An integrative review of the methodology and findings regarding dietary adherence in end stage kidney disease

Impact of Dietary Potassium Restrictions in CKD on Clinical Outcomes: Benefits of a Plant-Based Diet

In patients with advanced-stage chronic kidney disease (CKD), progressive kidney function decline leads to increased risk for hyperkalemia (serum potassium > 5.0 or >5.5 mEq/L). Medications such as renin-angiotensin-aldosterone system inhibitors pose an additional hyperkalemia risk, especially in patients with CKD. When hyperkalemia develops, clinicians often recommend a diet that is lower in potassium content. This review discusses the barriers to adherence to a low-potassium diet and the impact of dietary restrictions on adverse clinical outcomes. Accumulating evidence indicates that a diet that incorporates potassium-rich foods has multiple health benefits, which may also be attributable to the other vitamin, mineral, and fiber content of potassium-rich foods. These benefits include blood pressure reductions and reduced risks for cardiovascular disease and stroke. High-potassium foods may also prevent CKD progression and reduce mortality risk in patients with CKD. Adjunctive treatment with the newer potassium-binding agents, patiromer and sodium zirconium cyclosilicate, may allow for optimal renin-angiotensin-aldosterone system inhibitor therapy in patients with CKD and hyperkalemia, potentially making it possible for patients with CKD and hyperkalemia to liberalize their diet. This may allow them the health benefits of a high-potassium diet without the increased risk for hyperkalemia, although further studies are needed.

Limitations of Existing Dialysis Diet Apps in Promoting User Engagement and Patient Self-Management: Quantitative Content Analysis Study

Background

With the unprecedented growth of mobile technology, a plethora of dialysis diet apps have been developed to promote patient dietary self-management. Nevertheless, the utility of such apps remains questionable.

Objective

This study aimed to evaluate the content, features, and quality of commercial dialysis diet apps for adult dialysis patients.

Methods

This study consisted of a quantitative content analysis of commercial dialysis diet apps downloaded from Google Play and the Apple App Store available in the Asian marketplace, searched for using the following keywords in English: dialysis diet and diet for kidney disease. Free and paid apps available in English that provide nutrition information for adult dialysis patients were included. Apps that were not relevant to the dialysis diet, not meant for patient self-management, or redundant were excluded. Apps were evaluated for language medium (subscore=1), credibility (subscore=1), food database (subscore=1), valuable features (subscore=12), health-behavior theory constructs (subscore=60), and technical quality (subscore=25). The relationships among the variables of interest were determined by Pearson correlation. Stepwise multiple linear regression analysis was performed to identify the features that contribute to greater technical quality of dialysis diet apps. Statistical significance was defined as P<.05.

Results

A total of 22 out of 253 apps (8.7%) were eligible for evaluation. Based on a 100-point scale, the mean overall score of the apps was 31.30 (SD 14.28). Only 5% (1/22) of the apps offered relevant language options, and 46% (10/22) contained food databases. In addition, 54% (12/22) of the apps were not credible. The mean score for valuable features was 3.45 (SD 1.63) out of 12, in which general education (16/22, 73%), free download (15/22, 68%), and usability (13/22, 59%) were the three most popular features. However, the apps scored a mean of 13.41 (SD 11.56) out of 60 for health-behavior theory constructs. The overall app technical quality was considered poor, with a mean score of 2.70 (SD 0.41) out of 5. The scores of valuable features (r=.65, P=.001) and health-behavior theory constructs (r=.55, P=.009) were positively correlated with the overall technical quality of the commercial dialysis diet apps. Features such as free download (β=.43, P=.03) and usability (β=.41, P=.03) could significantly determine the functional quality of the apps. Health-behavior theory constructs such as self-monitoring could significantly predict both the subjective quality (β=.55, P=.008) and the engagement quality (β=.66, P=.001) of the apps, whereas the information quality domain could be determined by plan or orders (β=.48, P=.007) and knowledge (β=.45, P=.01).

Conclusions

Although most of the available commercial dialysis diet apps are free and easy to use, they are subject to theory deficiency, limited language options, and a lack of food databases, credibility, tailored education, and overall technical quality.

