Comparison of COVID-19 Hospitalization and Death Between Solid Organ Transplant Recipients and the General Population in Canada, 2020-2022.

Background: Solid organ transplant recipients have a high risk of severe outcomes from SARS-CoV-2 infection. A comprehensive understanding of the impact of the COVID-19 pandemic across multiple waves in the solid organ transplant population and how this compares to the general population is limited. We conducted a population-based cohort study using linked administrative healthcare databases from Ontario, Canada to answer this question. Methods: We included 15 306 solid organ transplant recipients and 12 160 904 individuals from the general population. Our primary outcome was the rate (per 100 person-years) of severe COVID-19 (ie, hospitalization or death with a positive SARS-CoV-2 test) occurring between January 25, 2020, and November 30, 2022. Results: Compared with the general population, solid organ transplant recipients had almost a 6 times higher rate of severe COVID-19 (20.39 versus 3.44 per 100 person-years), with almost 5.5 times as high a rate of death alone (4.19 versus 0.77 per 100 person-years). Transplant recipients with severe COVID-19 were substantially younger (60.1 versus 66.5 y) and had more comorbidities. The rate of severe COVID-19 declined over time in the solid organ transplant population, with an incidence rate of 41.25 per 100 person-years in the first wave (January 25, 2020, to August 31, 2020) and 18.41 in the seventh wave (June 19, 2022, to November 30, 2022, Omicron era). Conclusions: Solid organ transplant recipients remain at high risk of severe outcomes when they are infected with SARS-CoV-2. Resources and strategies to mitigate the impact of SARS-CoV-2 exposure are needed in this vulnerable patient population.

Defining pre-emptive living kidney donor transplantation as a quality indicator.

Quality indicators in kidney transplants are needed to identify care gaps and improve access to transplants. We used linked administrative health care databases to examine multiple ways of defining pre-emptive living donor kidney transplants, including different patient cohorts and censoring definitions. We included adults from Ontario, Canada with advanced chronic kidney disease between January 1, 2013, to December 31, 2018. We created 4 unique incident patient cohorts, varying the eligibility by the risk of progression to kidney failure and whether individuals had a recorded contraindication to kidney transplant (eg, home oxygen use). We explored the effect of 4 censoring event definitions. Across the 4 cohorts, size varied substantially from 20 663 to 9598 patients, with the largest reduction (a 43% reduction) occurring when we excluded patients with ≥1 recorded contraindication to kidney transplantation. The incidence rate (per 100 person-years) of pre-emptive living donor kidney transplant varied across cohorts from 1.02 (95% CI: 0.91-1.14) for our most inclusive cohort to 2.21 (95% CI: 1.96-2.49) for the most restrictive cohort. Our methods can serve as a framework for developing other quality indicators in kidney transplantation and monitoring and improving access to pre-emptive living donor kidney transplants in health care systems.

Effectiveness of a Fourth COVID-19 mRNA Vaccine Dose Against the Omicron Variant in Solid Organ Transplant Recipients.

BACKGROUND: The effectiveness of booster doses of COVID-19 vaccines in solid organ transplant recipients is unclear. We conducted a population-based matched cohort study using linked administrative healthcare databases from Ontario, Canada to estimate the marginal vaccine effectiveness of a fourth versus third dose of the BNT162b2 and mRNA-1273 vaccines against clinically important outcomes (ie, hospitalization or death) and infection during the era of the Omicron variant. METHODS: We matched 3120 solid organ transplant recipients with a third COVID-19 vaccine dose (reference) to 3120 recipients with a fourth dose. Recipients were matched on the third dose date (±7 d). We used a multivariable Cox proportional hazards model to estimate the marginal vaccine effectiveness with outcomes occurring between December 21, 2021 and April 30, 2022. RESULTS: The cumulative incidence of COVID-19-related hospitalization or death was 2.8% (95% confidence interval [CI], 2.0-3.7) in the third dose group compared with 1.1% (95% CI, 0.59-1.8) in the fourth dose group after 84 d of follow-up (P < 0.001). The adjusted marginal vaccine effectiveness was 70% (95% CI, 47-83) against clinically important outcomes and 39% (95% CI, 21-52) against SARS-CoV-2 infection. CONCLUSIONS: Compared with a third dose, a fourth dose of the COVID-19 vaccine was associated with improved protection against hospitalization, death, and SARS-CoV-2 infection during the Omicron era. Results highlight the importance of a booster COVID-19 vaccine dose in solid organ transplant recipients.

Calcineurin Inhibition in Deceased Organ Donors: A Systematic Review and Meta-analysis of Preclinical Studies.

