Design and Rationale of HiLo: A Pragmatic, Randomized Trial of Phosphate Management for Patients Receiving Maintenance Hemodialysis

Explaining International Trends in Mortality on Hemodialysis Through Changes in Hemodialysis Practices in the Dialysis Outcomes and Practice Patterns Study (DOPPS)

RATIONALE & OBJECTIVE

Case-mix adjusted hemodialysis mortality has decreased since 1998. Many factors that influence mortality may have contributed to this trend and these associations may differ by continental region. We studied changes in hemodialysis facility practices over time and their potential role in mediating changes in patient survival.

STUDY DESIGN

Observational prospective cohort study.

SETTING & PARTICIPANTS

Adult hemodialysis patients treated in hemodialysis 500 facilities participating in the Dialysis Outcomes Practice Patterns Study (DOPPS) between 1999 and 2015 in the US, Japan, and 4 four European countries: Germany, Italy, Spain, and UK.

PREDICTORS

Four practice measures at each facility: the percentages of patients with Kt/V>1.2, interdialytic weight gain [IDWG]<5.7%, phosphorus<6 mg/dL, and using AV fistulae.

OUTCOMES

Patient survival.

ANALYTICAL APPROACH

Mediation analyses, adjusted for case mix, were conducted using 3-year study phase as the exposure and facility practice measures as potential mediators.

RESULTS

In Europe, we observed a 13% improvement in overall case-mix adjusted survival per decade. Trends in facility practice measures, especially Kt/V and phosphorus, explained 10% improvement in case-mix survival per decade, representing 77% (10% explained of 13% improvement) of the observed improvement. In Japan, 73% of the observed 12%/decade improvement in case-mix adjusted survival could be attributed to facility practices, especially Kt/V and IDWG. In the US, 56% of the observed 47%/decade improvement in case-mix adjusted survival could be attributed to facility practices, especially AV fistula use and phosphorus control.

LIMITATIONS

Unmeasured changes in the characteristics of the patient population over this period may confound the observed associations.

CONCLUSION

The improvements in adjusted hemodialysis patient survival in Europe, Japan, and the US from 1999 to 2015 can be largely explained by improvements in specific facility practices. Future changes in patient survival may be responsive to further evolution in the implementation of common clinical practices.

Cutting back on low-value health care practices supports sustainable kidney care

July 2023 marked the hottest month on record, underscoring the urgent need for action on climate change. The imperative to reduce carbon emissions extends to all sectors, including health care, with it being responsible for 5.5% of global emissions. In decarbonizing health care, although much attention has focused on greening health care infrastructure and procurement, less attention has focused on reducing emissions through demand-side management. An important key element of this is reducing low-value care, given that ≈20% of global health care expenditure is considered low value. "Value" in health care, however, is subjective and dependent on how health outcomes are regarded. This review, therefore, examines the 3 main value perspectives specific to health care. Clinical effectiveness defines low-value care as interventions that offer little to no benefit or have a risk of harm exceeding benefits. Cost-effectiveness compares health outcomes versus costs compared with an alternative treatment. In this case, low-value care is care greater than a societal willingness to pay for an additional unit of health (quality-adjusted life year). Last, community perspectives emphasize the value of shared decision-making and patient-centered care. These values sit within broader societal values of ethics and equity. Any reduction in low-value care should, therefore, also consider patient autonomy, societal value perspectives and opportunity costs, and equity. Deimplementing entrenched low-value care practices without unnecessarily compromising ethics and equity will require tailored strategies, education, and transparency.

The impact of accessibility to non-calcium-based phosphate binders and calcimimetics on mineral outcomes in patients receiving maintenance hemodialysis: A 10-year retrospective analysis of real-world data

INTRODUCTION

Hyperphosphatemia and hyperparathyroidism are common in end-stage kidney disease and are associated with poor outcomes. In addition to adequate dialysis, medications are usually required for optimum control of serum phosphate and parathyroid hormone (PTH) levels. The use of calcium-based phosphate binders (CBPBs) and active vitamin D is associated with an increase in serum calcium and worsening vascular calcification. To overcome these limitations, non-calcium-based phosphate binders (NCBPBs) and calcimimetics have been developed. However, the coverage for these new medications remains limited in several parts of the world due to the lack of patient-level outcome data and cost. The present study examined the differences in mineral outcomes between two main categories of healthcare programs that provided different coverage for medications used to control mineral and bone disorders (MBD). The Social Security/Universal Coverage (SS/UC) program covered only CBPBs and active vitamin D, whereas the Civil Servant/State Enterprise (CS/SE) program provided coverage of CBPBs, active vitamin D, NCBPBs, and calcimimetics.

