Concentration properties of biopolymers via dead-end forward osmosis.

Extracellular polymeric substances (EPSs) in excess sludge of wastewater treatment plants are valuable biopolymers that can act as recovery materials. However, effectively concentrating EPSs consumes a significant amount of energy. This study employed novel energy-saving pressure-free dead-end forward osmosis (DEFO) technology to concentrate various biopolymers, including EPSs and model biopolymers [sodium alginate (SA), bovine serum albumin (BSA), and a mixture of both (denoted as BSA-SA)]. The feasibility of the DEFO technology was proven and the largest concentration ratios for these biopolymers were 94.8 % for EPSs, 97.1 % for SA, 97.8 % for BSA, and 98.4 % for BSA-SA solutions. An evaluation model was proposed, incorporating the FO membrane's water permeability coefficient and the concentrated substances' osmotic resistance, to describe biopolymers' concentration properties. Irrespective of biopolymer type, the water permeability coefficient decreased with increasing osmotic pressure, remained constant with increasing feed solution (FS) concentration, increased with increasing crossing velocity in the draw side, and showed little dependence on draw salt type. In the EPS DEFO concentration process, osmotic resistance was minimally impacted by osmotic pressure, FS concentration, and crossing velocity, and monovalent metal salts were proposed as draw solutes. The interaction between reverse diffusion metal cations and EPSs affected the structure of the concentrated substances on the FO membrane, thus changing the osmotic resistance in the DEFO process. These findings offer insights into the efficient concentration of biopolymers using DEFO.

Defining systolic blood pressure normative values in hospitalized pediatric patients: a single center experience.

BACKGROUND: Normative blood pressure (BP) values and definition of hypertension (HTN) in children in outpatient setting cannot be reliably used for inpatient therapy initiation. No normative exists to describe HTN in hospitalized pediatric populations. We aimed to study the prevalence of hypertension and produce normative BP values in hospitalized children. METHODS: Cross sectional observational study of all children hospitalized on acute care floors, ≥2 and <18 years age, at Stanford Children's Hospital, from Jan-01-2014 to Dec-31-2018. Cohort included 7468 hospital encounters with a total of 118,423 automated, oscillometric, BPs measured in the upper extremity during a hospitalization of >24 hours. RESULTS: Overall prevalence of HTN, defined by outpatient guidelines, was 12-48% in boys and 6-39% in girls, stage 1 systolic HTN in 12-38% of boys and 6-31% of girls, stage 2 systolic HTN in 3-10% of boys and 1-8% of girls. Centile curves were derived demonstrating overall higher BP reading for hospitalized patients compared to the outpatient setting. CONCLUSION: Higher blood pressures are anticipated during hospitalization. Thresholds provided by the centile curves generated in this study may provide the clinician with some guidance on how to manage hospitalized pediatric patients based on clinical circumstances. IMPACT: Hospitalized children have higher blood pressures compared to patients in the ambulatory setting, hence outpatient normative blood pressure values cannot be reliably used for inpatient therapy initiation. No normative exists to describe hypertension in hospitalized pediatric populations. The thresholds provided by the centile curves generated in this study may provide the clinician with some guidance on how to manage hospitalized pediatric patients based on clinical circumstances.

Comparative effectiveness of sodium-glucose cotransporter-2 inhibitors versus glucagon-like peptide-1 receptor agonists in patients with type 2 diabetes and mild/moderate chronic kidney disease.

