Well-being and health in kidney failure: A scoping review

Abstract

Background:

Kidney Failure (KF) is associated with impaired physical function, reduced health-related quality of life (HRQoL), increased healthcare costs, and high rates of cardiovascular complications and mortality. Among individuals with KF, well-being and related constructs, such as positive affect, optimism, self-efficacy, and resilience, may have both mental and physical health benefits, independent of the effects of negative emotions and affective syndromes. However, there has been minimal review of these characteristics in people with KF.

Methods:

We conducted a scoping review, using a semi-systematic approach, to summarize the relationships between well-being characteristics and renal health, the potential mechanisms mediating these relationships, and the effects of interventions that promote positive constructs on adherence and health outcomes. We conducted database searches using PubMed and PsycInfo until November 2020. Articles were included if they examined (1) relationships between a wellbeing construct and health outcome in patients with KF, (2) potential biological or behavioral mediators, or (3) interventions that target positive psychological constructs as outcomes or mediators in KF, and (4) were written in English or Spanish.

Results:

Among patients with KF, well-being constructs are associated with increased health-related quality of life (HRQoL), reduced morbidity and complications, and increased survival. Potential mechanisms mediating these associations include reduced inflammation, improved autonomic and endothelial function, and improved health behavior adherence. Psychological and psychosocial interventions promoting well-being have primarily focused on improving selfefficacy to promote behavior change, with limited study of interventions to promote positive psychological constructs in this population.

Conclusions:

Further research is needed to better understand the relationship between well-being constructs and health, specific to KF populations. This could inform the development of needed interventions that harness the promotion of other positive characteristics to improve well-being and health.

Introduction

Kidney failure (KF), or end-stage renal disease (ESRD), is an irreversible loss of renal function in which the kidneys can no longer meet the body’s needs, necessitating transplant or renal replacement therapy (in which the blood-filtering function of the kidneys is replaced) [1]. It affects nearly 750,000 Americans [2] and is associated with impaired physical function, reduced health-related quality of life (HRQoL), increased healthcare costs, and high rates of cardiovascular complications and mortality [2, 3].

Psychological well-being and constructs associated with emotional wellness (e.g., positive affect, optimism) may be important for health in KF. These constructs are associated with reduced morbidity and mortality in medical populations, oftentimes independent of the effects of negative emotions and disorders, such as depression or anxiety [4]. These relationships may be explained in part by behavioral and biological factors linked to engagement in health behaviors [4, 5], reduced inflammation [6, 7], and improved autonomic function [8-10]. Due to these relationships, interventions to promote psychological well-being are increasingly common [11]. However, to date there has been little synthesis of the well-being literature in patients with KF. Accordingly, we performed a scoping review to examine the links between well-being constructs and health outcomes, biological and behavioral mechanisms mediating these relationships, and interventions that target well-being in individuals with KF.

Methods

In this scoping review, we used a semi-systematic search strategy to identify the most up-to-date evidence on well-being constructs in KF. Scoping reviews are used to synthesize research evidence and map existing literature in a field that has not been comprehensively reviewed . Because they focus on broader topics than a classic systematic review, semi-systematic approaches—in which part of the evidence is reviewed systematically, and gaps are filled using narrative approaches—are often used. We searched PubMed and PsycInfo (the primary databases in both medicine and psychology) for articles published from inception until November 2020. Broad search terms were used to ensure identification of original observational research, clinical trials, systematic reviews, and meta-analyses in our study population. We included a wide array of positive psychological constructs and terms for KF to ensure adequate capture of articles (Table 1). We then used a “snowball” technique to include relevant citations within articles if deemed appropriate for the review.

Table 1.