METHODS

This 10-year retrospective cohort study examined the differences in mineral outcomes between two healthcare programs in maintenance hemodialysis patients. The differences in serum calcium, phosphate, and PTH levels, as well as the aortic arch calcification score, were analyzed according to dialysis vintage by linear mixed-effects regression analyses. The difference in the composite outcome of severe hyperparathyroidism and parathyroidectomy was analyzed by the Cox-proportional hazard regression model.

RESULTS

714 patients were included in the analyses (full cohort). Of these patients, 563 required at least one type of medication to control MBD (MBD medication subgroup). Serum calcium, phosphate, and the proportions of patients with hypercalcemia and hyperphosphatemia were substantially higher in the SS/UC group compared with the CS/SE group after appropriate adjustments for confounders in both the full cohort and the MBD medication subgroup. These findings were confirmed in propensity-score matched analyses. Higher parathyroid hormone levels and a higher rate of the composite endpoint of severe hyperparathyroidism and parathyroidectomy were also observed in the SS/UC group. A more rapid progression of aortic arch calcification was suggested in the SS/UC group, but between-group changes were not significant.

CONCLUSION

Patients under the healthcare program that did not cover the use of NCBPBs and calcimimetics showed higher serum calcium and phosphate levels and a more rapid progression of hyperparathyroidism. The difference in the progression of vascular calcification could not be confirmed in the present study.

Academy of Nutrition and Dietetics Commentary on the Phosphorus Recommendation in the KDOQI Clinical Practice Guidelines for Nutrition in CKD: 2020 Update

The Kidney Disease Outcomes Quality Initiative Clinical Practice Guidelines for Nutrition in Chronic Kidney Disease: 2020 Update recommends adjusting dietary phosphorus to maintain a serum phosphate goal for hemodialysis patients in the normal range (0.81 to 1.45 mmol/L [2.5 to 4.5 mg/dL]). This is lower than the serum phosphate goal used by many dialysis centers (0.97 to 1.78 mmol/L [3.0 and 5.5 mg/dL]). Although context and clinical judgment must always be considered when providing individualized care to patients, a guideline implementation study conducted from December 2020 to December 2022 found that, based on their documentation, registered dietitian nutritionists from two national dialysis chains are almost universally using dialysis center goals instead of the lower phosphate goal recommended by the guideline. This commentary discusses the possible barriers to implementing the Kidney Disease Outcomes Quality Initiative 2020 nutrition guideline's phosphorus recommendation and proposes a systems level approach to promote and support adoption of the recommendation. Calls to action for potential changes in clinician practices, organizational/institutional culture, and government regulations are put forth.

Oh, My Gut! New insights on the role of the gastrointestinal tract and the gut microbiome in chronic kidney disease-mineral and bone disorder

PURPOSE OF REVIEW

The aim of this review is to highlight recent evidence on the role of the gastrointestinal tract and gut microbiome on chronic kidney disease-mineral bone disorder (CKD-MBD) outcomes, including intestinal phosphorus absorption and sensing, and the effect of gut-oriented therapies.

RECENT FINDINGS

Recent evidence has revealed a complex interplay among mineral metabolism and novel gut-related factors, including paracellular intestinal phosphate absorption, the gut microbiome, and the immune system, prompting a reevaluation of treatment approaches for CKD-MBD. The inhibition of NHE3 limits phosphate transport in the intestine and may lead to changes in the gut microbiome. A study in rats with CKD showed that the supplementation of the fermentable dietary inulin delayed CKD-MBD, lowering circulating phosphorus and parathyroid hormone, reducing bone remodeling and improving cortical parameters, and lowering cardiovascular calcifications. In non-CKD preclinical studies, probiotics and prebiotics improved bone formation mediated through the effect of butyrate facilitating the differentiation of T cells into Tregs, and Tregs stimulating the osteogenic Wnt10b, and butyrate was also necessary for the parathyroid hormone (PTH) bone effects.

SUMMARY

Recent findings support multiple possible roles for gut-oriented therapies in addressing CKD-MBD prevention and management that should be further explored through clinical and translational studies.

