International variations in serum PTH and calcium levels and their mortality associations in peritoneal dialysis patients: Results from PDOPPS.

BACKGROUND: Mineral bone disorder (MBD) in chronic kidney disease (CKD) is associated with high symptom burden, fractures, vascular calcification, cardiovascular disease and increased morbidity and mortality. CKD-MBD studies have been limited in peritoneal dialysis (PD) patients. Here, we describe calcium and parathyroid hormone (PTH) control, related treatments and mortality associations in PD patients. METHODS: We used data from eight countries (Australia and New Zealand (A/NZ), Canada, Japan, Thailand, South Korea, United Kingdom, United States (US)) participating in the prospective cohort Peritoneal Dialysis Outcomes and Practice Patterns Study (2014-2022) among patients receiving PD for >3 months. We analysed the association of baseline PTH and albumin-adjusted calcium (calciumAlb) with all-cause mortality using Cox regression, adjusted for potential confounders, including serum phosphorus and alkaline phosphatase. RESULTS: Mean age ranged from 54.6 years in South Korea to 63.5 years in Japan. PTH and serum calciumAlb were measured at baseline in 12,642 and 14,244 patients, respectively. Median PTH ranged from 161 (Japan) to 363 pg/mL (US); mean calciumAlb ranged from 9.1 (South Korea, US) to 9.8 mg/dL (A/NZ). The PTH/mortality relationship was U-shaped, with the lowest risk at PTH 300-599 pg/mL. Mortality was nearly 20% higher at serum calciumAlb 9.6+ mg/dL versus 8.4-<9.6 mg/dL. MBD therapy prescriptions varied substantially across countries. CONCLUSIONS: A large proportion of PD patients in this multi-national study have calcium and/or PTH levels in ranges associated with substantially higher mortality. These observations point to the need to substantially improve MBD management in PD to optimise patient outcomes. LAY SUMMARY: Chronic kidney disease-mineral bone disorder (MBD) is a systemic condition, common in dialysis patients, that results in abnormalities in parathyroid hormone (PTH), calcium, phosphorus and vitamin D metabolism. A large proportion of peritoneal dialysis (PD) patients in this current multi-national study had calcium and/or PTH levels in ranges associated with substantially higher risks of death. Our observational study design limits our ability to determine whether these abnormal calcium and PTH levels cause more death due to possible confounding that was not accounted for in our analysis. However, our findings, along with other recent work showing 48-75% higher risk of death for the one-third of PD patients having high phosphorus levels (>5.5 mg/dL), should raise strong concerns for a greater focus on improving MBD management in PD patients.

The Burden of Home Dialysis: An Overlooked Challenge.

Home dialysis offers several clinical and quality-of-life benefits for patients with kidney failure. However, it is important to recognize that home dialysis may place an increased burden on patients and their care partners. Sources of burden may include concerns about the ability to adequately and safely perform dialysis at home, physical symptoms, impairment of life participation, psychosocial challenges, and care partner burnout. Overlooking or failing to address these issues may lead to adverse events that negatively affect health and quality of life and reduce longevity of home dialysis. This study will explore aspects of home dialysis associated with burden, emphasize the need for increased awareness of potential challenges, and elaborate on strategies to overcome sources of burden. Future research should actively involve patients and care partners to better understand their motivation, experiences, and needs to better inform support strategies.

Geographic Dialysis Facility Density and Early Dialysis Initiation.