Background: Preconditioning deceased organ donors with calcineurin inhibitors (CNIs) may reduce ischemia-reperfusion injury to improve transplant outcomes. Methods: We searched MEDLINE, EMBASE, Cochrane Library, and conference proceedings for animal models of organ donation and transplantation, comparing donor treatment with CNIs with either placebo or no intervention, and evaluating outcomes for organ transplantation. Reviewers independently screened and selected studies, abstracted data, and assessed the risk of bias and clinical relevance of included studies. Where possible, we pooled results using meta-analysis; otherwise, we summarized findings descriptively. Results: Eighteen studies used various animals and a range of CNI agents and doses and evaluated their effects on a variety of transplant outcomes. The risk of bias and clinical applicability were poorly reported. Pooled analyses suggested benefit of CNI treatment on early graft function in renal transplants (3 studies; serum creatinine: ratio of means [RoM] 0.54; 95% confidence interval [CI], 0.34-0.86) but not for liver transplants (2 studies; serum alanine transaminase: RoM 0.61; 95% CI, 0.30-1.26; and serum aspartate aminotransferase: RoM 0.58; 95% CI, 0.26-1.31). We found no reduction in graft loss at 7 d (2 studies; risk ratio 0.54; 95% CI, 0.08-3.42). CNI treatment was associated with reduced transplant recipient levels of interleukin-6 (4 studies; RoM 0.36; 95% CI, 0.19-0.70), tumor necrosis factor-alpha (5 studies; RoM 0.36; 95% CI, 0.12-1.03), and cellular apoptosis (4 studies; RoM 0.30; 95% CI, 0.19-0.47). Conclusions: Although this compendium of animal experiments suggests that donor preconditioning with CNIs may improve early kidney graft function, the limited ability to reproduce a true clinical environment in animal experiments and to assess for risk of bias in these experiments is a serious weakness that precludes current clinical application.

Variation in Kidney Transplant Referral Across Chronic Kidney Disease Programs in Ontario, Canada.

Background: Eligible patients with kidney failure should have equal access to kidney transplantation. Transplant referral is the first crucial step toward receiving a kidney transplant; however, studies suggest substantial variation in the rate of kidney transplant referral across regions. The province of Ontario, Canada, has a public, single-payer health care system with 27 regional chronic kidney disease (CKD) programs. The probability of being referred for kidney transplant may not be equal across CKD programs. Objective: To determine whether there is variability in kidney transplant referral rates across Ontario's CKD programs. Design: Population-based cohort study using linked administrative health care databases from January 1, 2013, to November 1, 2016. Setting: Twenty-seven regional CKD programs in the province of Ontario, Canada. Patients: Patients approaching the need for dialysis (advanced CKD) and patients receiving maintenance dialysis (maximum follow-up: November 1, 2017). Measurements: Kidney transplant referral. Methods: We calculated the 1-year unadjusted cumulative probability of kidney transplant referral for Ontario's 27 CKD programs using the complement of Kaplan-Meier estimator. We calculated standardized referral ratios (SRRs) for each CKD program, using expected referrals from a 2-staged Cox proportional hazards model, adjusting for patient characteristics in the first stage. Standardized referral ratios with a value less than 1 were below the provincial average (maximum possible follow-up of 4 years 10 months). In an additional analysis, we grouped CKD programs according to 5 geographic regions. Results: Among 8641 patients with advanced CKD, the 1-year cumulative probability of kidney transplant referral ranged from 0.9% (95% confidence interval [CI]: 0.2%-3.7%) to 21.0% (95% CI: 17.5%-25.2%) across the 27 CKD programs. The adjusted SRR ranged from 0.2 (95% CI: 0.1-0.4) to 4.2 (95% CI: 2.1-7.5). Among 6852 patients receiving maintenance dialysis, the 1-year cumulative probability of transplant referral ranged from 6.4% (95% CI: 4.0%-10.2%) to 34.5% (95% CI: 29.5%-40.1%) across CKD programs. The adjusted SRR ranged from 0.2 (95% CI: 0.1-0.3) to 1.8 (95% CI: 1.6-2.1). When we grouped CKD programs according to geographic region, we found that patients residing in Northern regions had a substantially lower 1-year cumulative probability of transplant referral. Limitations: Our cumulative probability estimates only captured referrals within the first year of advanced CKD or maintenance dialysis initiation. Conclusions: There is marked variability in the probability of kidney transplant referral across CKD programs operating in a publicly funded health care system.

