fax: þ1 501 296-1765. E-mail address: [email protected] (S. Heo). 0147-9563/$ e see front matter Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.hrtlng.2014.04.015
outcomes, it is important to identify modifiable factors affecting symptoms and HRQOL. The revised Wilson and Clearly model suggests that social support may be related to both symptoms and HRQOL.12 Social support may affect physical symptoms through effects on self-care. For instance, social support is associated with adherence to medication treatment and following a low sodium diet,13e15 and lack of adherence to medication treatment and a low sodium diet is associated with more severe symptom burden and higher hospitalization rates.16,17 Heart failure symptoms are important antecedents of hospitalizations in this population.4 Social support has also been associated with depressive symptoms in patients with HF.18 However, the findings on relationships between social support and HRQOL have been inconsistent. Patients with HF have reported that social support was a factor affecting their HRQOL,19 and perceived quality of support has been associated with HRQOL.20 However, the majority of HF studies that have examined the relationships between social support and HRQOL found that these relationships were not significant.21e24 These contradictory findings, in part, may be due to differing effects of different types of social support on HRQOL.
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Social support in HF studies has been conceptualized in many ways, varying from simple structural support (e.g., marital status) to comprehensive combinations of structural and functional support.20e22,25,26 Structural support refers to the existence of a social network and the features of contacts with the network (e.g., marital status and social network).27,28 Martial status refers to a very simple social network with spouse or cohabitant (Fig. 1). Social networks represent a wider range of social networks that extend beyond marital status, including more extended family members, friends, and society. Functional support refers to individuals’ perceptions of the resources that social networks provide (e.g., emotional support, instrumental support, and relationships to health-care providers).27,28 Emotional support refers to intangible support from others except health care providers. Instrumental support refers to tangible support from others. Relationships to health care providers represent support from health care providers. Family relationships may combine structural and functional support because they include not only the existence of a social network but also individuals’ perceptions of the resources that family relationships provide. These different types of structural and functional support may affect symptoms and, in turn, HRQOL differently. The relationships between different types of social support and physical symptoms in patients with HF have been rarely examined. However, a meta-analysis that examined the relationship between different types of support and adherence to medical treatment found that instrumental support had the strongest association with adherence.25 In addition, adherence to medical treatment was greater in patients from cohesive families than in patients from families in conflict.25 In another study,29 patients with HF perceived health care providers as one source of support for medication adherence. Thus, instrumental support, family relationship, and relationships with health care providers may affect self-care, and, in turn, physical symptoms. Relationships between social support and depressive symptoms have been examined in this population. Among different types of structural and functional support, living with families and greater emotional support were the only variables significantly associated with less severe depressive symptoms.30 Finally, relationships between social support and HRQOL have been examined in this population, and the findings were inconsistent. In one study,20 one type of functional support (perceived quality of support), but not another type of functional support (emotional support), was associated with HRQOL. In two other studies,21,22 a combination of different types of structural and functional support was not associated with HRQOL.
One reason for the lack of relationship of social support to HRQOL in HF studies may be that social support affects HRQOL mainly through its effects on other variables, including physical and depressive symptoms.12 If social support is associated with HRQOL indirectly through its effects on physical symptoms and depressive symptoms, this may explain the lack of direct, independent associations between social support and HRQOL in patients with HF.21e23 Thus, examination of direct and indirect associations of social support with HRQOL will provide valuable information on the theoretical framework of HRQOL and the associating factors. Therefore, we examined the relationships of several types of social support (marital status, social networks, relationships with health care providers, emotional support, instrumental support, and family relationships) to physical symptoms (dyspnea, fatigue, chest pain, edema, sleeping difficulty, and dizziness), depressive symptoms, and HRQOL. We also explored the mediating effects of physical and depressive symptoms on the relationship between social support and HRQOL in patients with HF. Methods Design, setting, and sample A cross-sectional correlational design was used to examine the relationships of social support to physical symptoms, depressive symptoms, and HRQOL in a convenience sample of patients with HF. Institutional Review Board approval was obtained for the current study. Eligible patients were referred to research associates by physicians or nurse practitioners in the HF clinic and then approached by the research associates who were trained in questionnaire administration and interviewing. Patients were recruited from an HF clinic at a hospital in a Mid-Atlantic city in the US between 2008 and 2009. Inclusion criteria were 1) a confirmed diagnosis of HF, 2) NYHA functional class IIeIV (symptomatic patients), 3) ability to read and write English, 4) no dementia, and 5) age 18 years or older. The diagnosis of HF was confirmed through medical record review using established criteria.31 Patients were carefully questioned by research associates to determine NYHA classification. We included only symptomatic patients because they need to be involved in self-management, including restricted sodium intake and adjustment of diuretics,32,33 and they may need more social support.34 We also included only those patients with no history of dementia identified on medical chart for collaboration during data collection. Written informed consent was obtained from all participants after explanation of the study purpose and procedures.