AIM: To determine the comparative effectiveness regarding major cardiovascular events of glucagon-like peptide-1 (GLP-1) receptor agonists and sodium-glucose cotransporter-2 (SGLT-2) inhibitors in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD). MATERIALS AND METHODS: We assembled a cohort of commercially insured adult patients with T2DM in the United States (derived from Optum Clinformatics DataMart 2003-2021) who were new users of GLP-1 receptor agonists or SGLT-2 inhibitors. We compared risks of non-fatal myocardial infarction or stroke in patients with and without CKD, and further categorized by CKD stage: stages G1 or G2 [estimated glomerular filtration rate (eGFR) ≥60 ml/min] and A2 (urine albumin to creatinine ratio 30 to <300 mg/g) or A3 (urine albumin to creatinine ratio ≥300 mg/g), stage G3a (eGFR 45 to <60 ml/min/1.73 m2 ) and stage G3b (eGFR 30 to <45 ml/min/1.73 m2 ). We used proportional hazards regression after inverse probability of treatment weighting to compute hazard ratios and 95% confidence intervals. RESULTS: After accounting for the probability of treatment, patients with T2DM and CKD treated with SGLT-2 inhibitors experienced a 14% lower risk of non-fatal myocardial infarction or stroke (hazard ratio 0.86, 95% confidence interval 0.78-0.94) relative to those treated with GLP-1 receptor agonists. CONCLUSIONS: Recognizing the potential for residual confounding, selection bias and immortal time bias, commercially insured patients in the United States with T2DM and CKD treated with SGLT-2 inhibitors experienced significantly lower risks of non-fatal myocardial infarction or stroke relative to those treated with GLP-1 receptor agonists.

Are patients with primary glomerular disease at increased risk of malignancy?

Over the past decade, several observational studies and case series have provided evidence suggesting a connection between glomerular diseases (GN) and the development of malignancies, with an estimated risk ranging from 5%-11%. These malignancies include solid organ tumors as well as hematologic malignancies such as lymphoma and leukemia. However, these risk estimates are subject to several sources of bias, including unmeasured confounding from inadequate exploration of risk factors, inclusion of GN cases that were potentially secondary to an underlying malignancy, misclassification of GN type, and ascertainment bias arising from an increased likelihood of physician encounters compared to the general population. Consequently, population-based studies that accurately evaluate the cancer risk in GN populations are lacking. While it is speculated that long-term use of immunosuppressive medications and GN disease activity measured by proteinuria and estimated glomerular filtration rate may be associated with cancer risk in patients with GN, the independent role of these risk factors remains largely unknown. The presence of these knowledge gaps could lead to (i) lack of awareness of cancer as a potential chronic complication of GN, (ii) under-utilization of routine screening practices in clinical care that allow early diagnosis and treatment of malignancies, and (iii) under-recognition of modifiable risk factors to decrease the risk of de novo malignancies over time. This review summarizes the current evidence on the risk of cancer in patients with GN, explores the limitations of prior studies, and discusses methodological challenges and potential solutions for obtaining accurate estimates of cancer risk and identifying modifiable risk factors unique to GN populations.

"Diving in the deep-end and swimming": a mixed methods study using normalization process theory to evaluate a learning collaborative approach for the implementation of palliative care practices in hemodialysis centers.

BACKGROUND: Normalization Process Theory (NPT) is an implementation theory that can be used to explain how and why implementation strategies work or not in particular circumstances. We used it to understand the mechanisms that lead to the adoption and routinization of palliative care within hemodialysis centers. METHODS: We employed a longitudinal, mixed methods approach to comprehensively evaluate the implementation of palliative care practices among ten hemodialysis centers participating in an Institute for Healthcare Improvement Breakthrough- Series learning collaborative. Qualitative methods included longitudinal observations of collaborative activities, and interviews with implementers at the end of the study. We used an inductive and deductive approach to thematic analysis informed by NPT constructs (coherence, cognitive participation, collective action, reflexive monitoring) and implementation outcomes. The NoMAD survey, which measures NPT constructs, was completed by implementers at each hemodialysis center during early and late implementation. RESULTS: The four mechanisms posited in NPT had a dynamic and layered relationship during the implementation process. Collaborative participants participated because they believed in the value and legitimacy of palliative care for patients receiving hemodialysis and thus had high levels of cognitive participation at the start. Didactic Learning Sessions were important for building practice coherence, and sense-making was solidified through testing new skills in practice and first-hand observation during coaching visits by an expert. Collective action was hampered by limited time among team members and practical issues such as arranging meetings with patients. Reflexive monitoring of the positive benefit to patient and family experiences was key in shifting mindsets from disease-centric towards a patient-centered model of care. NoMAD survey scores showed modest improvement over time, with collective action having the lowest scores. CONCLUSIONS: NPT was a useful framework for understanding the implementation of palliative care practices within hemodialysis centers. We found a nonlinear relationship among the mechanisms which is reflected in our model of implementation of palliative care practices through a learning collaborative. These findings suggest that the implementation of complex practices such as palliative care may be more successful through iterative learning and practice opportunities as the mechanisms for change are layered and mutually reinforcing. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04125537 . Registered 14 October 2019 - Retrospectively registered.