Importance: The decision of when to start maintenance hemodialysis may be affected by health system-level support for high-intensity care as manifested by area dialysis facility density. Yet an association between early hemodialysis initiation and higher area density of dialysis facilities has not been shown. Objective: To examine whether there is an association between area dialysis facility density and earlier dialysis initiation. Design, Setting, and Participants: Cross-sectional analysis was conducted of publicly reported claims and geographic-based population data collected in the Medical Evidence files of the US Renal Data System (USRDS), a comprehensive registry of all patients initiating hemodialysis in the US, from calendar years 2011 through 2019. Data were linked to the American Community Survey, using residential zip codes, and then to health service area (HSA) primary care and hospitalization benchmarks, using the Dartmouth Atlas crosswalk. Data were analyzed from November 1, 2021, to August 31, 2023. Exposure: Dialysis facility density at the level of HSA (number of dialysis facilities per 100 000 HSA residents) split into 5 categories. Main Outcomes and Measures: The odds of hemodialysis initiation at an estimated glomerular filtration rate (eGFR) greater than 10 mL/min/1.73 m2 vs less than or equal to 10 mL/min/1.73 m2. Results: Hemodialysis was initiated in a total of 844 466 individuals at 3397 HSAs at a mean (SD) eGFR of 8.9 (3.8) mL/min/1.73 m2. Their mean (SD) age was 63.5 (14.7) years, and 484 346 participants (57.4%) were men. In the HSA category with the highest facility density, individuals were younger (63.3 vs 65.2 years in least-dense HSAs), poorer (mean percent of households living in poverty, 10.4% vs 8.4%), and more commonly had a higher percentage of Black individuals (40.6% vs 11.3%). More individuals in the dialysis-dense HSAs than least-dense HSAs had diabetes (60.1% vs 58.5%) and fewer had access to predialysis nephrology care (60.8% vs 64.1%); the rates of heart failure and immobility varied, but not in a consistent pattern, by HSA dialysis density. The mean (SD) facility density was 4.1 (1.89) centers per 100 000 population in the most dialysis-dense HSAs. Compared with patients in HSAs with a mean of 1.0 per 100 000 population, the odds of hemodialysis initiation at eGFR greater than 10 mL/min/1.73 m2 were 1.07 (95% CI, 1.03-1.11) for patients in the densest HSAs, and compared with HSAs with 0 facilities, the odds of early hemodialysis initiation were 1.06 (95% CI, 1.02-1.10) for patients in the densest HSAs. Conclusions and Relevance: In this cross-sectional study of USRDS- and HSA-level data, HSA dialysis density was associated with early hemodialysis initiation.

Differences in Outcomes by Place of Origin among Hispanic Patients with Kidney Failure.

SIGNIFICANCE STATEMENT: Hispanic patients are known to have a higher risk of kidney failure and lower rates of home dialysis use and kidney transplantation than non-Hispanic White patients. However, it is unknown whether these outcomes differ within the Hispanic community, which is heterogeneous in its members' places of origins. Using United States Renal Data System data, the authors found similar adjusted rates of home dialysis use for patients originating from places outside the United States and US-born Hispanic patients, whereas the adjusted risk of mortality and likelihood of transplantation differed depending on place (country or territory) of origin. Understanding the heterogeneity in kidney disease outcomes and treatment within the Hispanic community is crucial in designing interventions and implementation strategies to ensure that Hispanic individuals with kidney failure have equitable access to care. BACKGROUND: Compared with non-Hispanic White groups, Hispanic individuals have a higher risk of kidney failure yet lower rates of living donor transplantation and home dialysis. However, how home dialysis, mortality, and transplantation vary within the Hispanic community depending on patients' place of origin is unclear. METHODS: We identified adult Hispanic patients from the United States Renal Data System who initiated dialysis in 2009-2017. Primary exposure was country or territory of origin (the United States, Mexico, US-Puerto Rico, and other countries). We used logistic regression to estimate differences in odds of initiating home dialysis and competing risk models to estimate subdistribution hazard ratios (SHR) of mortality and kidney transplantation. RESULTS: Of 137,039 patients, 44.4% were US-born, 30.9% were from Mexico, 12.9% were from US-Puerto Rico, and 11.8% were from other countries. Home dialysis rates were higher among US-born patients, but not significantly different after adjusting for demographic, medical, socioeconomic, and facility-level factors. Adjusted mortality risk was higher for individuals from US-Puerto Rico (SHR, 1.04; 95% confidence interval [CI], 1.01 to 1.08) and lower for Mexico (SHR, 0.80; 95% CI, 0.78 to 0.81) and other countries (SHR, 0.83; 95% CI, 0.81 to 0.86) compared with US-born patients. The adjusted rate of transplantation for Mexican or US-Puerto Rican patients was similar to that of US-born patients but higher for those from other countries (SHR, 1.22; 95% CI, 1.15 to 1.30). CONCLUSIONS: Hispanic people from different places of origin have similar adjusted rates of home dialysis but different adjusted rates of mortality and kidney transplantation. Further research is needed to understand the mechanisms underlying these observed differences in outcomes.