Contexte: Les patients atteints d'insuffisance rénale qui y sont admissibles devraient bénéficier d'un accès égal à la transplantation rénale. L'aiguillage vers un programme de transplantation est la première étape essentielle pour recevoir une greffe de rein. Des études suggèrent cependant qu'il existe des variations substantielles dans les taux d'aiguillage vers une greffe de rein selon les régions. La province de l'Ontario, au Canada, dispose d'un système public de santé à payeur unique comptant 27 programmes régionaux d'insuffisance rénale chronique (IRC). La probabilité d'être aiguillé vers une transplantation rénale n'est pas forcément la même dans tous les programmes d'IRC. Objectif: Déterminer s'il existe une variabilité dans les programmes d'IRC de l'Ontario en ce qui concerne les taux d'aiguillage vers une greffe de rein. Conception: Étude de cohorte représentative d'une population réalisée en Ontario (Canada) entre le 1er janvier 2013 et le 1er novembre 2016 à partir des données administratives en santé. Cadre: Les 27 programmes régionaux d'IRC de la province de l'Ontario (Canada). Sujets: Des patients approchant le besoin de dialyse (IRC de stade avancé) et des patients recevant des traitements de dialyse d'entretien (suivi maximum jusqu'au 1er novembre 2017). Mesures: L'aiguillage vers une greffe de rein. Méthodologie: Nous avons calculé la probabilité cumulative non ajustée d'être aiguillé à l'intérieur d'un an vers une transplantation rénale dans chacun des 27 programmes d'IRC de l'Ontario en utilisant le complément de l'estimateur Kaplan-Meier. Nous avons calculé les ratios d'aiguillage normalisés (SRR­Standardized Reference Ratios) des programmes d'IRC en utilisant les taux d'aiguillge attendus à partir d'un modèle de risques proportionnels de Cox en deux étapes, avec correction en fonction des caractéristiques du patient dans la première étape. Les ratios d'aiguillage normalisés d'une valeur inférieure à 1 étaient inférieurs à la moyenne provinciale (suivi maximum possible de 4 ans et 10 mois). Dans une analyse supplémentaire, nous avons regroupé les programmes d'IRC selon cinq régions géographiques. Résultats: Parmi les 8 641 patients atteints d'IRC de stade avancé, la probabilité cumulative d'aiguillage en un an pour une transplantation rénale variait de 0,9 % (IC 95 %: 0,2-3,7 %) à 21,0 % (IC 95 %: 17,5-25,2 %) pour l'ensemble des 27 programmes d'IRC. Le SRR corrigé variait de 0,2 (IC à 95 %: 0,1-0,4) à 4,2 (IC 95 %: 2,1-7,5). Parmi les 6 852 patients qui recevaient une dialyse d'entretien, la probabilité cumulative d'aiguillage en un an vers la transplantation variait de 6,4 % (IC 95 %: 4,0-10,2 %) à 34,5 % (IC 95 %: 29,5-40,1 %) pour l'ensemble des programmes d'IRC. Le SRR corrigé variait de 0,2 (IC 95 %: 0,1-0,3) à 1,8 (IC 95 %: 1,6-2,1). En regroupant les programmes d'IRC en fonction de la région géographique, nous avons constaté que les patients résidant dans les régions du Nord avaient une probabilité cumulative nettement plus faible d'être aiguillés vers la transplantation en un an. Limites: Nos estimations de la probabilité cumulative n'ont permis de saisir que les aiguillages au cours de la première année d'IRC de stade avancé ou de l'amorce d'une dialyse d'entretien. Conclusion: Il existe une variabilité marquée dans la probabilité d'être aiguillé vers une transplantation rénale dans les programmes d'IRC opérant dans un système de santé financé par l'État.

Development and Validation of a Predictive Risk Algorithm for Bleeding in Individuals on Long-term Hemodialysis: An International Prospective Cohort Study (BLEED-HD).

Background: Individuals with kidney disease are at a high risk of bleeding and as such tools that identify those at highest risk may aid mitigation strategies. Objective: We set out to develop and validate a prediction equation (BLEED-HD) to identify patients on maintenance hemodialysis at high risk of bleeding. Design: International prospective cohort study (development); retrospective cohort study (validation). Settings: Development: 15 countries (Dialysis Outcomes and Practice Patterns Study [DOPPS] phase 2-6 from 2002 to 2018); Validation: Ontario, Canada. Patients: Development: 53 147 patients; Validation: 19 318 patients. Measurements: Hospitalization for a bleeding event. Methods: Cox proportional hazards models. Results: Among the DOPPS cohort (mean age, 63.7 years; female, 39.7%), a bleeding event occurred in 2773 patients (5.2%, event rate 32 per 1000 person-years), with a median follow-up of 1.6 (interquartile range [IQR], 0.9-2.1) years. BLEED-HD included 6 variables: age, sex, country, previous gastrointestinal bleeding, prosthetic heart valve, and vitamin K antagonist use. The observed 3-year probability of bleeding by deciles of risk ranged from 2.2% to 10.8%. Model discrimination was low to moderate (c-statistic = 0.65) with excellent calibration (Brier score range = 0.036-0.095). Discrimination and calibration of BLEED-HD were similar in an external validation of 19 318 patients from Ontario, Canada. Compared to existing bleeding scores, BLEED-HD demonstrated better discrimination and calibration (c-statistic: HEMORRHAGE = 0.59, HAS-BLED = 0.59, and ATRIA = 0.57, c-stat difference, net reclassification index [NRI], and integrated discrimination index [IDI] all P value <.0001). Limitations: Dialysis procedure anticoagulation was not available; validation cohort was considerably older than the development cohort. Conclusion: In patients on maintenance hemodialysis, BLEED-HD is a simple risk equation that may be more applicable than existing risk tools in predicting the risk of bleeding in this high-risk population.