Endovascular versus Surgical Lower Extremity Revascularization among Patients with Chronic Kidney Disease.

Introduction: Patients with chronic kidney disease (CKD) have a high prevalence of peripheral artery disease. How best to manage lower extremity peripheral artery disease remains unclear in this patient population. We therefore sought to compare the outcomes after endovascular versus surgical lower extremity revascularization among patients with CKD. Methods: We used data from Optum's de-identifed Clinformatics® Data Mart Database, a nationwide database of commercially insured persons in the United States to study patients with CKD who underwent lower extremity endovascular or surgical revascularization. We used inverse probability of treatment weighting to balance covariates. We employed proportional hazard regression to study the primary outcome of major adverse limb events (MALE), defined as a repeat revascularization or amputation. We also studied each of these events separately and death from any cause. Results: In our cohort, 60,057 patients underwent endovascular revascularization and 9,338 patients underwent surgical revascularization. Endovascular revascularization compared with surgical revascularization was associated with a higher adjusted hazard of MALE (hazard ratio (HR) 1.52; 95% confidence interval (CI) 1.46-1.59). Endovascular revascularization was also associated with a higher adjusted hazard of repeat revascularization (HR 1.65; 95% CI 1.57-1.72) but a lower adjusted risk of amputation (HR 0.71; CI 0.73-0.89). Patients undergoing endovascular revascularization also had a lower adjusted hazard for death from any cause (0.85; CI 0.82-0.88). Conclusions: In this analysis of patients with CKD undergoing lower extremity revascularization, an endovascular approach was associated with a higher rate of repeated revascularization but a lower risk of subsequent amputation and death compared with surgical revascularization. Multiple factors must be considered when counseling patients with CKD, who have a high burden of comorbid conditions. Clinical trials should include more patients with kidney disease, who are often otherwise excluded from participation, to better understand the most effective treatment strategies for this vulnerable patient population.

MgFe-LDH@biochars for removing ammonia nitrogen and phosphorus from biogas slurry: Synthesis routes, composite performance, and adsorption mechanisms.

Layered double hydroxide-biochar composites (LDH@BCs) have been developed for ammonia nitrogen (AN) and phosphorus (P) removal from wastewater. Improvement of LDH@BCs was limited due to the lack of comparative evaluation based on LDH@BCs characteristics and synthetic methods and information on the adsorption properties of LDH@BCs for N and P from natural wastewater. In this study, MgFe-LDH@BCs were synthesized by three different co-precipitation procedures. The differences in physicochemical and morphological properties were compared. They were then employed to remove AN and P from biogas slurry. The adsorption performance of the three MgFe-LDH@BCs was compared and evaluated. Different synthesis procedures can significantly affect the physicochemical and morphological characteristics of MgFe-LDH@BCs. The LDH@BC composite fabricated through a novel method (labeled 'MgFe-LDH@BC1') has the largest specific surface area, Mg and Fe content, and excellent magnetic response performance. Moreover, the composite has the best adsorption property of AN and P from biogas slurry (30.0% and 81.8%, respectively). The main reaction mechanisms include memory effect, ion exchange, and co-precipitation. Applying 2% MgFe-LDH@BC1 saturated with AN and P adsorption from biogas slurry as a fertilizer substitute can substantially improve soil fertility and increase plant production by 139.3%. These results indicate that the facile LDH@BC synthesis method is an effective method to overcome the shortcomings of LDH@BC in practical application, and provide a basis for further exploration of the potential application of biochar based fertilizers in agriculture.

Calcium Alginate Production through Forward Osmosis with Reverse Solute Diffusion and Mechanism Analysis.