Actioning the findings of hard endpoint clinical trials as they emerge in the realm of chronic kidney disease care: a review and a call to action

Fewer than half of patients treated with hemodialysis survive 5 years. Multiple therapeutics are used to address the complications of advanced chronic kidney disease but most have not been found to improve clinical outcomes. Clinical trials of treatment innovations for chronic kidney diseases and dialysis care have been suboptimal in number and quality. Recent trials are changing this trend. Practice and policy change when new evidence emerges remains frequently impeded by resource and organizational constraints and accordingly, clinical practice guidelines are updated years or decades after definitive evidence is produced. Ultimately, practice change in health systems is slow, leading to impaired uptake of effective medical interventions and lower value healthcare, although innovations in rapid guideline production are emerging. What can be done to ensure that conclusive evidence is taken up in practice, policy and healthcare funding? We use the example of the recently published hard endpoint study "Comparison of high-dose HDF with high-flux HD" (CONVINCE) (hemodiafiltration versus hemodialysis), to explain how a new trial can impact on medical knowledge and change in practices. We (i) assess how the trial can be placed in the context of the totality of the evidence, (ii) define whether or not further trials of convective dialysis therapies are still needed and (iii) examine whether the evidence for convective therapies is now ready to inform practice, policy and funding change. When looking at CONVINCE in the context of the totality of evidence, we show that it addresses dialysis quality improvement priorities and is consistent with other trials evaluating convective dialysis therapies, and that the evidence for convective dialysis therapies is now definitive. Once updated evidence for cost-effectiveness in specific healthcare settings and patient-reported outcomes become available, we should therefore determine whether or not clinical practice guidelines should recommend uptake of convective dialysis therapies routinely, and move on to evaluating other treatments.

The open system of FGF-23 at the crossroad between additional P-lowering therapy, anemia and inflammation: how to deal with the intact and the C-terminal assays?

Fibroblast growth factor 23 (FGF-23) has been associated with increased cardiovascular risk and poor survival in dialysis patients. It is well established that FGF-23 synthesis is directly induced by positive phosphate (P) balance. On the other hand, P-lowering treatments such as nutritional P restriction, P binders and dialysis are capable of reducing FGF-23 levels. However, there are many uncertainties regarding the possibility of adopting FGF-23 to guide the clinical decision-making process in the context of chronic kidney disease-mineral bone disorder (CKD-MBD). Furthermore, the best assay to adopt for measurement of FGF-23 levels (namely the intact vs the C-terminal one) remains to be determined, especially in conditions capable of altering the synthesis as well as the cleavage of the intact and biologically active molecule, as occurs in the presence of CKD and its complications. This Editorial discusses the main insights provided by the post hoc analysis of the NOPHOS trial, with particular attention given to evidence-based peculiarities of the intact and the C-terminal assays available for measuring FGF-23 levels, especially in patients receiving additive P-lowering therapy in the presence of inflammation, anemia and iron deficiency.

Target Trial Emulation to Improve Causal Inference from Observational Data: What, Why, and How?

ABSTRACT

Target trial emulation has drastically improved the quality of observational studies investigating the effects of interventions. Its ability to prevent avoidable biases that have plagued many observational analyses has contributed to its recent popularity. This review explains what target trial emulation is, why it should be the standard approach for causal observational studies that investigate interventions, and how to do a target trial emulation analysis. We discuss the merits of target trial emulation compared with often used, but biased analyses, as well as potential caveats, and provide clinicians and researchers with the tools to better interpret results from observational studies investigating the effects of interventions.

Overcoming barriers in the design and implementation of clinical trials for acute kidney injury: a report from the 2020 Kidney Disease Clinical Trialists meeting

Acute kidney injury (AKI) is a growing epidemic and is independently associated with increased risk of death, chronic kidney disease (CKD) and cardiovascular events. Randomized-controlled trials (RCTs) in this domain are notoriously challenging and many clinical studies in AKI have yielded inconclusive findings. Underlying this conundrum is the inherent heterogeneity of AKI in its etiology, presentation and course. AKI is best understood as a syndrome and identification of AKI subphenotypes is needed to elucidate the disease's myriad etiologies and to tailor effective prevention and treatment strategies. Conventional RCTs are logistically cumbersome and often feature highly selected patient populations that limit external generalizability and thus alternative trial designs should be considered when appropriate. In this narrative review of recent developments in AKI trials based on the Kidney Disease Clinical Trialists (KDCT) 2020 meeting, we discuss barriers to and strategies for improved design and implementation of clinical trials for AKI patients, including predictive and prognostic enrichment techniques, the use of pragmatic trials and adaptive trials.