Diet in Chronic Kidney Disease: an integrated approach to nutritional therapy

A healthy diet is an essential requirement to promote and preserve health, even in the presence of diseases, such as chronic kidney disease (CKD). In this review, nutritional therapy for CKD will be addressed considering not only the main nutrients such as protein, phosphorus, potassium, and sodium, which require adjustments as a result of changes that accompany the reduction of renal functions, but also the benefits of adopting dietary patterns associated with better outcomes for both preventing and treating CKD. We will also emphasize that these aspects should also be combined with a process of giving new meaning to a healthy diet so that it can be promoted. Finally, we will present the perspective of an integrated approach to the individual with CKD, exploring the importance of considering biological, psychological, social, cultural, and economic aspects. This approach has the potential to contribute to better adherence to treatment, thus improving the patient's quality of life.

Is Health Literacy of Dialyzed Patients Related to Their Adherence to Dietary and Fluid Intake Recommendations?

Non-adherence to dietary and fluid intake recommendations (NADFIR) is an important factor for the effective treatment of dialyzed patients and may be hindered by low health literacy (HL). Therefore, we assessed whether low HL of dialyzed patients is associated with their NADFIR. We performed a multicentric cross-sectional study in 20 dialysis clinics in Slovakia (n = 452; response rate: 70.1%; mean age = 63.6 years; males: 60.7%). We assessed the association between nine domains of HL and non-adherence (high serum potassium, high serum phosphate, relative overhydration, and self-reported NADFIR) using general linear models adjusted for age and gender. Moreover, we assessed the moderation by socioeconomic status (SES). We found higher NADFIR among patients with less sufficient information for health management (high serum phosphate level; odds ratio (OR): 0.77; 95% confidence interval (CI): 0.63-0.94), with a lower ability to actively manage their health (self-reported diet non-adherence; OR: 0.74; 95% CI: 0.62-0.89), and those less able to actively engage with healthcare providers (overhydrated; OR: 0.78; 95% CI: 0.65-0.94). Moreover, SES modified this relation. Low HL affects the adherence of dialyzed patients. This shows a need to support patients with low HL and to train healthcare providers to work with these patients, taking into account their SES.

Barriers and Facilitators of Fruit and Vegetable Consumption in Renal Transplant Recipients, Family Members and Healthcare Professionals-A Focus Group Study

Low fruit and vegetable consumption is associated with poor outcomes after renal transplantation. Insufficient fruit and vegetable consumption is reported in the majority of renal transplant recipients (RTR). The aim of this study was to identify barriers and facilitators of fruit and vegetable consumption after renal transplantation and explore if certain barriers and facilitators were transplant-related. After purposive sampling, RTR (n = 19), their family members (n = 15) and healthcare professionals (n = 5) from a Dutch transplant center participated in seven focus group discussions (three each for RTR and family members, one with healthcare professionals). Transcripts were analyzed using social cognitive theory as conceptual framework and content analysis was used for identification of themes. Transplant-related barriers and facilitators were described separately. In categorizing barriers and facilitators, four transplant-related themes were identified: transition in diet (accompanied by, e.g., fear or difficulties with new routine), physical health (e.g., recovery of uremic symptoms), medication (e.g., cravings by prednisolone) and competing priorities after transplantation (e.g., social participation activities). Among the generic personal and environmental barriers and facilitators, food literacy and social support were most relevant. In conclusion, transplant-related and generic barriers and facilitators were identified for fruit and vegetable consumption in RTR. The barriers that accompany the dietary transition after renal transplantation may contribute to the generally poorer fruit and vegetable consumption of RTR. These findings can be used for the development of additional nutritional counseling strategies in renal transplant care.

The relationship of volume overload and its control to hypertension in hemodialysis patients

Hypertension is highly prevalent and associated with poor clinical outcomes among individuals receiving maintenance hemodialysis (HD). Volume overload is a key modifiable contributor to hypertension and cardiovascular disease in the HD population. Despite their importance, assessment and treatment of volume overload and hypertension remain major clinical challenges and have substantial implications for both clinical outcomes and patient experiences of care. This review will summarize current data on the diagnosis, epidemiology, pathophysiology, and clinical consequences of hypertension and volume overload in HD patients. We will also identify priorities for future research studies.

Factors associated with adherence to dietary prescription among adult patients with chronic kidney disease on hemodialysis in national referral hospitals in Kenya: a mixed-methods survey

Introduction

Adherence to dietary prescriptions among patients with chronic kidney disease is known to prevent deterioration of kidney functions and slow down the risk for morbidity and mortality. This study determined factors associated with adherence to dietary prescription among adult patients with chronic kidney disease on hemodialysis.