Australian Workshops on Patients' Perspectives on Hemodialysis and Incremental Start.

Introduction: Most patients with kidney failure commence and continue hemodialysis (HD) thrice weekly. Incremental initiation (defined as HD less than thrice weekly) is increasingly considered to be safe and less burdensome, but little is known about patients' perspectives. We aimed to describe patients' priorities and concerns regarding incremental HD. Methods: Patients currently, previously, or soon to be receiving HD in Australia participated in two 90-minute online workshops to discuss views about HD focusing on incremental start and priorities for trial outcomes. Transcripts were analyzed using thematic analysis. Outcomes were ranked on the basis of the sum of participants' priority scores (i.e., single allocation of 3 points for most important, 2 for second, and 1 for third most important outcome). Results: All 26 participants (1 caregiver and 25 patients) preferred an incremental HD approach. The top prioritized outcomes were quality of life (QOL) (56 points), residual kidney function (RKF) (27 points), and mortality (16 points). The following 4 themes underpinning outcome priorities, experience, and safety concerns were identified: (i) unpreparedness and pressure to adapt, (ii) disruption to daily living, (iii) threats to safety, and (iv) hope and future planning. Conclusion: Patients with kidney failure preferred an incremental start to HD to minimize disruption to daily living and reduce the negative impacts on their education, ability to work, and family life. QOL was the most critically important outcome, followed by RKF and survival.

Peritoneal Dialysis-Associated Peritonitis Trends Using Medicare Claims Data, 2013-2017.

RATIONALE & OBJECTIVE: The occurrence and consequences of peritoneal dialysis (PD)-associated peritonitis limit its use in populations with kidney failure. Studies of large clinical populations may enhance our understanding of peritonitis. To facilitate these studies we developed an approach to measuring peritonitis rates using Medicare claims data to characterize peritonitis trends and identify its clinical risk factors. STUDY DESIGN: Retrospective cohort study of PD-associated peritonitis. SETTING & PARTICIPANTS: US Renal Data System standard analysis files were used for claims, eligibility, modality, and demographic information. The sample consisted of patients receiving PD treated at some time between 2013 and 2017 who were covered by Medicare fee-for-service (FFS) insurance with paid claims for dialysis or hospital services. EXPOSURES/PREDICTORS: Peritonitis risk was characterized by year, age, sex, race, ethnicity, vintage of kidney replacement therapy, cause of kidney failure, and prior peritonitis episodes. OUTCOME: The major outcome was peritonitis, identified using ICD-9 and ICD-10 diagnosis codes. Closely spaced peritonitis claims (30 days) were aggregated into 1 peritonitis episode. ANALYTICAL APPROACH: Patient-level risk factors for peritonitis were modeled using Poisson regression. RESULTS: We identified 70,271 peritonitis episodes from 396,289 peritonitis claims. Although various codes were used to record an episode of peritonitis, none was used predominantly. Peritonitis episodes were often identified by multiple aggregated claims, with the mean and median claims per episode being 5.6 and 2, respectively. We found 40% of episodes were exclusively outpatient, 9% exclusively inpatient, and 16% were exclusively based on codes that do not clearly distinguish peritonitis from catheter infections/inflammation ("catheter codes"). The overall peritonitis rate was 0.54 episodes per patient-year (EPPY). The rate was 0.45 EPPY after excluding catheter codes and 0.35 EPPY when limited to episodes that only included claims from nephrologists or dialysis providers. The peritonitis rate declined by 5%/year and varied by patient factors including age (lower rates at higher ages), race (Black > White>Asian), and prior peritonitis episodes (higher rate with each prior episode). LIMITATIONS: Coding heterogeneity indicates a lack of standardization. Episodes based exclusively on catheter codes could represent false positives. Peritonitis episodes were not validated against symptoms or microbiologic data. CONCLUSIONS: PD-associated peritonitis rates decline over time and were lower among older patients. A claims-based approach offers a promising framework for the study of PD-associated peritonitis.