Calcium alginate (Ca-Alg) is a novel target product for recovering alginate from aerobic granular sludge. A novel Ca-Alg production method was proposed herein where Ca-Alg was formed in a sodium alginate (SA) feed solution (FS) and concentrated via forward osmosis (FO) with Ca2+ reverse osmosis using a draw solution of CaCl2. An abnormal reverse solute diffusion was observed, with the average reverse solute flux (RSF) decreasing with increasing CaCl2 concentrations, while the average RSF increased with increasing alginate concentrations. The RSF of Ca2+ in FS decreased continuously as the FO progressed, using 1.0 g/L SA as the FS, while it increased initially and later decreased using 2.0 and 3.0 g/L SA as the FS. These results were attributed to the Ca-Alg recovery production (CARP) formed on the FO membrane surface on the feed side, and the percentage of Ca2+ in CARP to total Ca2+ reverse osmosis reached 36.28%. Scanning electron microscopy and energy dispersive spectroscopy also verified CARP existence and its Ca2+ content. The thin film composite FO membrane with a supporting polysulfone electrospinning nanofiber membrane layer showed high water flux and RSF of Ca2+, which was proposed as a novel FO membrane for Ca-Alg production via the FO process with Ca2+ reverse diffusion. Four mechanisms including molecular sieve role, electrification of colloids, osmotic pressure of ions in CARP, and FO membrane structure were proposed to control the Ca-Alg production. Thus, the results provide further insights into Ca-Alg production via FO along with Ca2+ reverse osmosis.

Association of Pretransplant Coronary Heart Disease Testing With Early Kidney Transplant Outcomes.

Importance: Testing for coronary heart disease (CHD) in asymptomatic kidney transplant candidates before transplant is widespread and endorsed by various professional societies, but its association with perioperative outcomes is unclear. Objective: To estimate the association of pretransplant CHD testing with rates of death and myocardial infarction (MI). Design, Setting, and Participants: This retrospective cohort study included all adult, first-time kidney transplant recipients from January 2000 through December 2014 in the US Renal Data System with at least 1 year of Medicare enrollment before and after transplant. An instrumental variable (IV) analysis was used, with the program-level CHD testing rate in the year of the transplant as the IV. Analyses were stratified by study period, as the rate of CHD testing varied over time. A combination of US Renal Data System variables and Medicare claims was used to ascertain exposure, IV, covariates, and outcomes. Exposures: Receipt of nonurgent invasive or noninvasive CHD testing during the 12 months preceding kidney transplant. Main Outcomes and Measures: The primary outcome was a composite of death or acute MI within 30 days of after kidney transplant. Results: The cohort comprised 79 334 adult, first-time kidney transplant recipients (30 147 women [38%]; 25 387 [21%] Black and 48 394 [61%] White individuals; mean [SD] age of 56 [14] years during 2012 to 2014). The primary outcome occurred in 4604 patients (244 [5.3%]; 120 [2.6%] death, 134 [2.9%] acute MI). During the most recent study period (2012-2014), the CHD testing rate was 56% in patients in the most test-intensive transplant programs (fifth IV quintile) and 24% in patients at the least test-intensive transplant program (first IV quintile, P < .001); this pattern was similar across other study periods. In the main IV analysis, compared with no testing, CHD testing was not associated with a change in the rate of primary outcome (rate difference, 1.9%; 95% CI, 0%-3.5%). The results were similar across study periods, except for 2000 to 2003, during which CHD testing was associated with a higher event rate (rate difference, 6.8%; 95% CI, 1.8%-12.0%). Conclusions and Relevance: The results of this cohort study suggest that pretransplant CHD testing was not associated with a reduction in early posttransplant death or acute MI. The study findings potentially challenge the ubiquity of CHD testing before kidney transplant and should be confirmed in interventional studies.

Recovery of Extracellular Polymeric Substances from Excess Sludge Using High-Flux Electrospun Nanofiber Membranes.

The recycling of extracellular polymeric substances (EPSs) from excess sludge in wastewater treatment plants has received increasing attention in recent years. Although membrane separation has great potential for use in EPS concentration and recovery, conventional membranes tend to exhibit low water flux and high energy consumption. Herein, electrospun nanofiber membranes (ENMs) were fabricated using polyvinylidene fluoride (PVDF) and used for the recovery of EPSs extracted from the excess sludge using the cation exchange resin (CER) method. The fabricated ENM containing 14 wt.% PVDF showed excellent properties, with a high average water flux (376.8 L/(m2·h)) and an excellent EPS recovery rate (94.1%) in the dead-end filtration of a 1.0 g/L EPS solution at 20 kPa. The ENMs displayed excellent mechanical strength, antifouling properties, and high reusability after five recycles. The filtration pressure had a negligible effect on the average EPS recovery rate and water flux. The novel dead-end filtration with an EPS filter cake on the ENM surface was effective in removing heavy-metal ions, with the removal rates of Pb2+, Cu2+, and Cr6+ being 89.5%, 73.5%, and 74.6%, respectively. These results indicate the potential of nanofiber membranes for use in effective concentration and recycling of EPSs via membrane separation.