Search terms

Well-being and related constructs	Kidney Failure terms
well-being, “positive affect”, wellness, “positive psychology”, optimism, gratitude, hope, spirituality, self-efficacy, resilience, “life satisfaction”, satisfaction, “personal growth”, meaning, happiness, happy, joy	kidney failure” or “end stage renal disease” OR “end stage kidney disease” OR “chronic kidney disease” OR KF or ESRD OR CKD OR ESKD OR dialysis OR hemodialysis OR “peritoneal dialysis” or “renal replacement therapy” or RRT

Articles were included if they (1) assessed individuals with KF, (2) examined relationships between a well-being construct and health outcome in patients with KF, (3) assessed potential biological or behavioral mediators, (4) examined interventions that target wellbeing constructs as outcomes or mediators in KF, and (5) were written in English or Spanish. We excluded studies of individuals who had undergone renal transplantation, as the psychological, physiological, and clinical characteristics of these patients differ substantially from those with KF. We posteriorly included articles that described potential mechanisms mediating well-being attributes and health outcomes in other chronic illnesses, when relevant, due to the lack of available evidence specific to KF and the likely generalizability of certain mechanisms.

The search was conducted by lead author (J.Z.). Initial title and abstract screening were completed by two study authors (J.Z. and P.R.). Full text of all potentially eligible articles was obtained and reviewed independently by one of three authors (P.R., R.L., J.Z), and disagreements were resolved through discussion with senior author (C.C.). Data extraction was led by first author and reviewed by the senior author.

Results

Overall, seventeen articles met our inclusion criteria. Most of these were observational, and several focused on interventions to promote well-being-related constructs. There were few studies evaluating potential biological and behavioral mediators between well-being and health that were specific to KF.

Positive Psychological Characteristics and Health Outcomes

Health-related Quality of Life

HRQoL reflects an individual’s perceived physical and mental health [12]. Individuals with KF experience low HRQoL, which is associated with increased rates of hospitalization, complications, cardiovascular events, and mortality [13]. Well-being constructs, such as hope, optimism, resilience, and spiritual well-being, have consistently been associated with improved HRQoL in patients with KF. For example, in a study of 39 individuals receiving hemodialysis, optimism, self-efficacy, fighting spirit, and social support were associated with higher HRQoL, independent of negative constructs [14]. Additionally, hope—an optimistic state of mind, based on expected positive outcomes and belief in one’s capacity to achieve goals [15]—was linked to better adjustment and mental HRQoL in patients receiving dialysis in a prospective study [16]. In the KF population, hope may provide a way for patients to manage intensive treatment regimens and cope with KF’s impact on regular life [16].

Similarly, constructs related to resilience and adaptive coping strategies have been linked to improved HRQoL. In an observational study of 155 outpatients with KF receiving hemodialysis, resilience was strongly associated with higher HRQoL [17]. Specific coping strategies that focus on actively addressing stressors and reframing situations positively have also been linked to improved HRQoL. In another observational study of 78 patients with KF receiving dialysis, positive refocusing (finding positive aspects in difficult life events) and problem orientation (behavioral and mental acts guided toward resolution of a problem) were associated with higher physical HRQoL, while acceptance and positive reappraisal (reviewing a negative event in a positive light) were linked to improved mental HRQoL [18].

Finally, spiritual well-being, defined as “experiencing transcendent meaning and purpose in life” [19], was associated with better mental and physical HRQoL [19] in a cross-sectional study of 95 individuals with KF receiving hemodialysis. Similarly, a transcendent orientation (tendency to rely on faith to solve problems) to stressors was associated with increased physical and mental HRQoL in an observational study of patients with KF receiving dialysis [18].

Morbidity and complications

Though few studies have examined the relationships between positive psychological constructs and health outcomes in individuals with KF, the available data suggests that both optimism and positive affect are associated with health outcomes. Using data from the cross-sectional Hispanic Community Health Study/Study of Latinos (HCHS/SOL), Hernandez et al. examined the relationships between positive affect and cardiovascular health (composite of diet, body mass index [BMI], physical activity, cholesterol, blood pressure, fasting glucose, and smoking status) in 1712 patients with CKD, including patients with KF, and found positive affect to be associated with more favorable cardiovascular health profiles, independent of other factors (β=0.06; 95% CI [0.01, 0.11]) [20]. Furthermore, Morales García, et al., examined the prospective associations between dispositional optimism and hospital admissions in 239 patients on hemodialysis, and found that optimists had a lower risk of hospital admissions than pessimists, regardless of age, gender and comorbidity (OR=0.55; 95% CI [0.32, 0.94]) [21].