Contexte: Les personnes atteintes d'insuffisance rénale présentent un risque élevé d'hémorragie. Des outils permettant de déceler les personnes les plus exposées au risque pourrait aider à mettre en œuvre des stratégies d'atténuation. Objectifs: Nous avons mis au point et validé une équation prédictive (BLEED-HD) afin d'identifier les patients sous hémodialyse d'entretien qui présentent un risque élevé d'hémorragie. Type d'étude: Étude de cohorte prospective internationale (développement); étude de cohorte rétrospective (validation). Cadre: Développement: dans 15 pays (étude DOPPS phases 2 à 6 entre 2002 et 2018); validation: en Ontario (Canada). Sujets: Développement: 53 147 patients; validation: 19 318 patients. Mesures: Hospitalisation pour un événement hémorragique. Méthodologie: Modèles à risques proportionnels de Cox. Résultats: Dans la cohorte DOPPS (âge moyen: 63,7 ans; 39,7 % de femmes), 2 773 patients avaient subi un événement hémorragique (5,2 %; taux d'événements: 32 pour 1 000 années-personnes) avec un suivi médian de 1,6 an (ÉIQ: 0,9 à 2,1). BLEED-HD prend six variables en compte: âge, sexe, pays d'origine, saignement gastro-intestinal antérieur, présence d'une valve cardiaque prothétique et utilisation d'un antagoniste de la vitamine K. La probabilité observée de saignements dans les 3 ans par déciles de risque allait de 2,2 à 10,8 %. La discrimination du modèle variait de faible à modérée (statistique c: 0,65) avec un excellent étalonnage (plage de score de Brier: 0,036-0,095). La discrimination et l'étalonnage de se sont avérés semblables lors de la validation externe auprès de 19 318 patients de l'Ontario (Canada). Par rapport aux scores d'hémorragie existants, l'équation BLEED-HD a démontré une meilleure discrimination et un meilleur étalonnage (statistique c: HEMORRHAGE 0,59; HAS-BLED 0,59 et ATRIA 0,57; différence dans les c-stat, indices NRI et IDI toutes valeurs de p < 0,0001). Limites: L'information sur l'anticoagulant utilisé dans la procédure de dialyse n'était pas disponible; la cohorte de validation était beaucoup plus âgée que la cohorte de développement. Conclusion: Pour les patients sous hémodialyse d'entretien, BLEED-HD est une équation simple de calcul du risque qui peut être plus facilement applicable que les outils existants pour prédire le risque d'hémorragie dans cette population à haut risque.

Risk of venous thromboembolism or hemorrhage among individuals with chronic kidney disease on prophylactic anticoagulant after hip or knee arthroplasty.

Chronic kidney disease (CKD) confers a high risk of thrombosis and bleeding. However, little evidence exists regarding the optimal choice of postoperative thromboprophylaxis in these patients. We conducted a population-based, retrospective cohort study among adults ≥66 years old with CKD undergoing hip or knee arthroplasty who had filled an outpatient prophylactic anticoagulant prescription between 2010 and 2020 in Ontario, Canada. The primary outcomes of venous thrombosis (VTE) and hemorrhage were identified by validated algorithms using relevant diagnoses and billing codes. Overlap-weighted cause-specific Cox proportional hazard models were used to examine the association of direct oral anticoagulants (DOAC) on the 90-day risk of VTE and hemorrhage compared with low-molecular-weight heparin (LMWH). A total of 27 645 patients were prescribed DOAC (N = 22 943) or LMWH (N = 4702) after arthroplasty. Rivaroxaban was the predominant DOAC (94.5%), while LMWH mainly included enoxaparin (67%) and dalteparin (31.5%). DOAC users had higher eGFRs, fewer co-morbidities, and surgery in more recent years compared to LMWH users. After weighing, DOAC (compared with LMWH) was associated with a lower risk of VTE (DOAC: 1.5% vs. LMWH: 2.1%, weighted hazard ratio [HR] 0.75, 95% confidence interval [CI] 0.59-0.94) and a higher risk of hemorrhage (DOAC: 1.3% vs. LMWH: 1.0%, weighted HR 1.44, 95% CI 1.04-1.99). Additional analyses including a more stringent VTE defining algorithm, different eGFR cut-offs, and limiting to rivaroxaban and enoxaparin showed consistent findings. Among elderly adults with CKD, DOAC was associated with a lower VTE risk and a higher hemorrhage risk compared to LMWH following hip or knee arthroplasty.

A Health Survey-Based Prediction Equation for Incident CKD.