An evaluation method for product design solutions for healthy aging companionship.

Background: With the development trend of healthy aging and intelligent integration, escort products have become a new means of healthy aging. Healthy old-age care pays attention to the convenience and informatization of life. To meet the needs, designers often design multiple accompanying product solutions, and it is very important to use reasonable evaluation methods to decide on the optimal solution. Purposes: A new comprehensive evaluation method is proposed to reduce the subjectivity and one-sidedness of the selection process of intelligent escort product design solutions, and to make the decision more objective and reasonable. Such decisions can enhance the experience and naturalness of the elderly using intelligent products. Methods: First, a large number of user interviews were analyzed using the grounded theory, gradually refine through theoretical coding, and abstracted with the design scheme evaluation index. Second, the idea of game-theoretic weighting is used to optimize a linear combination of subjective and objective weights to determine the final weights of each evaluation indicator. Finally, the evaluation and selection are completed based on the solution ranking determined by the approximate ideal solution ranking method (TOPSIS). It is applied for the selection of the elderly escort robot design, and the usability test is conducted using the PSSUQ to verify the selection results. Results: A new comprehensive evaluation method can better complete the preferential selection of product design solutions for healthy aging escorts, and reduce the subjectivity and one-sidedness of the evaluation. Conclusion: This method compensates for the reliance on personal experience in the selection of options, and improve the subjectivity of the evaluation index determination process and the deviation of index weighting. Improving the objectivity and scientificity of decision-making reduces the blindness of design and production. It also provides a theoretical reference for the research scholars of healthy aging companion products.

Implementation and Effectiveness of a Learning Collaborative to Improve Palliative Care for Seriously Ill Hemodialysis Patients.

BACKGROUND AND OBJECTIVES: Limited implementation of palliative care practices in hemodialysis may contribute to end-of-life care that is intensive and not patient centered. We determined whether a learning collaborative for hemodialysis center providers improved delivery of palliative care best practices. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Ten US hemodialysis centers participated in a pre-post study targeting seriously ill patients between April 2019 and September 2020. Three practices were prioritized: screening for serious illness, goals of care discussions, and use of a palliative dialysis care pathway. The collaborative educational bundle consisted of learning sessions, communication skills training, and implementation support. The primary outcome was change in the probability of complete advance care planning documentation among seriously ill patients. Health care utilization was a secondary outcome, and implementation outcomes of acceptability, adoption, feasibility, and penetration were assessed using mixed methods. RESULTS: One center dropped out due to the coronavirus disease 2019 pandemic. Among the remaining nine centers, 20% (273 of 1395) of patients were identified as seriously ill preimplementation, and 16% (203 of 1254) were identified as seriously ill postimplementation. From the preimplementation to postimplementation period, the adjusted probability of complete advance care planning documentation among seriously ill patients increased by 34.5 percentage points (95% confidence interval, 4.4 to 68.5). There was no difference in mortality or in utilization of palliative hemodialysis, hospice referral, or hemodialysis discontinuation. Screening for serious illness was widely adopted, and goals of care discussions were adopted with incomplete integration. There was limited adoption of a palliative dialysis care pathway. CONCLUSIONS: A learning collaborative for hemodialysis centers spanning the coronavirus disease 2019 pandemic was associated with adoption of serious illness screening and goals of care discussions as well as improved documentation of advance care planning for seriously ill patients. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Pathways Project: Kidney Supportive Care, NCT04125537.

SARS-CoV-2 Infection during the Omicron Surge among Patients Receiving Dialysis: The Role of Circulating Receptor-Binding Domain Antibodies and Vaccine Doses.