Physiopathology of Phosphate Disorders

Intracellular phosphate is critical for cellular processes such as signaling, nucleic acid synthesis, and membrane function. Extracellular phosphate (Pi) is an important component of the skeleton. Normal levels of serum phosphate are maintained by the coordinated actions of 1,25-dihydroxyvitamin D3, parathyroid hormone and fibroblast growth factor-23, which intersect in the proximal tubule to control the reabsorption of phosphate via the sodium-phosphate cotransporters Npt2a and Npt2c. Furthermore, 1,25-dihydroxyvitamin D3 participates in the regulation of dietary phosphate absorption in the small intestine. Clinical manifestations associated with abnormal serum phosphate levels are common and occur as a result of genetic or acquired conditions affecting phosphate homeostasis. For example, chronic hypophosphatemia leads to osteomalacia in adults and rickets in children. Acute severe hypophosphatemia can affect multiple organs leading to rhabdomyolysis, respiratory dysfunction, and hemolysis. Patients with impaired kidney function, such as those with advanced CKD, have high prevalence of hyperphosphatemia, with approximately two-thirds of patients on chronic hemodialysis in the United States having serum phosphate levels above the recommended goal of 5.5 mg/dL, a cutoff associated with excess risk of cardiovascular complications. Furthermore, patients with advanced kidney disease and hyperphosphatemia (>6.5 mg/dL) have almost one-third excess risk of death than those with phosphate levels between 2.4 and 6.5 mg/dL. Given the complex mechanisms that regulate phosphate levels, the interventions to treat the various diseases associated with hypophosphatemia or hyperphosphatemia rely on the understanding of the underlying pathobiological mechanisms governing each patient condition.

Serum Phosphorus Level Rises in US Hemodialysis Patients Over the Past Decade: A DOPPS Special Report

Mineral bone disorder (MBD) is a frequent consequence of chronic kidney disease, more so in patients with kidney failure treated by kidney replacement therapy. Despite the wide availability of interventions to control serum phosphate and parathyroid hormone levels, unmet gaps remain on optimal targets and best practices, leading to international practice pattern variations over time. In this Special Report, we describe international trends from the Dialysis Outcomes and Practice Patterns Study (DOPPS) for MBD biomarkers and treatments from 2002-2021, including data from a group of 7 European countries (Belgium, France, Germany, Italy, Spain, Sweden, United Kingdom), Japan, and the United States. From 2002-2012, mean phosphate levels declined in Japan (5.6 to 5.2 mg/dL), Europe (5.5 to 4.9 mg/dL), and the United States (5.7 to 5.0 mg/dL). Since then, levels rose in the United States (to mean 5.6 mg/dL, 2021), were stable in Japan (5.3 mg/dL), and declined in Europe (4.8 mg/dL). In 2021, 52% (United States), 27% (Europe), and 39% (Japan) had phosphate >5.5 mg/dL. In the United States, overall phosphate binder use was stable (80%-84% over 2015-2021), and parathyroid hormone levels rose only modestly. Although these results potentially stem from pervasive knowledge gaps in clinical practice, the noteworthy steady increase in serum phosphate in the United States over the past decades may be consequential to patient outcomes, an uncertainty that hopefully will soon be addressed by ongoing clinical trials. The DOPPS will continue to monitor international trends as new interventions and strategies ensue for MBD management in chronic kidney disease.

Unmet needs in clinical trials in CKD: questions we have not answered and answers we have not questioned

Many advances have been made in the field of nephrology over the last decade. These include an increasing focus on patient-centred involvement in trials, exploration of innovative trial designs and methodology, the growth of personalized medicine and, most importantly, novel therapeutic agents that are disease-modifying for large groups of patients with and without diabetes and chronic kidney disease. Despite this progress, many questions remain unanswered and we have not critically evaluated some of our assumptions, practices and guidelines despite emerging evidence to challenge current paradigms and discrepant patient-preferred outcomes. How best to implement best practices, diagnose various conditions, examine better diagnostic tools, treat laboratory values versus patients and understand prediction equations in the clinical context remain unanswered. As we enter a new era in nephrology, there are extraordinary opportunities to change the culture and care. Rigorous research paradigms enabling both the generation and the use of new information should be explored. We identify here some key areas of interest and suggest renewed efforts to describe and address these gaps so that we can develop, design and execute trials of importance to all.