BACKGROUND: Prediction tools that incorporate self-reported health information could increase CKD awareness, identify modifiable lifestyle risk factors, and prevent disease. We developed and validated a survey-based prediction equation to identify individuals at risk for incident CKD (eGFR <60 ml/min per 1.73 m2), with and without a baseline eGFR. METHODS: A cohort of adults with an eGFR ≥70 ml/min per 1.73 m2 from Ontario, Canada, who completed a comprehensive general population health survey between 2000 and 2015 were included (n=22,200). Prediction equations included demographics (age, sex), comorbidities, lifestyle factors, diet, and mood. Models with and without baseline eGFR were derived and externally validated in the UK Biobank (n=15,522). New-onset CKD (eGFR <60 ml/min per 1.73 m2) with ≤8 years of follow-up was the primary outcome. RESULTS: Among Ontario individuals (mean age, 55 years; 58% women; baseline eGFR, 95 (SD 15) ml/min per 1.73 m2), new-onset CKD occurred in 1981 (9%) during a median follow-up time of 4.2 years. The final models included lifestyle factors (smoking, alcohol, physical activity) and comorbid illnesses (diabetes, hypertension, cancer). The model was discriminating in individuals with and without a baseline eGFR measure (5-year c-statistic with baseline eGFR: 83.5, 95% confidence interval [CI], 82.2 to 84.9; without: 81.0, 95% CI, 79.8 to 82.4) and well calibrated. In external validation, the 5-year c-statistic was 78.1 (95% CI, 74.2 to 82.0) and 66.0 (95% CI, 61.6 to 70.4), with and without baseline eGFR, respectively, and maintained calibration. CONCLUSIONS: Self-reported lifestyle and health behavior information from health surveys may aid in predicting incident CKD. PODCAST: This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast.aspx?p=CJASN&e=2023_01_10_CJN05650522.mp3.

Association of Higher-Dose Fluoroquinolone Therapy With Serious Adverse Events in Older Adults With Advanced Chronic Kidney Disease.

Importance: Population-based data are needed to inform the safe prescribing of fluoroquinolone antibiotics to patients with advanced chronic kidney disease (CKD). Objective: To quantify the 14-day risk of a hospital visit with nervous system and/or psychiatric disorders, hypoglycemia, or a collagen-associated event in patients with advanced CKD newly prescribed a fluoroquinolone at a higher vs a lower dose. Design, Setting, and Participants: This population-based cohort study in Ontario, Canada (January 1, 2008, to March 17, 2020) used linked health care data to identify new users of fluoroquinolone antibiotics. Participants included adults 66 years or older with advanced CKD (an estimated glomerular filtration rate [eGFR] <30 mL/min/1.73 m2 but not receiving dialysis). Data analysis was performed from January 1 to April 30, 2021. Exposures: A new prescription for a higher-dose fluoroquinolone (ciprofloxacin, 501-1000 mg/d; levofloxacin, 501-750 mg/d; or norfloxacin, 401-800 mg/d) vs a lower-dose fluoroquinolone (ciprofloxacin, 500 mg/d; levofloxacin, 250-500 mg/d; or norfloxacin, 400 mg/d). Main Outcomes and Measure: The primary outcome was the 14-day risk of a hospital visit with nervous system and/or psychiatric disorders, hypoglycemia, or a collagen-associated event. Secondary outcomes included a hospital visit with sepsis, retinal detachment or other tendinopathies, all-cause hospitalization, all-cause mortality, and sudden cardiac death. Inverse probability of treatment weighting on the propensity score was used to balance comparison groups on baseline health. Weighted risk ratios and risk differences were obtained using modified Poisson regression and binomial regression, respectively. Results: Of 11 917 patients (median age, 83 years [IQR, 77-89 years]; 7438 women [62.4%]; median eGFR, 25 [IQR, 21-28] mL/min/1.73 m2) included in the analysis, 5482 (46.0%) received a higher-dose and 6435 (54.0%) received a lower-dose fluoroquinolone. After weighting, the primary composite outcome-a hospital visit with nervous system and/or psychiatric disorders, hypoglycemia, or a collagen-associated event-occurred in 68 of 5482 patients (1.2%) treated with a higher-dose fluoroquinolone and in 47 of 5516 (0.9%) treated with a lower-dose fluoroquinolone (weighted risk ratio, 1.45 [95% CI, 1.01-2.08]; weighted risk difference, 0.39% [95% CI, 0.01%-0.76%]). The risk of sepsis, retinal detachment, all-cause hospitalization, all-cause mortality, and sudden cardiac death did not differ significantly between groups. Conclusions and Relevance: These findings suggest that older patients with advanced CKD who were prescribed a fluoroquinolone at a higher-than-recommended dose were significantly more likely to experience the composite outcome of a hospital visit with nervous system and/or psychiatric disorders, hypoglycemia, or a collagen-associated event, although the absolute risk of these events was less than 2%.

Impact of Donation Physicians on Deceased Organ Donation: A Systematic Review.