BACKGROUND: It is unclear whether circulating antibody levels conferred protection against SARS-CoV-2 infection among patients receiving dialysis during the Omicron-dominant period. METHODS: We followed monthly semiquantitative SARS-CoV-2 RBD IgG index values in a randomly selected nationwide cohort of patients receiving dialysis and ascertained SARS-CoV-2 infection during the Omicron-dominant period of December 25, 2021 to January 31, 2022 using electronic health records. We estimated the relative risk for documented SARS-CoV-2 infection by vaccination status and by circulating RBD IgG using a log-binomial model accounting for age, sex, and prior COVID-19. RESULTS: Among 3576 patients receiving dialysis, 901 (25%) received a third mRNA vaccine dose as of December 24, 2021. Early antibody responses to third doses were robust (median peak index IgG value at assay limit of 150). During the Omicron-dominant period, SARS-CoV-2 infection was documented in 340 (7%) patients. Risk for infection was higher among patients without vaccination and with one to two doses (RR, 2.1; 95% CI, 1.6 to 2.8, and RR, 1.3; 95% CI, 1.0 to 1.8 versus three doses, respectively). Irrespective of the number of vaccine doses, risk for infection was higher among patients with circulating RBD IgG <23 (506 BAU/ml) (RR range, 2.1 to 3.2, 95% CI, 1.3 to 3.4 and 95% CI, 2.2 to 4.5, respectively) compared with RBD IgG ≥23. CONCLUSIONS: Among patients receiving dialysis, a third mRNA vaccine dose enhanced protection against SARS-CoV-2 infection during the Omicron-dominant period, but a low circulating RBD antibody response was associated with risk for infection independent of the number of vaccine doses. Measuring circulating antibody levels in this high-risk group could inform optimal timing of vaccination and other measures to reduce risk of SARS-CoV-2 infection.

Trends in Coronary Artery Disease Screening before Kidney Transplantation.

Background: Coronary artery disease (CAD) screening in asymptomatic kidney transplant candidates is widespread but not well supported by contemporary cardiology literature. In this study we describe temporal trends in CAD screening before kidney transplant in the United States. Methods: Using the United States Renal Data System, we examined Medicare-insured adults who received a first kidney transplant from 2000 through 2015. We stratified analysis on the basis of whether the patient's comorbidity burden met guideline definitions of high risk for CAD. We examined temporal trends in nonurgent CAD tests within the year before transplant and the composite of death and nonfatal myocardial infarction in the 30 days after transplant. Results: Of 94,832 kidney transplant recipients, 37,139 (39%) underwent at least one nonurgent CAD test in the 1 year before transplant. From 2000 to 2015, the transplant program waitlist volume had increased as transplant volume stayed constant, whereas patients in the later eras had a slightly higher comorbidity burden (older, longer dialysis vintage, and a higher prevalence of diabetes mellitus and CAD). The likelihood of CAD test in the year before transplant increased from 2000 through 2003 and remained relatively stable thereafter. When stratified by CAD risk status, test rates decreased modestly in patients who were high risk but remained constant in patients who were low risk after 2008. Death or nonfatal myocardial infarction within 30 days after transplant decreased from 3% in 2000 to 2% in 2015. Nuclear perfusion scan was the most frequent modality of testing throughout the examined time periods. Conclusions: CAD testing rates before kidney transplantation have remained constant from 2000 through 2015, despite widespread changes in cardiology guidelines and practice.

Trends in Cost Attributable to Kidney Transplantation Evaluation and Waiting List Management in the United States, 2012-2017.