Well-being constructs have also been linked to other outcomes relevant to the KF population. Specifically, they have been associated with a reduced risk of cardiovascular disease development, cardiovascular events, and mortality [22]. A recent systematic review (N>14,000) found significant relationships in 65% of analyses between positive constructs and health outcomes in individuals with cardiovascular disease [23]. Finally, similar relationships are seen in patients with type 2 diabetes, a major cause of renal dysfunction, where well-being constructs have been linked to improved glycemic control and reduced rates of complications [5]. These studies highlight the relationships between well-being and a wide range of health outcomes in individuals with, or at risk for, KF.

Survival

Finally, positive psychological constructs are associated with long-term survival and health outcomes in healthy and medically ill populations. Two meta-analyses have found well-being to be associated with reduced mortality (HR=0.98; 95% CI [0.95-1.00]) [22] and optimism to be associated with better physical health (r=0.17; 95% CI [0.15-0.20]) [24], independent of other factors, in general and medical populations.

Though fewer studies have been performed in KF, those that have been performed mirror these findings. For example, in a prospective observational study of 97 individuals with KF, greater life happiness was independently associated with increased survival over a four-year follow-up period [25]. Although further research is warranted, these findings suggest that wellbeing constructs are associated with better outcomes in this patient population.

Potential Mediators

Both behavioral and biological mechanisms may mediate the relationships between positive psychological constructs and medical outcomes in patients with KF (see Figure 1).

Figure 1.

Potential mediating mechanisms between positive psychological constructs and health outcomes

Health behavior adherence

Among individuals with KF, adherence to dialysis and engagement in healthy behaviors is critical. Regular hemodialysis attendance, medication adherence, a healthy diet, and reduced fluid intake are important for maintaining appropriate interdialytic fluid and electrolyte levels [26], and physical activity may reduce cardiovascular risk [27]. Furthermore, engagement in these health behaviors is associated with better quality of life and health outcomes in patients with KF [26].

Self-efficacy, which refers to belief in one’s ability to perform activities to attain a desired outcome, has been consistently linked to health-related intentions and behaviors [28]. In a large review of studies examining dietary adherence in patients with KF, self-efficacy was associated with improved dietary adherence [28]. Additionally, self-efficacy has been linked to increased self-care abilities in patients on hemodialysis [30], as well as medication adherence and physical activity across medical conditions [33, 34].

Resilience has also been linked to treatment adherence. In a prospective study of 123 patients receiving hemodialysis, resilience was significantly associated with treatment adherence [29], and the same characteristic was associated with treatment adherence in a cross-sectional study of 107 dialysis patients [34]. Resilience could be especially helpful in patients with KF, who must adapt to strict diets, complex medication regimens, and frequent medical appointments.

Though the relationships between other psychological constructs and adherence have not been studied specifically in KF populations, these links have been well established in healthy adults and in other patient populations. Dispositional optimism is prospectively associated to a healthier lifestyle, including lower smoking rates, more physical activity, healthier diet, and reduced alcohol intake [4, 35]. Similarly, among individuals with type 2 diabetes, positive constructs, including positive affect, self-esteem, empowerment, and self-efficacy, are associated with improved adherence [5]. Examination of these relationships in individuals with KF will help determine whether these relationships apply this patient population as well.

Inflammation

Sustained systemic and tissue inflammation have been described as two essential components of the uremic milieu seen in KF and are strong predictors of health outcomes in KF. Multiple factors, including oxidative stress, volume overload, immune dysfunction, retention of uremic toxins, and treatment-related factors (e.g., dialysis membranes and central venous catheters) may contribute to inflammation in KF [36]. Increased inflammation may promote insulin resistance and the development of atherosclerosis [37], which can worsen prognosis in patients with KF.