Phosphate balance during dialysis and after kidney transplantation in patients with chronic kidney disease

PURPOSE OF REVIEW

In patients with chronic kidney disease (CKD), hyperphosphatemia is associated with several adverse outcomes, including bone fragility and progression of kidney and cardiovascular disease. However, there is a knowledge gap regarding phosphate balance in CKD. This review explores its current state, depending on the stage of CKD, dialysis modalities, and the influence of kidney transplantation.

RECENT FINDINGS

Adequate phosphate control is one of the goals of treatment for CKD-mineral and bone disorder. However, ongoing studies are challenging the benefits of phosphate-lowering treatment. Nevertheless, the current therapy is based on dietary restriction, phosphate binders, and optimal removal by dialysis. In the face of limited adherence, due to the high pill burden, adjuvant options are under investigation. The recent discovery that intestinal absorption of phosphate is mostly paracellular when the intraluminal concentration is adequate might help explain why phosphate is still well absorbed in CKD, despite the lower levels of calcitriol.

SUMMARY

Future studies could confirm the benefits of phosphate control. Greater understanding of the complex distribution of phosphate among the body compartments will help us define a better therapeutic strategy in patients with CKD.

Non calcium phosphate binders - Is there any evidence of benefit

PURPOSE OF REVIEW

Low-level evidence and opinion-based clinical practice guidelines highlight the substantial uncertainty in the practice patterns of hyperphosphatemia management in patients with chronic kidney disease (CKD). This manuscript reviews the evidence for the choice of phosphate binders and its impact on clinical outcomes.

RECENT FINDINGS

Phosphate binders are among the most common medications prescribed for patients on dialysis. Clinical practice guidelines recommend lowering phosphate levels toward normal range and restricting calcium-based binders in all CKD patients. There is substantial gap in the evidence underlying these recommendations with lack of any placebo-controlled, randomized trials showing survival benefits for any class of phosphate-binders. Despite the lack of evidence for specific phosphate target or if lowering phosphate improves survival, use of phosphate binders has remained central strategy in approach to hyperphosphatemia. Use of binders has added to the cost and contributed significant pill burden. Restriction of calcium-based binders to avoid positive calcium balance and consequent vascular calcification risk has a physiological rationale and weight of observational studies.

SUMMARY

There is currently no conclusive evidence that definitively guides the choice of any specific binders for management of hyperphosphatemia in patients with CKD. Use of noncalcium-based binders has a theoretical advantage in restricting total calcium intake to decrease the risk of vascular calcification but no proven benefits for mortality.

Past, Present, and Future of Phosphate Management

Cardiovascular (CV) disease (CVD) accounts for >50% of deaths with known causes in patients on dialysis. Elevated serum phosphorus levels are an important nontraditional risk factor for bone mineral disease and CVD in patients with chronic kidney disease (CKD). Given that phosphorus concentrations drive other disorders associated with increased CV risk (e.g., endothelial dysfunction, vascular calcification, fibroblast growth factor-23, parathyroid hormone), phosphate is a logical target to improve CV health. Phosphate binders are the only pharmacologic treatment approved for hyperphosphatemia. Although their safety has improved since inception, the mechanism of action leads to characteristics that make ingestion difficult and unpleasant; large pill size, objectionable taste, and multiple pills required for each meal and snack make phosphate binders a burden. Side effects, especially those affecting the gastrointestinal (GI) system, are common with binders, often leading to treatment discontinuation. The presence of “hidden” phosphates in processed foods and certain medications makes phosphate management even more challenging. Owing to these significant issues, most patients on dialysis are not consistently achieving and maintaining target phosphorus concentrations of <5.5 mg/dl, let alone more normal levels of <4.5 mg/dl, indicating novel approaches to improve phosphate management and CV health are needed. Several new nonbinder therapies that target intestinal phosphate absorption pathways have been developed. These include EOS789, which acts on the transcellular pathway, and tenapanor, which targets the dominant paracellular pathway. As observational evidence has established a strong association between phosphorus concentration and clinical outcomes, such as mortality, phosphate is an important target for improving the health of patients with CKD and end-stage kidney disease (ESKD).