Fig. 1. Theoretical framework.
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Sample size was calculated using G*Power 3.1.6 based on information from the literature.6,35,36 We assumed that social support was associated with HRQOL mainly through its effects on physical and depressive symptoms. Based on two studies,6,35 given an a of .05, power ¼ .95, 7 predictors, and a total expected R-square ¼ 27% (10% explained by physical symptoms and 17% by depressive symptoms), the estimated sample size was 67.36 Eighty patients were enrolled in the study, but 9 were excluded from the final analyses because 5 did not return the questionnaires, and 4 had missing data. Thus, a total of 71 patients were included in the analyses. Measures Health-related quality of life was defined as patients’ perceptions of the impact of HF on various aspects of their daily life,37 and was assessed using the Minnesota Living with Heart Failure Questionnaire.38,39 This instrument consists of 21 items rated on a scale from 0 (no impact on HRQOL) to 5 (considerable impact on HRQOL). Scores may range from 0 to 105; higher scores indicate poorer HRQOL. Reliability and validity were supported in several studies.38e41 Cronbach’s alpha in the current study was .94. Physical symptoms were defined as common HF-related symptoms and were measured using the Symptom Status Questionnaire-Heart Failure.42 The 7-item instrument assesses 7 common HF symptoms during the past 4 weeks: dyspnea during daytime, dyspnea when lying down, fatigue, chest pain, edema, sleeping difficulty, and dizziness. The items have 4 sub-items: presence (0 is given for no symptom), frequency, severity, and distress. Frequency sub-items have 4 response options, from 1 (less than once per week) to 4 (nearly daily). Severity sub-items have 4 response options, from 1 (slight) to 4 (very much). Distress subitems have 5 response options, from 0 (not at all) to 4 (very much). Possible scores range from 0 to 84, with higher scores indicating more severe physical symptoms. Reliability and validity were supported.42 Cronbach’s alpha in the current study was .92. Depressive symptoms were measured by the Patient Health Questionnaire (PHQ-9),43,44 which consists of 9 items corresponding to the major depressive disorder criteria of the Diagnostic and Statistical Manual of Mental Disorders-IV.43 Items assess the frequency of symptoms over the past 2 weeks using a 4-point Likert scale from 0 (not at all) to 3 (nearly every day). Possible scores range from 0 to 27, with higher scores indicating more severe depressive symptoms.43 Reliability and validity have been supported in patients with HF.45 Cronbach’s alpha was .78 in the current study. Social support was operationalized as marital status, social networks, relationships with health care providers, emotional support, instrumental support, and family relationships. Based on a standard sociodemographic questionnaire, patients were categorized as currently married/cohabitating or not married/ no cohabitating (single, divorced/separated, or widowed). Social networks were defined as the number of significant others who were contacted regularly46 and was also assessed using the standard sociodemographic questionnaire. Patients were asked to list persons whom they contacted regularly, including family, friends, neighbors, religious group members, and club or other group members. Possible scores range from 0 to 25, with higher scores indicating bigger social networks. Relationships with health-care providers were defined as individuals’ perceptions of whether their health-care providers did their best to provide good care and were measured using the Wake Forest Physician Trust Scale.47 This measure consists of 10 items using a 5-point Likert Scale ranging from 1 (strongly disagree) to 5 (strongly agree). Possible total scores range from 10 to 50, with higher scores indicating more trust.47 Reliability and validity were supported.47,48 Cronbach’s alpha in the current study was .84.