Establishing a Core Outcome Measure for Peritoneal Dialysis-related Peritonitis: A Standardized Outcomes in Nephrology-Peritoneal Dialysis Consensus Workshop Report.

Introduction: Peritoneal dialysis (PD)-related peritonitis is one of the leading causes of discontinuation of PD and is considered a critically important outcome for patients on PD. However, there is no universally accepted method of measuring this outcome in clinical trials. Methods: We convened an online consensus workshop to establish a core outcome measure for PD-related peritonitis in clinical trials. Results: A total of 53 participants, including 18 patients and caregivers, from 12 countries engaged in breakout discussions in this workshop. Transcripts were analyzed thematically. We identified the following 3 themes: (i) feasibility and applicability across diverse settings, which reflected the difficulty with implementing laboratory-based measures in resource-limited environments; (ii) ensuring validity, which included minimizing false positives and considering the specificity of symptoms; and (iii) being meaningful and tangible to patients, which meant that the measure should be easy to interpret, reflect the impact that symptoms have on patients, and promote transparency by standardizing the reporting of peritonitis among dialysis units. Conclusion: A core outcome measure for PD-related peritonitis should include both symptom-based and laboratory-based criteria. Thus, the International Society for Peritoneal Dialysis (ISPD) definition of peritonitis is acceptable. However, there should be consideration of reporting suspected peritonitis in cases where laboratory confirmation is not possible. The measure should include all infections from the time of catheter insertion and capture both the rate of infection and the number of patients who remain peritonitis free. A core outcome measure with these features would increase the impact of clinical trials on the care and decision-making of patients receiving PD.

Variation in Peritoneal Dialysis Time on Therapy by Country: Results from the Peritoneal Dialysis Outcomes and Practice Patterns Study.

BACKGROUND AND OBJECTIVES: Quantifying contemporary peritoneal dialysis time on therapy is important for patients and providers. We describe time on peritoneal dialysis in the context of outcomes of hemodialysis transfer, death, and kidney transplantation on the basis of the multinational, observational Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) from 2014 to 2017. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Among 218 randomly selected peritoneal dialysis facilities (7121 patients) in the PDOPPS from Australia/New Zealand, Canada, Japan, Thailand, the United Kingdom, and the United States, we calculated the cumulative incidence from peritoneal dialysis start to hemodialysis transfer, death, or kidney transplantation over 5 years and adjusted hazard ratios for patient and facility factors associated with death and hemodialysis transfer. RESULTS: Median time on peritoneal dialysis ranged from 1.7 (interquartile range, 0.8-2.9; the United Kingdom) to 3.2 (interquartile range, 1.5-6.0; Japan) years and was longer with lower kidney transplantation rates (range: 32% [the United Kingdom] to 2% [Japan and Thailand] over 3 years). Adjusted hemodialysis transfer risk was lowest in Thailand, but death risk was higher in Thailand and the United States compared with most countries. Infection was the leading cause of hemodialysis transfer, with higher hemodialysis transfer risks seen in patients having psychiatric disorder history or elevated body mass index. The proportion of patients with total weekly Kt/V ≥1.7 at a facility was not associated with death or hemodialysis transfer. CONCLUSIONS: Countries in the PDOPPS with higher rates of kidney transplantation tended to have shorter median times on peritoneal dialysis. Identification of infection as a leading cause of hemodialysis transfer and patient and facility factors associated with the risk of hemodialysis transfer can facilitate interventions to reduce these events. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2022_05_31_CJN16341221.mp3.

Establishing a core outcome measure for life participation in patients receiving peritoneal dialysis: A Standardised Outcomes in Nephrology-Peritoneal Dialysis consensus workshop report.