Methods

A mixed-methods study, using parallel mixed design, was conducted at the renal clinics and dialysis units at the national teaching and referral hospitals in Kenya from September 2018 to January 2019. The study followed a QUAN + qual paradigm, with quantitative survey as the primary method. Adult patients with chronic kidney disease on hemodialysis without kidney transplant were purposively sampled for the quantitative survey. A sub-sample of adult patients and their caregivers were purposively sampled for the qualitative survey. Numeric data were collected using a structured, self-reported questionnaire using Open Data Kit “Collect software” while qualitative data were collected using in-depth interview guides and voice recording. Analysis on STATA software for quantitative and NVIV0 12 for qualitative data was conducted. The dependent variable, “adherence to diet prescription” was analyzed as a binary variable. P values < 0.1 and < 0.05 were considered as statistically significant in univariate and multivariate logistic regression models respectively. Qualitative data were thematically analyzed.

Results

Only 36.3% of the study population adhered to their dietary prescriptions. Factors that were independently associated with adherence to diet prescriptions were “flexibility in the diets” (AOR 2.65, 95% CI 1.11–6.30, P 0.028), “difficulties in following diet recommendations” (AOR 0.24, 95% CI 0.13–0.46, P < 001), and “adherence to limiting fluid intake” (AOR 9.74, 95% CI 4.90–19.38, P < 0.001).

Conclusions

For patients with chronic kidney disease on hemodialysis, diet prescriptions with less restrictions and requiring minimal extra efforts and resources are more likely to be adhered to than the restrictive ones. Patients who adhere to their fluid intake restrictions easily follow their diet prescriptions. Prescribed diets should be based on the individual patient’s usual dietary habits and assessed levels of challenges in using such diets. Additionally, diet adherence messages should be integrated with fluid limitation messages. Further research on understanding patients’ adherence to fluid restriction is also suggested.

The association between dietetic consultation and time to dialysis for patients attending a pre-dialysis clinic: A retrospective cohort study

AIM

A multidisciplinary approach, including dietetics, is considered the optimal model of care for dialysis preparation. Dietetic consultation (DC) focuses on symptom management and dietary changes to delay time to dialysis. Evidence of the effectiveness of DC on time to dialysis is limited. This study aimed to investigate the impact of DC on time to dialysis for patients attending a pre-dialysis clinic.

METHODS

A retrospective cohort study was designed to include all patients attending outpatient pre-dialysis clinics at a large metropolitan renal service between January 2014 and March 2018. Time to dialysis (days) was compared between patients that received DC and those who did not. Cox proportional hazards analysis allowing for adjustment of differences and confounders was undertaken.

RESULTS

A cohort of 246 patients was identified. Median estimated glomerular filtration rate was 16mL/min per 1.73 m² (interquartile range = 13-20) at initial pre-dialysis clinic visit and 63% commenced dialysis during the study period. Only 41% of patients received dietetic consultation. Significantly fewer patients needed to commence dialysis in the DC group compared to the no-DC group (hazards ratio 0.63; 95% confidence interval (CI) 0.45-0.89; P = 0.008 Cox proportion hazard). The DC group commenced dialysis significantly later than the no-DC group; 933 days (95% CI 832-1034) versus 710 days (95% CI 630-790) respectively, after the initial pre-dialysis clinic visit; log-rank 0.005.

CONCLUSION

DC provided to patients attending a pre-dialysis clinic was associated with a delayed time to dialysis. Standardised referral pathways to improve patient access to renal dietetic services are recommended to optimise care.

Prediction of Nonadherence and Renal Prognosis by Pre-Transplantation Serum Phosphate Levels

Background

Identifying characteristics of patients at high risk of poor adherence before transplantation would be advantageous. However, the optimal approach for characterizing such patients remains unknown. We aimed to evaluate the association between factors for hemodialysis nonadherence and post-transplant renal prognosis. We hypothesized that these factors would influence post-transplantation adherence and worsen renal prognosis.

Material/Methods

We reviewed patients on hemodialysis who underwent kidney transplantation at our hospital between 2000 and 2017 to identify risk factors associated with poor prognosis. The patients’ background and pre-transplantation data, known hemodialysis nonadherence factors, serum phosphate and potassium levels, and interdialytic weight gains were evaluated. The primary endpoint was renal death. We also evaluated the fluctuation of calcineurin inhibitor concentration and weight gain after transplantation.