3
Emotional support was defined as individuals’ perceptions of affective support from family, friends, and important others and was measured using the Multidimensional Scale of Perceived Social Support.49e51 This measure consists of 12 items and uses a 7-point Likert scale ranging from 1 (very strongly disagree) to 7 (very strongly agree). Possible total scores range from 12 to 84, with higher scores indicating greater emotional support. Reliability and validity were supported.51,52 Cronbach’s alpha was .93 in the current study. Instrumental support was defined as tangible support from others and was measured by the Social Support Scale-Instrumental (Heart Failure) developed by the first author. Content validity was supported by two experts in HF research. The measure consists of 5 items on a 5-point Likert Scale ranging from 0 (never) to 4 (always). The 5-items represent 5 types of instrumental support: shopping, preparation of low sodium foods and encouragement to eat low sodium foods, symptom management, monetary support, and readiness to help when instrumental support is needed. Possible total scores range from 0 to 20, with higher scores indicating greater instrumental support. Cronbach’s alpha was .88 in the current study. Family relationships were measured using two subscales of the FES-Family Relationship Index (Cohesion and Conflict).53 Cohesion is defined in the index as the extent of family members’ helpfulness and supportiveness, and conflict as the extent of family members’ expressions of anger and conflicteladen interactions.53 We did not include the Expression subscale in the analysis because of poor reliability in this sample (Cronbach’s alpha ¼ .41). Each subscale has 9 items with dichotomous response options (true or false). Possible total scores for the Cohesion and Conflict subscales range from 4 to 65 and 33 to 80, respectively. Higher scores indicate more cohesive relationships or more conflicted relationships. Reliability and construct validity have been supported.54 The Kuder-Richardson reliability coefficients for the Cohesion and Conflict subscales in the current study were .75 and .74, respectively. Comorbidities,55 age,56 and gender57 were selected as covariates for symptoms. Comorbidities,20 age,20,35 and NYHA functional class58 were selected as covariates for the relationships among social support, symptoms, and HRQOL. Data on covariates and other sociodemographic and clinical characteristics (education, left ventricular ejection fraction, ethnicity, and etiology of HF) were collected using the standard sociodemographic questionnaire and a clinical questionnaire. Data on comorbidities were collected using the Charlson Comorbidity Index, which was included in the clinical questionnaire.59 This index uses the number and seriousness of comorbidities to assess the risk of mortality. The total score is calculated by adding the weighted scores; higher scores indicate more severe comorbidities.59 Data analysis All analyses were done using SPSS (version 21). Bivariate relationships between sociodemographic and clinical characteristics and HRQOL were examined using Pearson’s r for continuous variables and the independent t-test for dichotomous variables. Hierarchical regression analyses were used to determine the types of social support that were significantly related to each of the physical and depressive symptoms, controlling for comorbidities, age, and gender. Hierarchical regression analysis was used to determine the types of social support that were significantly related to HRQOL, controlling for comorbidities, age, and NYHA functional class. A mediated effect implies that the independent variable leads to the mediators, which, in turn leads to the outcome variable (HRQOL).60 General linear regression analysis and simple and hierarchical multiple regression analyses were used to determine whether
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Table 1 Characteristics of the study sample and their bivariate relationships to healthrelated quality of life (N ¼ 71). Characteristics
Mean (SD)
Age (Years) Education (Years) Left ventricular ejection fraction (%) Charlson Comorbidity Index
72 12 39 5
Pearson’s r
Number (%)
t statistics
p value
Gender (male) Marital status (married/co-habitant) Ethnicity (Caucasian) Heart failure etiology (Ischemic) NYHA functional class Class II Class III/IV
47 51 65 44
1.438 2.138 .414 1.458 2.488
.155 .036 .680 .149 .015
.200 .061 .079 .279
(11) (2) (14) (3)
(66) (72) (92) (62)
p value .097 .618 .510 .018
37 (52) 34 (48)
NYHA ¼ New York Heart Association. SD ¼ standard deviation.