Though studies examining the links between well-being and inflammation in KF have not been performed, well-being constructs have been linked to reduced inflammation in other populations in some, but not all, studies. For example, in a study evaluating acute stress response in individuals with type 2 diabetes, greater daily happiness predicted lower baseline (β=−0.23; 95% CI [−0.22, −0.03]) and post-stress (β=−0.24; 95% CI [−0.25, −0.04]) IL-6 concentrations, after controlling for covariates [6]. An observational study in a healthy population similarly found positive affect to be inversely related to IL-6 levels and cortisol, controlling for other medical conditions and psychological factors [6, 7]. However, other studies have found these relationships to be attenuated when controlling for other medical and psychological factors [38, 39].

Autonomic nervous system function

Autonomic dysfunction, characterized by increased sympathetic activity and reduced parasympathetic activity, is common in KF and is associated with immune system dysregulation, activation of the renin-angiotensin-aldosterone system, and reduced heart rate variability [40]. Though the underlying pathogenesis of autonomic dysfunction in KF is unclear [40], it has significant clinical consequences, including an increased risk of arrhythmias and sudden cardiac death [40].

Well-being constructs have been linked to improved autonomic function in several populations, though they have not been studied in KF. In a cross-sectional study of individuals with suspected coronary artery disease, positive affect was associated with greater high-frequency heart rate variability—a sign of parasympathetic activity—independent of age, gender, medications, coronary artery disease, and relevant health behaviors [8]. Similarly, positive emotions have been associated with resting respiratory sinus arrhythmia, a surrogate for heart rate variability, in healthy adults [9], and dispositional optimism has been linked to lower ambulatory blood pressure [10].

Endothelial dysfunction

Endothelial dysfunction is highly prevalent and has been linked to the progression of renal disease and the development of atherosclerosis and cardiovascular complications [41]. Multiple risk factors, such as hypertension, increased inflammation, oxidative stress, and diabetes-associated factors, are related with endothelial dysfunction and may play a role in the accelerated atherosclerosis observed in patients with CKD and KF [42].

Though not studied in KF, well-being constructs have been linked to improved endothelial function in other populations. In men without cardiovascular disease, dispositional optimism has been associated with lower levels of soluble intercellular adhesion molecule-1 (a marker of endothelial dysfunction), controlling for medical factors, health behaviors, and depression [43]. Optimism and gratitude were also associated with lower levels of markers of endothelial dysfunction, independent of depressive and anxiety symptoms in patients who experienced an acute coronary syndrome [39].

Interventions Targeting Well-being in Kidney Failure

Psychological and psychosocial interventions in KF have increasingly begun to focus on positive psychological constructs. Of the constructs mentioned, programs targeting self-efficacy have been examined most frequently, with some studies also exploring the efficacy of interventions to enhance well-being (see Tables 2 and 3).

Table 2.