BACKGROUND: Life participation is an outcome of critical importance to patients receiving peritoneal dialysis (PD). However, there is no widely accepted or validated tool for measuring life participation in patients receiving PD. METHODS: Online consensus workshop to identify the essential characteristics of life participation as a core outcome, with the goal of establishing a patient-reported outcome measure for use in all trials in patients receiving PD. Thematic analysis of transcripts was performed. RESULTS: Fifty-six participants, including 17 patients and caregivers, from 15 countries convened via online videoconference. Four themes were identified: reconfiguring expectations of daily living (accepting day-to-day fluctuation as the norm, shifting thresholds of acceptability, preserving gains in flexibility and freedom), ensuring broad applicability and interpretability (establishing cross-cultural relevance, incorporating valued activities, distinguishing unmodifiable barriers to life participation), capturing transitions between modalities and how they affect life participation (responsive to trajectory towards stable, reflecting changes with dialysis transitions) and maximising feasibility of implementation (reducing completion burden, administrable with ease and flexibility). CONCLUSIONS: There is a need for a validated, generalisable outcome measure for life participation in patients receiving PD. Feasibility, including length of time to complete and flexible mode of delivery, are important to allow implementation in all trials that include patients receiving PD.

Cost Barriers to More Widespread Use of Peritoneal Dialysis in the United States.

The United States Department of Health and Human Services launched the Advancing American Kidney Health Initiative in 2019, which included a goal of transforming dialysis care from an in-center to a largely home-based dialysis program. A substantial motivator for this transition is the potential to reduce costs of ESKD care with peritoneal dialysis. Studies demonstrating that peritoneal dialysis is less costly than in-center hemodialysis have often focused on the perspective of the payer, whereas less consideration has been given to the costs of those who are more directly involved in treatment decision making, including patients, caregivers, physicians, and dialysis facilities. We review comparisons of peritoneal dialysis and in-center hemodialysis costs, focusing on costs incurred by the people and organizations making decisions about dialysis modality, to highlight the financial barriers toward increased adoption of peritoneal dialysis. We specifically address misaligned economic incentives, underappreciated costs for key stakeholders involved in peritoneal dialysis delivery, differences in provider costs, and transition costs. We conclude by offering policy suggestions that include improving data collection to better understand costs in peritoneal dialysis, and sharing potential savings among all stakeholders, to incentivize a transition to peritoneal dialysis.

Spiritual well-being and its relationship with patient characteristics and other patient-reported outcomes in peritoneal dialysis patients: Findings from the PDOPPS.

BACKGROUND: Spiritual well-being (SWB), an individual's understanding of the meaning and purpose of life, may help patients with chronic or terminal illnesses cope with their diseases. This study aimed to assess SWB in patients on peritoneal dialysis (PD), as well as its relationship with patient characteristics and patient-reported outcomes (PRO). METHODS: The data were obtained from questionnaires that formed part of the PD Outcomes and Practice Patterns Study (PDOPPS). Measures used in this study were SWB scores derived from the WHO quality of life, spirituality, religiousness and personal beliefs (WHOQOL-SRPB) tool including 32 items from eight facets; physical (PCS) and mental component summary (MCS) scores of the 12-Item Short-Form Health Survey (SF-12), Center of Epidemiologic Studies Depression Scale-10 (CES-D-10) scores, burden of kidney disease scores and functional status scores. RESULTS: Overall, 529 out of 848 participants (62%) completely responded to the questionnaires and were included in the analysis. Over two-thirds of PD patients (70%) had moderate or higher SWB scores. The SWB scores were significantly lower in patients with age >65 years and unemployed status. SWB scores positively correlated with higher PCS, MCS, burden of kidney disease scores and functional status scores, while negatively correlated with depression scores by CES-D-10 scale. Patients who reported significant depressive symptoms (CES-D-10 score ≥ 10) had significantly lower SWB scores. CONCLUSION: Better SWB was significantly associated with better health-related QOL (HRQOL) and the absence of depressive symptoms. SWB may be an essential consideration in the delivery of high-quality PD.

A Focus Group Study of Self-Management in Patients With Glomerular Disease.