physical symptoms and depressive symptoms mediated the relationship between emotional support and HRQOL. The mediator effects were examined because only emotional support was associated with all these three variables in bivariate analyses. Simple and hierarchical multiple regression analyses were used to determine whether physical symptoms mediated the relationship between marital status and HRQOL. This mediator effect was examined because marital status was associated with only physical symptoms and HRQOL in bivariate analyses.
status and emotional support were associated with physical symptoms to similar degrees (bigger coefficients indicate greater effects on the outcome variable). When the covariates of comorbidities, age, and gender were entered into the second block of the model, the significant relationships of marital status and emotional support to physical symptoms remained, and none of the covariates were related to physical symptoms. Social networks, relationships with health care providers, instrumental support, and family relationships were not related to physical symptoms. When all types of social support were entered into the model at the same time, only emotional support was significantly related to depressive symptoms before controlling for comorbidities, age, and gender (R2 ¼ .186, p < .001). Patients who had greater emotional support had less severe depressive symptoms. When the covariates were entered into the second block of the model, the significant relationship of emotional support to depressive symptoms remained, and none of the covariates were related to depressive symptoms. Marital status, social networks, relationships with health care providers, instrumental support, and family relationships were not related to depressive symptoms. When all types of social support were entered into the model at the same time, only marital status was significantly related to HRQOL (R2 ¼ .062, p ¼ .036). Patients who remained in their marital relationship or had a cohabitant had better HRQOL. When covariates were entered into the second block, marital status was still associated with HRQOL. In addition, older age and lower NYHA functional class were associated with better HRQOL.
Results Sample characteristics and their relationships to health-related quality of life The mean age of the 71 patients was 72 years (Table 1). The majority were Caucasians, and they had mild to moderate functional impairment (NYHA functional class II or III). Slightly more than half were males, married or had a cohabitant, and had ischemic HF. Among the sociodemographic and clinical characteristics, marital status, comorbidities, and NYHA functional class were significantly associated with HRQOL in bivariate analyses. Relationships of social support to physical and depressive symptoms and health-related quality of life In the multiple regression analysis, all types of social support were entered into the model at the same time, and only marital status and emotional support were significantly related to physical symptoms (R2 ¼ .292, p < .001) (Table 2). Patients who remained in their marital relationship or had a cohabitant and had greater emotional support had less severe physical symptoms. Marital
Mediating relationships of physical symptoms and depressive symptoms on the relationship between social support and healthrelated quality of life Only emotional support was significantly related to physical symptoms, depressive symptoms, and HRQOL in bivariate analyses. Marital status was associated with physical symptoms and HRQOL, but not depressive symptoms in bivariate analyses. Thus, we explored whether physical symptoms and depressive symptoms mediated the relationship between emotional support and HRQOL, and whether physical symptoms mediated the relationship between marital status and HRQOL. First, we examined the relationship of emotional support to physical symptoms and depressive symptoms. Emotional support was significantly related to both physical symptoms and depressive symptoms in the general linear model analysis (R2 ¼ .568 and 540, respectively, p ¼ .003 and p ¼ .009, respectively, Fig. 2). In the multiple regression analysis, physical symptoms and depressive symptoms were significantly related to HRQOL (R2 ¼ .594, p < .001). Emotional support was significantly related to HRQOL in a simple regression model (R2 ¼ .058, p ¼ .042), but when physical symptoms and depressive
Table 2 Multivariate relationships of social support to physical symptoms, depressive symptoms, and health-related quality of life. Dependent variable
Independent variable
Standardized beta
95% Confidence interval
R2
F
p value
Physical symptoms
Model 1and 2
14.017
<.001
Model 1 and 2 Model 1 Model 2
19.68, .62, .27, 27.44, 29.49, 7.12, 1.20,
.292
Depressive symptoms Health-related quality of life
.39y .30* .43y .25* .30* .31* .36*
.186 .062 .239
15.782 4.572 7.005
<.001 .036 <.001
Marital status Emotional support Emotional support Marital status Marital status Age NYHA functional class
5.88 .11 .09 .95 5.00 29.39 .20
Simple and hierarchical regression. All types of social support (marital status, social networks, relationships with health care providers, emotional support, instrumental support, and family relationships) were entered into Model 1. In Model 2, covariates were entered into the second block of Model 1. Covariates for symptoms were comorbidities, age, and gender. Covariates for health-related quality of life was comorbidities, age, and New York Heart Association functional class. NYHA ¼ New York Heart Association functional class. *p < .05, yp < .001.