Long-Term Effects of Sevelamer on Vascular Calcification, Arterial Stiffness, and Calcification Propensity in Patients Receiving Peritoneal Dialysis: The Randomized Pilot SERENE (Sevelamer on Vascular Calcification, Arterial Stiffness) Trial

Rationale & Objective

There is a concern regarding increased risk of vascular calcification with the use of calcium-based phosphorus binders. This study aimed to compare the effects of sevelamer used as a second-line, low-dose therapy with calcium-based phosphorus binders with those of sevelamer used as a first-line, high-dose therapy on coronary artery and heart valve calcification, aortic pulse wave velocity (PWV), and calcification propensity over 2 years in patients with hyperphosphatemia receiving peritoneal dialysis (PD).

Study Design

A 2-year-long prospective, multicenter, open-label, randomized pilot study.

Setting & Participants

Prevalent patients with hyperphosphatemia receiving PD from 2 university-affiliated hospitals in Hong Kong.

Interventions

The patients were randomized to receive sevelamer either as a first-line therapy at a high dose of 800 mg thrice daily (can titrate up to 1,200 mg thrice daily as required) or a second-line therapy at a low dose of 400 mg thrice daily with calcium carbonate to achieve a serum phosphorus target of ≤5.5 mg/dL.

Outcomes

The primary endpoints were changes in coronary artery calcium score and aortic PWV over 104 weeks. The secondary endpoints were changes in heart valve calcium scores, calcification propensity measure, and biochemical parameters of chronic kidney disease–mineral bone disease over 104 weeks.

Results

Among 60 prevalent patients receiving PD, with a mean age of 53 ± 10 years and with 57% men, changes in the coronary artery calcium score (median [interquartile range], 225 [79-525] vs 223 [56-1,212], respectively; P = 0.21), aortic PWV (mean ± standard error, 0.3 ± 0.1 vs 0.8 ± 0.2 m/s, respectively; P = 0.31), heart valve calcium score, maturation or transformation time, serum calcium levels, and phosphorus levels over 104 weeks were similar for the second-line, low-dose and first-line, high-dose sevelamer groups. Alkaline phosphatase and intact parathyroid hormone levels increased and low-density lipoprotein cholesterol decreased in both the groups, with no significant between-group differences.

Limitations

The sample size was small, and the dropout rates were relatively high.

Conclusions

Low-dose sevelamer used as a second-line therapy for hyperphosphatemia in combination with a calcium-based phosphorus binder had similar effects on vascular calcification, valvular calcification, and arterial stiffness compared with high-dose sevelamer used as a first-line therapy. This approach may be considered in resource-constrained countries to minimize calcium loading.

Funding

The study was supported by a competitive grant from SK Yee Medical Foundation. T50 assays and other biochemical assays were funded by a research grant from Sanofi Renal Corporation.

Trial Registration

NCT00745589.

Enhancing the use of EHR systems for pragmatic embedded research: lessons from the NIH Health Care Systems Research Collaboratory

OBJECTIVE

We identified challenges and solutions to using electronic health record (EHR) systems for the design and conduct of pragmatic research.

MATERIALS AND METHODS

Since 2012, the Health Care Systems Research Collaboratory has served as the resource coordinating center for 21 pragmatic clinical trial demonstration projects. The EHR Core working group invited these demonstration projects to complete a written semistructured survey and used an inductive approach to review responses and identify EHR-related challenges and suggested EHR enhancements.

RESULTS

We received survey responses from 20 projects and identified 21 challenges that fell into 6 broad themes: (1) inadequate collection of patient-reported outcome data, (2) lack of structured data collection, (3) data standardization, (4) resources to support customization of EHRs, (5) difficulties aggregating data across sites, and (6) accessing EHR data.

DISCUSSION

Based on these findings, we formulated 6 prerequisites for PCTs that would enable the conduct of pragmatic research: (1) integrate the collection of patient-centered data into EHR systems, (2) facilitate structured research data collection by leveraging standard EHR functions, usable interfaces, and standard workflows, (3) support the creation of high-quality research data by using standards, (4) ensure adequate IT staff to support embedded research, (5) create aggregate, multidata type resources for multisite trials, and (6) create re-usable and automated queries.

CONCLUSION

We are hopeful our collection of specific EHR challenges and research needs will drive health system leaders, policymakers, and EHR designers to support these suggestions to improve our national capacity for generating real-world evidence.