INTRODUCTION: Patients with glomerular disease experience symptoms that impair their physical and mental health while managing their treatments, diet, appointments and monitoring general and specific indicators of health and their illness. We sought to describe the perspectives of patients and their care partners on self-management in glomerular disease. METHODS: We conducted 16 focus groups involving adult patients with glomerular disease (n = 101) and their care partners (n = 34) in Australia, Hong Kong, the United Kingdom, and United States. Transcripts were analyzed thematically. RESULTS: We identified the following 4 themes: empowered in autonomy (gaining confidence through understanding, taking ownership of disease and treatment, learning a positive health approach); overwhelmed by compounding treatment burdens (financially undermined and depleted, demoralized by side effects and harms, frustrated by fragmented and inflexible care, fear of possible drug harms); striving for stability and normalcy (making personal sacrifices, maximizing life participation, attentiveness to bodily signs, avoiding precarious health states, integrating medicines into routines); and necessity of health-sustaining relationships (buoyed by social support, fulfilling meaningful responsibilities, sharing and normalizing experiences, seeking a trusting and respectful alliance). CONCLUSION: Patients with glomerular disease and their care partners value their capacity for autonomy and disease ownership, stability of their health, and relationships that support self-management. Strategies directed at strengthening these factors may increase self-efficacy and improve the care and outcomes for patients with glomerular disease.

Scalable Algorithms for Large Competing Risks Data.

This paper develops two orthogonal contributions to scalable sparse regression for competing risks time-to-event data. First, we study and accelerate the broken adaptive ridge method (BAR), a surrogate ℓ 0-based iteratively reweighted ℓ 2-penalization algorithm that achieves sparsity in its limit, in the context of the Fine-Gray (1999) proportional subdistributional hazards (PSH) model. In particular, we derive a new algorithm for BAR regression, named cycBAR, that performs cyclic update of each coordinate using an explicit thresholding formula. The new cycBAR algorithm effectively avoids fitting multiple reweighted ℓ 2-penalizations and thus yields impressive speedups over the original BAR algorithm. Second, we address a pivotal computational issue related to fitting the PSH model. Specifically, the computation costs of the log-pseudo likelihood and its derivatives for PSH model grow at the rate of O(n 2) with the sample size n in current implementations. We propose a novel forward-backward scan algorithm that reduces the computation costs to O(n). The proposed method applies to both unpenalized and penalized estimation for the PSH model and has exhibited drastic speedups over current implementations. Finally, combining the two algorithms can yields > 1, 000 fold speedups over the original BAR algorithm. Illustrations of the impressive scalability of our proposed algorithm for large competing risks data are given using both simulations and a United States Renal Data System data. Supplementary materials for this article are available online.

Establishing a Core Outcome Set for Autosomal Dominant Polycystic Kidney Disease: Report of the Standardized Outcomes in Nephrology-Polycystic Kidney Disease (SONG-PKD) Consensus Workshop.

The omission of outcomes that are of relevance to patients, clinicians, and regulators across trials in autosomal dominant polycystic kidney disease (ADPKD) limits shared decision making. The Standardized Outcomes in Nephrology-Polycystic Kidney Disease (SONG-PKD) Initiative convened an international consensus workshop on October 25, 2018, to discuss the identification and implementation of a potential core outcome set for all ADPKD trials. This article summarizes the discussion from the workshops and the SONG-PKD core outcome set. Key stakeholders including 11 patients/caregivers and 47 health professionals (nephrologists, policy makers, industry, and researchers) attended the workshop. Four themes emerged: "Relevance of trajectory and impact of kidney function" included concerns about a patient's prognosis and uncertainty of when they may need to commence kidney replacement therapy and the lack of an early prognostic marker to inform long-term decisions; "Discerning and defining pain specific to ADPKD" highlighted the challenges in determining the origin of pain, adapting to the chronicity and repeated episodes of pain, the need to place emphasis on pain management, and to have a validated measure for pain; "Highlighting ADPKD consequences" encompassed cyst-related complications and reflected patient's knowledge because of family history and the hereditary nature of ADPKD; and "Risk for life-threatening but rare consequences" such as cerebral aneurysm meant considering both frequency and severity of the outcome. Kidney function, mortality, cardiovascular disease, and pain were established as the core outcomes for ADPKD.