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Fig. 2. Mediator effects of Symptoms on the Relationship between Social Support and Health-Related Quality of Life. a ¼ R2 in general linear regression and the rest of the numbers mean standardized beta in simple or multiple regression analyses. b ¼ p value change from in the model of the relationship of social support to health-related quality of life to the model of the relationship of social support and symptoms to health-related quality of life. *p < .05, yp < .001.
symptoms were added to the model, emotional support was no longer significantly related to HRQOL (p ¼ .131), though physical symptoms and depressive symptoms were (R2 ¼ .608, p < .001 for physical symptoms and p ¼ .001 for depressive symptoms). Thus, physical symptoms and depressive symptoms were full mediators of the relationship between emotional support and HRQOL. Similar analyses were done to test the mediating effects of physical symptoms on the relationship between marital status and HRQOL. Marital status was associated with physical symptoms (R2 ¼ .205, p < .001). Physical symptoms were associated with HRQOL (R2 ¼ .538, p < .001). Marital status was associated with HRQOL (R2 ¼ .062, p ¼ .036), but when physical symptoms were added to the model, marital status was no longer significantly related to HRQOL (p ¼ .257), though physical symptoms were (R2 ¼ .547, p < .001). Thus, physical symptoms were a full mediator of the relationship between marital status and HRQOL (Fig. 2). Discussion It has been suggested that social support is important for engaging in self-care to prevent and manage symptoms, reducing depressive symptoms, and maintaining HRQOL in patients with HF.14,18,19,61 However, the relationship between social support and physical symptoms has rarely been examined in patients with HF. In the current study, emotional support was significantly related to physical and depressive symptoms after controlling for covariates, and it was associated with HRQOL through its association with physical and depressive symptoms. Marital status was also associated with physical symptoms and with HRQOL through its association with physical symptoms. These findings can be used to develop interventions to improve physical symptoms in patients with HF. The significant relationship between emotional support and depressive symptoms found in the current study is consistent with prior findings.30,62 For example, in Yu et al’s study,30 among various types of social support, not living with family and poor emotional support were the only variables significantly associated
with depressive symptoms in patients with HF. These findings suggest that improving emotional support may lead to improvement in depressive symptoms. On the other hand, the opposite direction may be possible. For example, patients with depressive symptoms may perceive emotional support differently compared to those patients without depressive symptoms because of distorted cognition.63 This can imply that improvement in both emotional support and depressive symptoms may lead to improvement in HRQOL. The relationship between social support and HRQOL was not supported in several HF studies.21e23,64 Similarly, in the current study, social support was not associated with HRQOL, after controlling for symptoms. The mediating effects of physical and depressive symptoms on the relationship between social support and HRQOL may in part explain this. That is, social support is associated with physical and depressive symptoms and through them with HRQOL. Emotional support for patients with HF may be improved by educating family and important others as well as patients, and by providing them opportunities to participate in group activities. Patients with HF and their families commonly visit clinics together. Clinicians can use these opportunities to educate patients’ families about the importance of their emotional support for patients’ symptoms and HRQOL. In addition, clinicians can teach families basic skills of active listening and expressions of empathy. Patients with HF commonly participate in educational or rehabilitation programs.65 Clinicians can invite patients’ families or important others to join these programs. For example, in some intervention studies,66,67 families or spouses have been invited to participate in the interventions. Structural and functional support were improved after the intervention.66 In educational or rehabilitation programs, clinicians can educate participants about the importance of emotional support for patient outcomes, teach them skills of emotional support, including active listening and appropriate expression of empathy, and give them time to practice the skills. In addition, they can give patients time to share their emotions,
