Self-care self-efficacy, depression, and quality of life among patients receiving hemodialysis in Taiwan

Abstract

The purpose of this study is to examine relationships among self-care self-efficacy, depression, and quality of life in 160 patients receiving hemodialysis. The study is a descriptive, correlational design. Measures include Strategies Used by People to Promote Health, the Geriatric Depression Scale, and the Quality of Life Index.

Results indicate that self-care self-efficacy and depression are the significant predictors of quality of life after controlling for the effect of age. Self-care self-efficacy explains 47.5% of the variance (β=0.52, p<0.001) and depression (β=−0.29, p<0.001) explains an additional 5.5% of variance in quality of life. The study provides important information for health care providers as they design interventions for patients receiving hemodialysis.

Introduction

End Stage Renal Disease (ESRD) is a chronic illness. Treatment modalities for the disease often involve either long-term dialysis or kidney transplantation. In Taiwan, availability of the organ is a major issue, and 95% of ESRD patients are currently receiving hemodialysis as treatment (Renal Club, 1999). Patients with ESRD undergo a complex treatment regime. This involves not only dialysis but also a wide range of multiple and radical lifestyle changes that affect the individual's social and psychological functioning. As treatment is a long-term process, patients have to use strategies to manage their illness. According to Lev and Owen (1998), patients who have a sense of confidence in their ability to perform self-care behaviors are more likely to actually perform these tasks. Thus, individuals with high levels of self-care self-efficacy are better able to manage their ESRD. The effect of emotional distress of the illness on the person may be decreased, and his/her quality of life may be improved.

Bandura's self-efficacy theory provided the framework for this study (Bandura, 1997). Self-efficacy theory is based on the premise that the individual makes judgments about his/her capacity to engage in self-care behaviors to produce desired outcomes. This judgment, or self-efficacy, provides a bridge between knowledge and actual self-care behaviors. The theory is valid for behaviors of patients receiving dialysis because there is a strong consensus that knowing what one should do for their disease does not necessarily mean that self-care behaviors will follow. Thus, it is reasonable to hypothesize that patients with ESRD would be more likely to engage in self-care behaviors if they have more confidence in their ability to carry out these behaviors.

There is accumulating evidence that efficacy expectations exert a causal influence on behavior (Bandura, 1997). Within the theory, self-care self-efficacy is defined as a person's confidence in being able to perform relevant self-care behaviors in a particular situation (Lev and Owen, 1996). Efficacy expectation refers to a person's perception that he or she is capable of performing a self-care behavior successfully to produce a certain outcome. Lev and Owen (1996) found a positive relationship between self-care self-efficacy and quality of life and a negative correlation between self-care self-efficacy and negative moods in 97 hemodialysis patients.

Increased self-efficacy is associated with increased adherence to treatment, behaviors perceived as promoting health, and decreased physical and psychological symptoms (Cummings et al., 1982; Given and Given, 1989; Lev, 1997). People who are confident of their abilities engage in activities that promote health. A patient's inability to adjust to illness may lead to negative outcomes such as treatment non-compliance and decreased quality of life (Meichenbaum and Turk, 1987).

Studies of the patient's adjustment to chronic illness have often focused on the understanding of physical and psychological variables, which influence health outcomes. Although self-efficacy expectations account for a major portion of outcomes in illness (Bandura, 1997), little research has addressed the self-care self-efficacy in patients receiving hemodialysis. Furthermore, improved quality of life has been proposed as a major outcome in chronic illness (Callahan, 1990). However, previous studies with patients with ESRD have revealed separate bivariate relationships either between perceived self-care self-efficacy and quality of life or between depression and quality of life, (Lev and Owen, 1998; Killingworth and Akker, 1996; Steele et al., 1996); no research has simultaneously examined the relationships among all three domains. Inclusion of perceived self-care self-efficacy, depression and quality of life in a testing model would extend knowledge and inform health care providers about specific risk factors for the outcome of quality of life in ESRD patients. The purpose of this study was to test the relationships of self-efficacy, depression, and quality of life in patients receiving hemodialysis.

Many studies have investigated quality of life as the outcome of treatment in end-stage renal disease, and there is a vast amount of literature debating the definition and measurement of quality of life. However, there is a growing consensus that the domains of quality of life should include the areas of physical, psychological, social functioning and general satisfaction with life (Wade, 1992). Studies documented that patients receiving dialysis treatment had a lower quality of life than people in the general population (Evans et al., 1985; Gudex, 1995; Lindqvist and Sjoden, 1998; Lok, 1996). Furthermore, a Taiwanese study, which used the Quality of Life Index, showed that the quality of life in patients undergoing hemodialysis is lower than that of those with renal transplant, breast cancer, colon cancer and leukemia (Chen and Ku, 1998). Uncertainty about the future and lack of energy emerged as the major contributors to poor quality of life (Gudex, 1995).

Evans et al. (1985) assessed the quality of life of 859 patients undergoing dialysis or following transplantation, and found that only 47.5% of the former were able to function at nearly normal levels, as compared to 79.1% of the latter. Only 24.7% of patients receiving dialysis were able to work, as compared to 75% of the transplant recipients. Furthermore, those patients treated by hemodialysis had lower levels of life satisfaction and well-being, and higher levels of emotional distress than transplant recipients.

When the relationships between quality of life and emotional distress in patients with ESRD were explored, research revealed that quality of life was significantly negatively correlated with depression and anxiety (Killingworth and Akker, 1996; Steele et al., 1996). Similarly, Mapes (1991) found that psychological distress explained 21% of the variance in quality of life in the dialysis population.

Depression is a common psychological response in chronic illness. Research has shown widely varying rates of depression (ranging from 30% to 100%) in dialysis patients (Levenson and Glocheski, 1991). This discrepancy may result from differences in definitions and measures used for depression (Levenson and Glocheski, 1991). For example, Smith et al. (1985), using the Beck Depression Inventory, found that 47% of dialysis patients were depressed. The figures were 10% when the Multiple Affect Adjective Checklist was used, and 5% when DSM-III criteria were used. In other studies, approximately 50% of the respondents indicated borderline or clinically significant signs of anxiety and depression (Gudex, 1995; Killingworth and Akker, 1996). Yet a Taiwan study, using the Beck Depression Inventory, found only mild depression in a convenience sample of 110 hemodialysis patients (Chiang and Chung, 1997). Therefore, a comparison of these studies is meaningless.

Depression measures often include somatic symptoms that may be confused with symptoms commonly observed in patients with ESRD. Barrett, Vavasour and Major (1990) found that somatic symptoms are strongly associated with depression in dialysis patients. Uremia itself produces irritability, decreased appetite, insomnia, fatigue, and poor concentration. Furthermore, these patients may have other conditions that influence mood, including anemia, electrolyte imbalance, and underlying diseases. Disease severity or dialysis duration may also affect the mood state. Few studies have addressed these confounding variables.

In summary, ESRD has a great impact on patients, who require major lifestyle changes and must use strategies to manage their chronic illness. A person with an increased perception of self-care self-efficacy is more likely to participate in self-care activities. It is reasonable to assume that self-care self-efficacy and depression contribute to quality of life in dialysis patients. In this way, psychological distress could be decreased and quality of life improved.

Based on the literature review, the following hypotheses or research questions were proposed and examined in this study: (a) Is self-care self-efficacy and depression related to quality of life in hemodialysis patients? and (b) Could self-care self-efficacy and depression explain a significant amount of variance controlling for demographic and disease related variables in dialysis patients?