Background: An emerging strategy to increase deceased organ donation is to use dedicated donation physicians to champion organ donation. We sought to conduct a systematic review of the effectiveness of donation physicians in improving organ donation outcomes. Objective: A systematic review was conducted following Cochrane principles. MEDLINE, Embase, and CINHAL databases were searched from inception to March 26, 2020. Methods: Quantitative studies examining the effects of donation physicians on all deceased organ donation outcomes were considered for inclusion. Review articles, editorials and opinion articles, and case studies were excluded. Study selection was completed independently by 2 team members; all discrepancies were resolved by consensus. Two team members independently extracted data from studies. Results: A total of 1017 studies were screened, and 12 met inclusion criteria. Included studies were published between 1994 and 2019. Half used an interrupted time series design (n = 6; 50%), 3 (25%) were cohort studies, and 3 (25%) used a before-and-after study design. Outcomes (reported in greater than 50% of included articles) included consent/refusal rate (n = 8; 67%), number of potential donors (n = 7; 58%), and number of actual donors (n = 7; 58%). Across studies and design types, there was an increase in potential organ donors ranging from 8% to 143% (Mdn = 33%), an increase in actual organ donors from 15% to 113% (Mdn = 27%), an increase in donor consent rate from -3% to 258% (Mdn = 12%), and an increase in deceased donor transplants from 13% to 24% (Mdn = 19%) following the introduction of donation physicians. Conclusions: Donation physicians have the potential to significantly improve deceased organ donation. Further implementation and evaluation of donation physician programs is warranted. However, implementation should be undertaken with a clear plan for a methodologically rigorous evaluation of outcomes.

Contexte: Le recours à des médecins responsables du don d'organes est une stratégie émergente qui vise à favoriser les dons d'organes après le décès. Nous avons voulu vérifier son efficacité par le biais d'une revue systématique. Sources: La revue systématique a été réalisée conformément aux principes de Cochrane. Les bases de données MEDLINE, Embase et CINHAL ont fait l'objet d'une recherche depuis leur création jusqu'au 26 mars 2020. Méthodologie: Ont été sélectionnées les études quantitatives mesurant l'effet des médecins responsables du don d'organes sur tous les résultats de dons d'organes provenant de personnes décédées. Les articles de revue, éditoriaux, articles d'opinion et études de cas ont été exclus. Deux membres de l'équipe ont procédé de façon indépendante à la sélection des études et à l'extraction des données; les divergences ont été résolues par consensus. Résultats: Des 1 017 études sélectionnées, 12 satisfaisaient aux critères d'inclusion. Les études incluses avaient été publiées entre 1994 et 2019. La moitié des études incluses avait utilisé un modèle de série chronologique interrompu (n = 6; 50 %), trois (25 %) étaient des études de cohorte et trois (25 %) avaient une conception d'étude « avant-après ¼. Les résultats (rapportés dans plus de 50 % des articles inclus) comprenaient le taux de consentement/refus (n = 8; 67 %), le nombre de donneurs potentiels (n = 7; 58 %) et le nombre de donneurs réels (n = 7; 58 %). Après l'introduction de médecins responsables du don d'organes, selon l'étude et le type de conception, on a observé une augmentation allant de 8 à 143 % (augmentation médiane [AM]: 33 %) du nombre de donneurs potentiels, de 15 à 113 % (AM: 27 %) du nombre réel de donneurs, de -3 à 258 % (AM: 12 %) du taux de consentement et de 13 à 24 % (AM: 19 %) du nombre de transplantations d'organes provenant de donneurs décédés. Conclusion: L'introduction de médecins responsables du don d'organes est susceptible d'améliorer significativement le don d'organes après le décès. Il est justifié de poursuivre la mise en œuvre et l'évaluation des programmes intégrant des médecins responsables du don d'organes. La mise en œuvre doit cependant être entreprise avec un plan clair visant une évaluation méthodique et rigoureuse des résultats.

Effectiveness of first, second, and third COVID-19 vaccine doses in solid organ transplant recipients: A population-based cohort study from Canada.

Limited data exists on the effectiveness of a third COVID-19 vaccine dose in solid organ transplant recipients. We conducted a population-based cohort study using linked healthcare databases from Ontario, Canada to answer this question. We included solid organ transplant recipients (n = 12,842) as of December 14, 2020, with follow-up until November 28, 2021. We used an extended Cox proportional hazards model with vaccination status, including BNT162b2, mRNA-1273, and ChAdOx1 vaccines, modeled as a time-dependent exposure. Individuals started in the unvaccinated category (reference) and could contribute person-time to first, second, and third doses. Over a median follow-up of 349 days, 12.7% (n = 1632) remained unvaccinated, 54.1% (n = 6953) received 3 doses, and 488 (3.8%) tested positive for SARS-CoV-2 (of which 260 [53.3%] had a clinically important outcome [i.e., hospitalization or death]). Adjusted vaccine effectiveness against infection was 31% (95% CI: 2, 51%), 46% (95% CI: 21, 63%), and 72% (95% CI: 43, 86%) for one, two, and three doses. Vaccine effectiveness against clinically important outcomes was 38% (95% CI: 4, 61%), 54% (95% CI: 23, 73%), and 67% (95% CI: 11, 87%). Vaccine effectiveness in solid organ transplant recipients is lower than the general population, however, vaccine effectiveness improved following a third dose.

Information transmission in recurrent networks: Consequences of network noise for synchronous and asynchronous signal encoding.