Patient Partner Perspectives Regarding Ethically and Clinically Important Aspects of Trial Design in Pragmatic Cluster Randomized Trials for Hemodialysis

BACKGROUND

Cluster randomized trials (CRTs) are trials in which intact groups such as hemodialysis centers or shifts are randomized to treatment or control arms. Pragmatic CRTs have been promoted as a promising trial design for nephrology research yet may also pose ethical challenges. While randomization occurs at the cluster level, the intervention and data collection may vary in a CRT, challenging the identification of research participants. Moreover, when a waiver of patient consent is granted by a research ethics committee, there is an open question as to whether and to what degree patients should be notified about ongoing research or be provided with a debrief regarding the nature and results of the trial upon completion. While empirical and conceptual research exploring ethical issues in pragmatic CRTs has begun to emerge, there has been limited discussion with patients, families, or caregivers of patients undergoing hemodialysis.

OBJECTIVE

To explore with patients and families with experience of hemodialysis research the challenges raised by different approaches to designing pragmatic CRTs in hemodialysis. Specifically, their perceptions of (1) the use of a waiver of consent, (2) notification processes and information provided to participants, and (3) any other concerns about cluster randomized designs in hemodialysis.

DESIGN

Focus group and interview discussions of hypothetical clinical trial designs.

SETTING

Focus groups and interviews were conducted in-person or via videoconference or telephone.

PARTICIPANTS

Patient partners in hemodialysis research, defined as patients with personal experience of dialysis or a family member who had experience supporting a patient receiving hemodialysis, who have been actively involved in discussions to advise a research team on the design, conduct, or implementation of a hemodialysis trial.

METHODS

Participants were invited to participate in focus groups or individual discussions that were audio recorded with consent. Recorded interviews were transcribed verbatim prior to analysis. Transcripts were analyzed using a thematic analysis approach.

RESULTS

Two focus groups, three individual interviews, and one interview involving a patient and family member were conducted with 17 individuals between February 2019 and May 2020. Participants expressed support for approaches that emphasized patient choice. Disclosure of patient-relevant risks and information were key themes. Both consent and notification processes served to generate trust, but bypassing patient choice was perceived as undermining this trust. Participants did not dismiss the option of a waiver of consent. They were, however, more restrictive in their views about when a waiver of consent may be acceptable. Patient partners were skeptical of claims to impracticability based on costs or the time commitments for staff.

LIMITATIONS

All participants were from Canada and had been involved in the design or conduct of a trial, limiting the degree to which results may be extrapolated.

CONCLUSIONS

Given the preferences of participants to be afforded the opportunity to decide about trial participation, we argue that investigators should thoroughly investigate approaches that allow participants to make an informed choice regarding trial participation. In keeping with the preference for autonomous choice, there remains a need to further explore how consent approaches can be designed to facilitate clinical trial conduct while meeting their ethical requirements. Finally, further work is needed to define the limited circumstances in which waivers of consent are appropriate.

Serum phosphate and mortality in incident dialysis patients in Australia and New Zealand

AIM

Hyperphosphataemia is associated with increased adverse outcomes, including mortality. Re-examining this association using up-to-date data reflecting current and real-world practices, across different global regions and in both haemodialysis and peritoneal dialysis patients, is important.

METHODS

We describe the association between serum phosphate and all-cause and cardiovascular mortality in incident dialysis patients between 2008 and 2018 using the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry. Time-dependent Cox proportionate hazards models were used. Models were adjusted for available covariates and fitted for the overall cohort, and also each dialysis modality.

RESULTS

31 989 patients were followed over 97 122 person-years at risk (mean age at first dialysis 61 years, 38% female, 67% haemodialysis). We observed a U-shaped association between serum phosphate and all-cause mortality. In the fully adjusted model, categories of serum phosphate above and below 1.25-1.99 mmol/L were associated with progressively higher risk, reaching a hazard ratio of 2.13 (95% CI 1.93-2.36, p < .001) for serum phosphate ≥2.75 mmol/L, and 1.56 (95% CI 1.44-1.69, p < .001) for serum phosphate <1.00 mmol/L. Low and high levels of serum phosphate were also associated with increased risk of cardiovascular mortality, however the association with high serum phosphate was more pronounced ("J-shaped relationship"). The associations were consistent across sub-analyses of patients receiving haemodialysis and peritoneal dialysis treatment.

CONCLUSION

In this large contemporary dialysis cohort, both high and low levels of serum phosphate were independently associated with increased risk of mortality. Future studies are required to determine whether treatment of abnormal serum phosphate levels improves mortality.