Selected interventions targeting positive psychological characteristics

Study author	Type of Study	Participants	Intervention	Outcomes	Main Findings
Interventions Targeting Health Behaviors through Self-efficacy
Tsay (2003) [45]	Randomized controlled trial	62 patients receiving hemodialysis	12-session individualized self-efficacy training program on fluid intake. The program was nurse-based and administered during dialysis sessions; aimed to improve patients’ achievements and experiences through praise, encouragement and targeted emotional regulation.	Interdialytic weight gain	Interdialytic weight gain decreased significantly more (0.65 kg over 6 months) in intervention but not control group (0.17kg) (p=0.006).
Interventions Targeting Self-efficacy, Quality of Life and other Outcomes
Lii et al. (2007) [46]	Randomized controlled trial	48 patients receiving hemodialysis	8, 2-hour session group CBT-based psychosocial, education intervention targeting depression, self-efficacy and quality of life. Targeted disease burden, negative perceptions, maladaptive behaviors, and motivation. Psychologist and clinical nurse led.	Self-care self-efficacy (SUPPH), Depression (BDI), QoL (Short Form-36)	Self-care self-efficacy (MD:16, p=0.001), depression (MD:−3.05, p=0.001), and quality of life physical (MD:2.55, p=0.008), but not mental (MD:3.52, p=0.190), significantly improved for patients in the therapy group when compared to control group.
Moattari et al., (2012) [47]	Randomized controlled trial	48 patients receiving hemodialysis	6-week empowerment intervention targeting self-efficacy, QoL, and medical outcomes. It consisted of 6 individual and 2 group counselling sessions. Individual sessions focused on self-awareness, goal setting, and problem solving tailored to participant’s needs. Group sessions focused on stress management, problem-focused and emotion-focused coping strategies, social support, and motivation.	Self-care self-efficacy (SUPPH), QoL, interdialytic weight gain, blood pressure, other biomarkers.	Intervention group had significant improvement in overall self-efficacy scores (MD:−12.02 [−18.41, −5.53]; p<0.001), stress reduction (MD:−3.6 [−4.4, −1.57]; p<0.002), and quality of life (MD:−2.93 [−4.39, −1.47]; p<0.001), when compared to control group. Intervention group also had significantly better systolic/diastolic blood pressures (p<0,001), interdialytic weight gain (p<0.003), hemoglobin (p<0.005) and hematocrit levels (p<0.004).
Positive psychology intervention
Hernandez et al. (2018) [50]	Pilot single arm trial	14 patients with elevated depressive symptoms and receiving hemodialysis	5-week Internet-based positive psychology intervention. The intervention aimed to increase positive emotional experiences by targeting constructs such as optimism, gratitude, mindfulness, and resilience through structured activities.	Feasibility. Secondary outcome of depression (Center for Epidemiological Studies Depression Scale)	There was 85.7% retention rate. Significant improvements were evident for depressive symptoms (15.3 vs. 10.9; p=0.04)

BAI Beck Anxiety Inventory; BDI Beck Depression Inventory; CBT Cognitive Behavioral Therapy; MD Mean Difference; QoL Quality of Life; SUPPH Strategies Used by People to Promote Health

Table 3.

Elements, examples, and strategies of existing interventions to enhance well-being

Positive Psychology exercises [48-50]
Gratitude-based activities	Individuals may be asked to recall and write about recent positive events, write a letter of gratitude to someone, or share a positive event with a friend or family member.
Strength-based activities	Individuals may be asked to recall a time when they were successful or to use a strength that is very important to them.
Meaning-based activities	Individuals may complete an enjoyable or meaningful activity, perform a kind act for another person, or identify important things in their lives.
Self-efficacy and Empowerment [45, 47]
CBT-based empowerment	Individuals are encouraged to manage their illness through a series of techniques, including education about the illness and self-care behaviors, creation of a behavior change plan, goal-setting, problem-solving of barriers, and tailored support. Individuals are then asked to reflect on emotions elicited by empowerment.
Self-efficacy	Individuals work to improve emotions around achievements and experiences through praise and encouragement, decreasing emotional and physical arousal.
Coping strategies [18, 46]
CBT-based coping, purposes-and-practice pattern	Individuals work to restructure negative thought patterns, problem solve barriers to adherence, and develop positive beliefs and self-care strategies.
Positive refocusing	Individuals are asked to identify positive aspects of difficult life events.

Self-efficacy

Self-efficacy may play a major role in patients’ motivation to adhere to health behaviors. Because patients with greater self-efficacy may be more confident in their ability to manage their complex medical regimens and lifestyle choices, it is a promising target for interventions designed for individuals with KF [44]. Many recently developed health behavior interventions utilize multiple components to promote adherence and self-efficacy. These interventions include psychosocial modules such as group therapy sessions, emotional regulation training, and problem-solving of barriers to target self-efficacy (see Table 2).