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feelings, and problems with others. Participation in such programs may also give patients opportunities to meet persons who can share emotion, feelings, and issues. Furthermore, clinicians can use the skills of emotional support themselves when they provide care to patients with HF. In addition, clinicians need to search resources of social support to provide more support for those who are single, widowed, and separated. This study had some limitations. The majority of the patients were Caucasian, and social support and its relationships to symptoms and HRQOL may be different in other races. Also in the current study, we measured the size of social networks, but not the quality of social networks. The effects of the quality of social networks on symptoms and HRQOL may differ from the effects of size. There could also be interactions among the variables (e.g., social support and physical and depressive symptoms), but we could not examine all the interactive effects because of the small sample. If there are interactive effects, they could affect the relationships among social support, symptoms, and HRQOL. Despite these limitations, the current study provides important information for developing interventions for patients with HF. The findings suggest that improving emotional support may improve symptoms and, in turn, HRQOL in these patients. Further studies are needed to test interventions to improve emotional support and to determine whether the improvement actually leads to improvement in physical and depressive symptoms and, in turn, HRQOL. Acknowledgment Funding for this study came from an American Nurses Foundation grant to Seongkum Heo. References 1. Juenger J, Schellberg D, Kraemer S, et al. Health related quality of life in patients with congestive heart failure: comparison with other chronic diseases and relation to functional variables. Heart. 2002;87:235e241. 2. Dixon T, Lim LL, Oldridge NB. The MacNew heart disease health-related quality of life instrument: reference data for users. Qual Life Res. 2002;11:173e183. 3. Heo S, Moser DK, Lennie TA, Zambroski CH, Chung ML. A comparison of healthrelated quality of life between older adults with heart failure and healthy older adults. Heart Lung. 2007;36:16e24. 4. Albert N, Trochelman K, Li J, Lin S. Signs and symptoms of heart failure: are you asking the right questions? Am J Crit Care. 2010;19:443e452. 5. Faller H, Stork S, Schuler M, et al. Depression and disease severity as predictors of health-related quality of life in patients with chronic heart failureea structural equation modeling approach. J Card Fail. 2009;15:286e292. e2. 6. De Jong M, Moser DK, Chung ML. Predictors of health status for heart failure patients. Prog Cardiovasc Nurs. 2005;20:155e162. 7. Heo S, Moser DK, Pressler SJ, et al. Dose-dependent relationship of physical and depressive symptoms with health-related quality of life in patients with heart failure. Eur J Cardiovasc Nurs. 2013;12:454e460. 8. Blinderman CD, Homel P, Billings JA, Portenoy RK, Tennstedt SL. Symptom distress and quality of life in patients with advanced congestive heart failure. J Pain Symptom Manage. 2008;35:594e603. 9. Fink AM, Gonzalez RC, Lisowski T, et al. Fatigue, inflammation, and projected mortality in heart failure. J Card Fail. 2012;18:711e716. 10. Bennett JA, Riegel B, Bittner V, Nichols J. Validity and reliability of the NYHA classes for measuring research outcomes in patients with cardiac disease. Heart Lung. 2002;31:262e270. 11. Parissis JT, Nikolaou M, Farmakis D, et al. Clinical and prognostic implications of self-rating depression scales and plasma b-type natriuretic peptide in hospitalised patients with chronic heart failure. Heart. 2008;94:585e589. 12. Ferrans CE, Zerwic JJ, Wilbur JE, Larson JL. Conceptual model of health-related quality of life. J Nurs Scholarsh. 2005;37:336e342. 13. Wu JR, Moser DK, Lennie TA, Burkhart PV. Medication adherence in patients who have heart failure: a review of the literature. Nurs Clin North Am. 2008;43: 133e153. viieviii. 14. Heo S, Lennie TA, Moser DK, Okoli C. Heart failure patients’ perceptions on nutrition and dietary adherence. Eur J Cardiovasc Nurs. 2009;8:323e328. 15. Sayers SL, Riegel B, Pawlowski S, Coyne JC, Samaha FF. Social support and selfcare of patients with heart failure. Ann Behav Med. 2008;35:70e79. 16. Son YJ, Lee Y, Song EK. Adherence to a sodium-restricted diet is associated with lower symptom burden and longer cardiac event-free survival in patients with heart failure. J Clin Nurs. 2011;20:3029e3038.
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