Information about natural time-dependent stimuli encoded by the sensory periphery or communication between cortical networks may span a large frequency range or be localized to a smaller frequency band. Biological systems have been shown to multiplex such disparate broadband and narrow-band signals and then discriminate them in later populations by employing either an integration (low-pass) or coincidence detection (bandpass) encoding strategy. Analytical expressions have been developed for both encoding methods in feedforward populations of uncoupled neurons and confirm that the integration of a population's output low-pass filters the information, whereas synchronous output encodes less information overall and retains signal information in a selected frequency band. The present study extends the theory to recurrent networks and shows that recurrence may sharpen the synchronous bandpass filter. The frequency of the pass band is significantly influenced by the synaptic strengths, especially for inhibition-dominated networks. Synchronous information transfer is also increased when network models take into account heterogeneity that arises from the stochastic distribution of the synaptic weights.

Critical current for giant Fano factor in neural models with bistable firing dynamics and implications for signal transmission.

Bistability in the firing rate is a prominent feature in different types of neurons as well as in neural networks. We show that for a constant input below a critical value, such bistability can lead to a giant spike-count diffusion. We study the transmission of a periodic signal and demonstrate that close to the critical bias current, the signal-to-noise ratio suffers a sharp increase, an effect that can be traced back to the giant diffusion and large Fano factor.

Clinical evaluation and ancillary testing for the diagnosis of death by neurologic criteria: a cross-sectional survey of Canadian intensivists.

PURPOSE: Trust in the deceased organ donation process relies on the expectation that the diagnosis of death by neurologic criteria (DNC) is accurate and reliable. The objective of this study was to assess the perceptions and approaches to DNC diagnosis among Canadian intensivists. METHODS: We conducted a self-administered, online, cross-sectional survey of Canadian intensivists. Our sampling frame included all intensivists practicing in Canadian institutions. Results are reported using descriptive statistics. RESULTS: Among 550 identified intensivists, 249 (45%) completed the survey. Respondents indicated they would be comfortable diagnosing DNC based on clinical criteria alone in cases where there is movement in response to stimulation (119/248; 48%); inability to evaluate upper/lower extremity responses (84/249; 34%); spontaneous peripheral movement (76/249; 31%); inability to evaluate both oculocephalic and oculo-caloric reflexes (40/249; 16%); presence of high cervical spinal cord injury (40/249; 16%); and within 24 hr of hypoxemic-ischemic brain injury (38/247; 15%). Most respondents agreed that an ancillary test should always be conducted when a complete clinical evaluation is impossible (225/241; 93%); when there is possibility of a residual sedative effect (216/242; 89%); when the mechanism for brain injury is unclear (172/241; 71%); and if isolated brainstem injury is suspected (142/242; 59%). Sixty-six percent (158/241) believed that ancillary tests are sensitive and 55% (132/241) that they are specific for DNC. Respondents considered the following ancillary tests useful for DNC: four-vessel conventional angiography (211/241; 88%), nuclear imaging (179/240; 75%), computed tomography (CT) angiography (156/240; 65%), and CT perfusion (134/240; 56%). CONCLUSION: There is variability in perceptions and approaches to DNC diagnosis among Canadian intensivists, and some practices are inconsistent with national recommendations.

RéSUMé: OBJECTIF: La confiance dans le processus de don d'organes de donneurs décédés repose sur l'attente que le diagnostic de décès déterminé par des critères neurologiques (DDN) soit précis et fiable. L'objectif de cette étude était d'évaluer les perceptions et les approches du diagnostic de DDN chez les intensivistes canadiens. MéTHODE: Nous avons mené un sondage transversal auto-administré et en ligne auprès des intensivistes canadiens. Notre base d'échantillonnage comprenait tous les intensivistes exerçant dans des établissements canadiens. Les résultats sont présentés à l'aide de statistiques descriptives. RéSULTATS: Parmi les 550 intensivistes identifiés, 249 (45 %) ont répondu au sondage. Les répondants ont indiqué qu'ils seraient à l'aise de diagnostiquer un DDN en fonction de critères cliniques seulement dans les cas où il y a : un mouvement en réponse à une stimulation (119/248; 48 %); une incapacité à évaluer les réponses des membres supérieurs et inférieurs (84/249; 34 %); un mouvement périphérique spontané (76/249; 31 %); une incapacité à évaluer à la fois les réflexes oculo-céphaliques et vestibulo-oculaires (40/249; 16 %); la présence de lésions médullaires cervicales hautes (40/249; 16 %); et dans les 24 heures suivant une lésion cérébrale hypoxémique-ischémique (38/247; 15 %). La plupart des répondants étaient d'accord pour dire qu'un test auxiliaire devrait toujours être réalisé lorsqu'une évaluation clinique complète est impossible (225/241; 93 %); lorsqu'il y a possibilité d'un effet sédatif résiduel (216/242; 89 %); lorsque le mécanisme de la lésion cérébrale n'est pas clair (172/241; 71 %); et si une lésion isolée du tronc cérébral est suspectée (142/242; 59 %). Soixante-six pour cent (158/241) des répondants étaient d'avis que les tests auxiliaires étaient sensibles et 55 % (132/241) qu'ils étaient spécifiques pour le DDN. Les répondants ont jugé utiles les tests auxiliaires suivants pour le DDN : l'angiographie conventionnelle des quatre vaisseaux (211/241; 88 %), l'imagerie nucléaire (179/240; 75 %), l'angiographie par tomodensitométrie (TDM) (156/240; 65 %) et la perfusion en TDM (134/240; 56 %). CONCLUSION: Les perceptions et les approches du diagnostic de DDN varient parmi les intensivistes canadiens, et certaines pratiques ne sont pas conformes aux recommandations nationales.