A small number of trials have studied psychosocial interventions targeting self-efficacy to improve adherence, quality of life, and other outcomes. In one randomized trial, a self-efficacy individualized training program targeting fluid intake in patients on hemodialysis led to less interdialytic weight gain compared to usual care (n=62) [45], though groups had different levels of weight gain at baseline. In a second randomized trial of 48 patients receiving hemodialysis, a cognitive behavioral therapy-based group psychosocial intervention targeting depression, self-care self-efficacy, and quality of life led to greater improvements in all three outcomes compared to enhanced usual care [46]. Finally, a randomized, controlled trial of a 6-week, individual and group empowerment intervention focused on self-awareness, motivational goal setting, problem solving, and coping strategies led to significant improvements in self-efficacy, stress, quality of life, and some medical outcomes (e.g., interdialytic weight gain, blood pressure) in 48 patients receiving hemodialysis [47].

Positive psychology interventions

Positive psychology (PP) interventions utilize structured activities (e.g., expressing gratitude) to cultivate well-being and related psychological constructs [48]. In trials of (mostly healthy) individuals, these interventions have been linked to consistent improvements in well-being and reductions in depressive symptoms [11]. PP has also been explored in medical populations, where it similarly increases positive psychological constructs and, in some cases, improves adherence to health behaviors, especially when combined with other behavioral approaches [49]. To date, only one study has examined the efficacy of a positive psychology intervention in patients with KF. In a single-arm, proof-of-concept trial of an internet-based PP intervention, hemodialysis patients with depressive symptoms completed web modules promoting skills for increasing positive emotion. It was feasible (86% participant retention), well-accepted, and associated with significant pre-post reductions in depressive symptoms [50].

Areas for Further Research:

These findings highlight several areas for further research. First, prospective observational studies with extended follow-up may help to clarify the relationships between well-being characteristics and KF-specific outcomes. To better delineate the relationships between well-being constructs and biological markers of health, additional studies with large sample sizes, prospective designs, and careful control for potential confounding factors are needed, as existing studies are small and have yielded mixed results. Third, while evidence suggests that interventions targeting self-efficacy may be effective at improving health behavior adherence, additional work may confirm these findings in larger long-term trials, assess the impact of these interventions on medical outcomes, and identify characteristics and treatment modalities that lead to the greatest benefits. Fourth, research is needed to explore interventions targeting other positive psychological characteristics, such as optimism, gratitude, and resilience, in KF patients, as they have been consistently associated with improved outcomes in other medically ill populations. Finally, research in all these areas would benefit from the inclusion of individuals with chronic kidney disease who do not require dialysis or who have undergone renal transplantation.

Limitations and Conclusions

This review has several limitations. To provide a broad overview of the literature involving well-being constructs and health in KF, we performed a scoping review; as a result, not all articles were included. Additionally, due to substantial heterogeneity in research designs, outcome measures, and psychological constructs examined, we did not conduct quantitative analyses of the links between psychological constructs and health outcomes. Furthermore, the cross-sectional design of the studies outlining mechanisms also limits the ability to infer causality. Finally, we included relevant articles in other patient populations when research in KF was not available. Though we aimed to include only studies from those populations most relevant to KF (e.g., type 2 diabetes, cardiovascular disease), the findings from these studies may not generalize fully to the KF population.

Despite these limitations, several important conclusions can be drawn from the literature. First, well-being characteristics appear to be associated with improved health, including increased HRQoL, reduced morbidity and complications, and increased survival, in patients with KF, consistent with studies in other medical populations. Second, these associations may be mediated by both behavioral and biological mechanisms, including inflammation, autonomic nervous system dysfunction, and endothelial dysfunction. Finally, though there has been some research into the development of self-efficacy interventions in KF, there has been limited study of interventions to promote other well-being constructs in this population. Additional research in these areas may help us better understand the relationships between positive psychological constructs and health in KF and may inform the development of interventions that have the potential to promote well-being and health in this high-risk population.