Results

Seventy-seven patients were eligible, and the mean observational period was 83.2 months (standard deviation, 50.5). Thirteen patients reached the endpoint. Cox proportional hazards regression analysis showed that pre-transplantation serum phosphate level was a risk factor for renal death (p<0.05), while serum potassium levels and weight gain were not. In addition, fluctuation of calcineurin inhibitor concentration was observed in patients with higher phosphate levels before transplantation (p=0.03). Weight gain after transplantation was not associated with the hemodialysis nonadherence factors.

Conclusions

High pre-transplantation serum phosphate levels are considered to represent poor drug adherence and/or an unhealthy lifestyle. Patient education that conveys the importance of adhering to medications and provides nutritional guidance is crucial for improving post-transplantation renal prognosis.

Psychosocial Mediators between Socioeconomic Status and Dietary Restrictions among Patients Receiving Hemodialysis in Japan

The generalizability of differences in dietary restrictions (DRs) as function of socioeconomic status (SES) and the pathways of the associations between SES and DRs remain unclear. Therefore, we aimed to explore SES differences in DRs and psychosocial mediators between SES and DRs in Japanese patients receiving hemodialysis. This study was a cross-sectional survey of 6,644 outpatients (average age = 66.5 years; 65% males) of hemodialysis facilities across Japan. DRs were assessed by self-reported and objective measures, and SES was assessed based on education and income. Three psychosocial mediators were used: self-efficacy, control expectancy, and social support. Indirect influences of SES through the mediators were evaluated with a multiple mediator model. Although higher education was significantly associated with higher self-reported DRs, higher income was significantly associated with lower self-reported DRs. Significant SES differences in objective DRs were not observed. The relationships between education and self-reported DRs and objective DRs were significantly mediated by self-efficacy and/or control expectancy. The influences of income were mediated by social support. It becomes possible to design interventions targeting modifiable psychosocial factors including self-efficacy, control expectancy, and social support in order to reduce SES inequalities in DRs.

Development and preliminary results on the feasibility of a renal diet specific question prompt sheet for use in nephrology clinics

Background

Adherence to the diet prescription for chronic kidney disease is suboptimal. Interventions to improve dietary adherence suggest that improving communication between the patient and the health professional is fundamental to improving outcomes. Providing patients with a question prompt sheet prior to the consultation has been demonstrated to be an effective method for improving communication between patient and health professional. In the absence of a renal diet specific version, the aims of this study were to develop and test the feasibility of a renal diet specific question prompt sheet for use in nephrology clinics.

Methods

Phase one utilized social listening methodology, online content analysis and clinic observations to obtain an extensive list of frequently asked questions about the renal diet. Following refinement with health professionals, the draft question prompt sheet was then sent in Phase two to patients one week prior to their scheduled consultation with the renal dietitian. Feedback was obtained from patients, carers and dietitians using semi structured interviews post clinic consultation. Quantitative data was analyzed using counts and proportions, while free text responses were analyzed thematically.

Results

A total of 769 unique renal diet related questions were reduced to an 18-item question prompt sheet. Feedback from thirteen patients (six males), six carers and six dietitians involved in the preliminary feasibility study was overwhelmingly positive. The majority of patients found the question prompt sheet to be easy to understand and agreed it facilitated communication with the dietitian. All participants agreed that they would recommend use of question prompt sheet to other patients. Suggestions for future use included health professional training in use of the sheet, particularly about how to help patients prioritize their most important questions.

Conclusions

The 18-item renal diet question prompt sheet developed in this preliminary study appears to be a feasible tool for use in nephrology consultations especially by dietitians. Further research quantifying the impact on question asking and patient centeredness should be undertaken. In addition, user testing with patients from culturally diverse and low literacy backgrounds would be useful.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1231-3) contains supplementary material, which is available to authorized users.

Phosphate-control adherence in hemodialysis patients: current perspectives

OBJECTIVES

This review summarizes factors relevant for adherence to phosphate-control strategies in dialysis patients, and discusses interventions to overcome related challenges.

METHODS

A literature search including the terms "phosphorus", "phosphorus control", "hemo-dialysis", "phosphate binder medications", "phosphorus diet", "adherence", and "nonadherence" was undertaken using PubMed, PsycInfo, CINAHL, and Embase.