Importance: While recent policy reforms aim to improve access to kidney transplantation for patients with end-stage kidney disease, the cost implications of kidney waiting list expansion are not well understood. The Organ Acquisition Cost Center (OACC) is the mechanism by which Medicare reimburses kidney transplantation programs, at cost, for costs attributable to kidney transplantation evaluation and waiting list management, but these costs have not been well described to date. Objectives: To describe temporal trends in mean OACC costs per kidney transplantation and to identify factors most associated with cost. Design, Setting, and Participants: This economic evaluation included all kidney transplantation waiting list candidates and recipients in the United States from 2012 to 2017. A population-based study of cost center reports was conducted using data from all Center of Medicare & Medicaid-certified transplantation hospitals. Data analysis was conducted from June to August 2021. Exposures: Year, local price index, transplantation and waiting list volume of transplantation program, and comorbidity burden. Main Outcomes and Measures: Mean OACC costs per kidney transplantation. Results: In 1335 hospital-years from 2012 through 2017, Medicare's share of OACC costs increased from $0.95 billion in 2012 to $1.32 billion in 2017 (3.7% of total Medicare End-Stage Renal Disease program expenditure). Median (IQR) OACC costs per transplantation increased from $81 000 ($66 000 to $103 000) in 2012 to $100 000 ($82 000 to $125 000) in 2017. Kidney organ procurement costs contributed to 36% of mean OACC costs per transplantation throughout the study period. During the study period, transplantation hospitals experienced increases in kidney waiting list volume, kidney waiting list active volume, kidney transplantation volume, and comorbidity burden. For a median-sized transplantation program, mean OACC costs per transplantation decreased with more transplants (-$3500 [95% CI, -$4300 to -$2700] per 10 transplants; P < .001) and increased with year ($4400 [95% CI, $3500 to $5300] per year; P < .001), local price index ($1900 [95% CI, $200 to $3700] per 10-point increase; P = .03), patients listed active on the waiting list ($3100 [95% CI, $1700 to $4600] per 100 patients; P < .001), and patients on the waiting list with high comorbidities ($1500 [9% CI, $600 to $2500] per 1% increase in proportion of waitlisted patients with the highest comorbidity score; P = .002). Conclusions and Relevance: In this study, OACC costs increased at 4% per year from 2012 to 2017 and were not solely attributable to the cost of organ procurement. Expanding the waiting list will likely contribute to further increases in the mean OACC costs per transplantation and substantially increase Medicare liability.

SARS-CoV-2 infection during the Omicron surge among patients receiving dialysis: the role of circulating receptor-binding domain antibodies and vaccine doses.

Background: It is unclear whether a third dose of mRNA platform vaccines, or antibody response to prior infection or vaccination confer protection from the Omicron variant among patients receiving dialysis. Methods: Monthly since February 2021, we tested plasma from 4,697 patients receiving dialysis for antibodies to the receptor-binding domain (RBD) of SARS-CoV-2. We assessed semiquantitative median IgG index values over time among patients vaccinated with at least one dose of the two mRNA vaccines. We ascertained documented COVID-19 diagnoses after December 25, 2021 and up to January 31, 2022. We estimated the relative risk for documented SARS-CoV-2 infection by vaccination status using a log-binomial model accounting for age, sex, and prior clinical COVID-19. Among patients with RBD IgG index value available during December 1-December 24, 2021, we also evaluated the association between the circulating RBD IgG titer and risk for Omicron variant SARS-CoV-2 infection. Results: Of the 4,697 patients we followed with monthly RBD assays, 3576 are included in the main analysis cohort; among these, 852 (24%) were unvaccinated. Antibody response to third doses was robust (median peak index IgG value at assay limit of 150, equivalent to 3270 binding antibody units/mL). Between December 25-January 31, 2022, SARS-CoV-2 infection was documented 340 patients (7%), 115 (36%) of whom were hospitalized. The final doses of vaccines were given a median of 272 (25 th , 75 th percentile, 245-303) days and 58 (25 th , 75 th percentile, 51-95) days prior to infection for the 1-2 dose and 3 dose vaccine groups respectively. Relative risks for infection were higher among patients without vaccination (RR 2.1 [95%CI 1.6, 2.8]), and patients with 1-2 doses (RR 1.3 [95%CI 1.0, 1.8]), compared with patients with three doses of the mRNA vaccines. Relative risks for infection were higher among patients with RBD index values < 23 (506 BAU/mL), compared with RBD index value ≥ 23 (RR 2.4 [95%CI 1.9, 3.0]). The higher risk for infection among patients with RBD index values < 23 was present among patients who received three doses (RR 2.1 [95%CI 1.3, 3.4]). Conclusions: Among patients receiving hemodialysis, patients unvaccinated, without a third mRNA vaccine dose, or those lacking robust circulating antibody response are at higher risk for Omicron variant infection. Low circulating antibodies could identify the subgroup needing intensified surveillance, prophylaxis or treatment in this patient population.