RESULTS

Hyperphosphatemia is associated with cardiovascular and all-cause mortality in dialysis patients. Management of hyperphosphatemia depends on phosphate binder medication therapy, a low-phosphorus diet, and dialysis. Phosphate binder therapy is associated with a survival benefit. Dietary restriction is complex because of the need to maintain adequate protein intake and, alone, is insufficient for phosphorus control. Similarly, conventional hemodialysis alone is insufficient for phosphorus control due to the kinetics of dialytic phosphorus removal. Thus, all three treatment approaches are important contributors, with dietary restriction and dialysis as adjuncts to the requisite phosphate binder therapy. Phosphate-control adherence rates are suboptimal and are influenced directly by patient, provider, and phosphorus-control strategy-related factors. Psychosocial factors have been implicated as influential "drivers" of adherence behaviors in dialysis patients, and factors based on self-motivation associate directly with adherence behavior. Higher-risk subgroups of nonadherent patients include younger dialysis patients and non-whites. Provider attitudes may be important - yet unaddressed - determinants of adherence behaviors of dialysis patients.

CONCLUSION

Adherence to phosphate binders, low-phosphorus diet, and dialysis prescription is suboptimal. Multicomponent strategies that concurrently address therapy-related factors such as side effects, patient factors targeting self-motivation, and provider factors to improve attitudes and delivery of culturally sensitive care show the most promise for long-term control of phosphorus levels. Moreover, it will be important to identify patients at highest risk for lack of control, and for programs to be ready to deliver flexible person-centered strategies through training and dedicated resources to align with the needs of all patients.

Qualitative exploration of the experiences of renal dietitians and how they help patients with end stage kidney disease to understand the renal diet

AIM

Dietary modification is integral to the management of end stage kidney disease. However, adherence to the renal diet is poor. Few studies have explored the perspectives of renal dietitians and how they work with patients to facilitate dietary change. The objectives of this study were to explore the experiences of renal dietitians about educating patients with end stage kidney disease; and to describe the strategies perceived to help patients understand the renal diet.

METHODS

Semi-structured interviews based on Sensemaking theory were conducted with renal dietitians (n = 27) working in Australia and New Zealand from a range of metropolitan, regional and remote areas.

RESULTS

Five major themes across two categories were derived from the data. The renal dietitians in this study experienced feelings of frustration, frequently worked in practice environments with limited or inadequate resources and perceived that establishing trust and demonstrating empathy were important to sense making. Renal dietitians helped patients make sense of and understand the diet by clarifying ambiguities and conflicting information; and simplifying complexity by using simple explanations, individualised advice and practical support. These strategies were considered critical to the renal diet sense making process.

CONCLUSIONS

The experience of providing renal diet advice to adults with end stage kidney disease was emotionally and professionally challenging. Alternative approaches to patient education may help dietitians to empower patients to better understand the renal diet. Further research exploring the experiences of learning about the renal diet from the patient and carer perspective would also help to inform future alternative approaches.

Experiences and Perspectives of Dietary Management Among Patients on Hemodialysis: An Interview Study

OBJECTIVES

Diet and fluid management can reduce mortality, serious comorbidities, and debilitating symptoms in patients on hemodialysis, but restrictions may also be a major burden, and nonadherence remains high. We aimed to describe the perspectives and experiences of patients on hemodialysis regarding their dietary management to understand both facilitators and barriers to adherence and to identify strategies to improve care.

DESIGN AND METHODS

Semi-structured interviews were conducted with 35 people on maintenance hemodialysis from six dialysis units in New South Wales, Australia. Transcripts were thematically analyzed using principles of grounded theory.

RESULTS

We identified 5 major themes. Two themes reflect barriers to dietary change: exacerbating disruption (adding to treatment burden, contradicting healthy eating, confused by fragmented advice, conflicting cultural norms, changing appetite and palate, isolation from family and friends) and losing control (crises derailing discipline, frustrated by failure, combating bodily need for hydration). Three themes represent enablers for dietary change: attaining health benefits (avoiding medical catastrophes, enhancing benefits of dialysis, alleviating and managing symptoms, improving health), achieving treatment goals (building familiarity and acceptance, flexibility and moderation, taking personal responsibility), and succeeding withsupport (leaning on family for strength, trusting expert guidance, empowered with flexible and practical advice, relying on reminders and cues, motivation through shared experience).

CONCLUSIONS

Patients on hemodialysis believe dietary control helps to reduce symptom burden and enhance general health and well-being, but competing medical and social issues coupled with contradictory and/or irrelevant dietary advice prevents them from implementing diet and fluid restrictions. Interventions involving collaborative multidisciplinary care including clinicians with dietetic expertise, and consistent information that addresses cultural and personal circumstances, may support adherence to dietary recommendations and improve outcomes.