Cardiovascular outcomes associated with prescription of sodium-glucose co-transporter-2 inhibitors versus dipeptidyl peptidase-4 inhibitors in patients with diabetes and chronic kidney disease.

AIM: To determine the association with cardiovascular (CV) outcomes of sodium-glucose co-transporter-2 (SGLT-2) inhibitors compared with dipeptidyl peptidase-4 (DPP-4) inhibitors in patients with type 2 diabetes (T2D) and chronic kidney disease (CKD). MATERIALS AND METHODS: We conducted a population-based cohort study of new users of SGLT-2 inhibitors and DPP-4 inhibitors with T2D and CKD using data from Optum Clinformatics DataMart. We assembled three cohorts: T2D/no CKD, T2D/CKD 1-2, and T2D/CKD 3a. The study outcomes were (a) time to first heart failure (HF) hospitalization and (b) time to a composite CV endpoint comprised of non-fatal myocardial infarction (MI) or stroke. After inverse probability of treatment weighting, we used proportional hazards regression to estimate hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: New users of SGLT-2 inhibitors versus DPP-4 inhibitors had lower risks of HF hospitalization in the T2D/no CKD (HR, 0.76; 95% CI, 0.70, 0.82) and T2D/CKD 1-2 (HR, 0.63; 95% CI, 0.48, 0.84) cohorts, but no significant association was present in the T2D/CKD 3a cohort. Compared with prescription of DPP-4 inhibitors, SGLT-2 inhibitors were associated with lower risks of non-fatal MI or stroke of 23% (HR, 0.77; 95% CI, 0.70, 0.85) in the T2D/no CKD cohort, but no significant associations were present in the T2D/CKD 1-2 and T2D/CKD 3a cohorts. CONCLUSIONS: Incident prescription of SGLT-2 inhibitors was associated with lower risks of HF hospitalization but not with non-fatal MI or stroke despite suggesting benefit, relative to prescription of DPP-4 inhibitor across different stages of CKD.

SARS-CoV-2 Vaccine Antibody Response and Breakthrough Infection in Patients Receiving Dialysis.

BACKGROUND: Whether breakthrough SARS-CoV-2 infections after vaccination are related to the level of postvaccine circulating antibody is unclear. OBJECTIVE: To determine longitudinal antibody-based response and risk for breakthrough infection after SARS-CoV-2 vaccination. DESIGN: Prospective study. SETTING: Nationwide sample from dialysis facilities. PATIENTS: 4791 patients receiving dialysis. MEASUREMENTS: Remainder plasma from a laboratory processing routine monthly tests was used to measure qualitative and semiquantitative antibodies to the receptor-binding domain (RBD) of SARS-CoV-2. To evaluate whether peak or prebreakthrough RBD values were associated with breakthrough infection, a nested case-control analysis matched each breakthrough case patient to 5 control patients by age, sex, and vaccination month and adjusted for diabetes status and region of residence. RESULTS: Of the 4791 patients followed with monthly RBD assays, 2563 were vaccinated as of 14 September 2021. Among the vaccinated patients, the estimated proportion with an undetectable RBD response increased from 6.6% (95% CI, 5.5% to 7.8%) 14 to 30 days after vaccination to 20.2% (CI, 17.0% to 23.3%) 5 to 6 months after vaccination. Estimated median index values decreased from 91.9 (CI, 78.6 to 105.2) 14 to 30 days after vaccination to 8.4 (CI, 7.6 to 9.3) 5 to 6 months after vaccination. Breakthrough infections occurred in 56 patients, with samples collected a median of 21 days before breakthrough infection. Compared with prebreakthrough index RBD values of 23 or higher (equivalent to ≥506 binding antibody units per milliliter), prebreakthrough RBD values less than 10 and values from 10 to less than 23 were associated with higher odds for breakthrough infection (rate ratios, 11.6 [CI, 3.4 to 39.5] and 6.0 [CI, 1.5 to 23.6], respectively). LIMITATIONS: Single measure of vaccine response; ascertainment of COVID-19 diagnosis from electronic health records. CONCLUSION: The antibody response to SARS-CoV-2 vaccination wanes rapidly in persons receiving dialysis. In this population, the circulating antibody response is associated with risk for breakthrough infection. PRIMARY FUNDING SOURCE: Ascend Clinical Laboratory.