Pre-transplant maintenance dialysis duration and outcomes after kidney transplantation: A multicenter population-based cohort study.

The association between pre-transplant dialysis duration and post-transplant outcomes may vary by the population and endpoints studied. We conducted a population-based cohort study using linked healthcare databases from Ontario, Canada including kidney transplant recipients (n = 4461) from 2004 to 2014. Our primary outcome was total graft failure (i.e., death, return to dialysis, or pre-emptive re-transplant). Secondary outcomes included death-censored graft failure, death with graft function, mortality, hospitalization for cardiovascular events, hospitalization for infection, and hospital readmission. We presented results by pre-transplant dialysis duration (pre-emptive transplant, and .01-1.43, 1.44-2.64, 2.65-4.25, 4.26-6.45, and 6.46-36.5 years, for quintiles 1-5). After adjusting for clinical characteristics, pre-emptive transplantation was associated with a lower rate of total graft failure (adjusted hazard ratio [aHR] .68, 95% CI: .46, .99), while quintile 4 was associated with a higher rate (aHR 1.31, 95% CI: 1.01, 1.71), when compared to quintile 1. There was no significant relationship between dialysis duration and death-censored graft failure, cardiovascular events, or hospital readmission. For death with graft function and mortality, quintiles 3-5 had a significantly higher aHR compared to quintile 1, while for infection, quintiles 2-5 had a higher aHR. Longer time on dialysis was associated with an increased rate of several adverse post-transplant outcomes.

Risk Factors and Outcomes of Early Hospital Readmission in Canadian Kidney Transplant Recipients: A Population-Based Multi-Center Cohort Study.

BACKGROUND: Early hospital readmissions (EHRs) occur commonly in kidney transplant recipients. Conflicting evidence exists regarding risk factors and outcomes of EHRs. OBJECTIVE: To determine risk factors and outcomes associated with EHRs (ie, hospitalization within 30 days of discharge from transplant hospitalization) in kidney transplant recipients. DESIGN: Population-based cohort study using linked, administrative health care databases. SETTING: Ontario, Canada. PATIENTS: We included 5437 kidney transplant recipients from 2002 to 2015. MEASUREMENTS: Risk factors and outcomes associated with EHRs. We assessed donor, recipient, and transplant risk factors. We also assessed the following outcomes: total graft failure, death-censored graft failure, death with a functioning graft, mortality, and late hospital readmission. METHODS: We used multivariable logistic regression to examine the association of each risk factor and the odds of EHR. To examine the relationship between EHR status (yes vs no [reference]) and the outcomes associated with EHR (eg, total graft failure), we used a multivariable Cox proportional hazards model. RESULTS: In all, 1128 kidney transplant recipients (20.7%) experienced an EHR. We found the following risk factors were associated with an increased risk of EHR: older recipient age, lower income quintile, several comorbidities, longer hospitalization for initial kidney transplant, and older donor age. After adjusting for clinical characteristics, compared to recipients without an EHR, recipients with an EHR had an increased risk of total graft failure (adjusted hazard ratio [aHR]: 1.46, 95% CI: 1.29, 1.65), death-censored graft failure (aHR: 1.62, 95% CI: 1.36, 1.94), death with graft function (aHR: 1.34, 95% CI: 1.13, 1.59), mortality (aHR: 1.41, 95% CI: 1.22, 1.63), and late hospital readmission in the first 0.5 years of follow-up (eg, 0 to <0.25 years: aHR: 2.11, 95% CI: 1.85, 2.40). LIMITATIONS: We were not able to identify which readmissions could have been preventable and there is a potential for residual confounding. CONCLUSIONS: Results can be used to identify kidney transplant recipients at risk of EHR and emphasize the need for interventions to reduce the risk of EHRs. TRIAL REGISTRATION: This is not applicable as this is a population-based cohort study and not a clinical trial.

CONTEXTE: Les réadmissions précoces à l'hôpital (RPH) sont fréquentes chez les receveurs d'une greffe rénale. Les données sur les facteurs de risque d'une RPH et sur les résultats qui y sont associés restent toutefois contradictoires. OBJECTIF: Définir les facteurs de risque et les effets associés à une RPH (soit une hospitalization dans les 30 jours suivant la sortie de l'hôpital après la transplantation) chez les receveurs de greffe rénale. TYPE D'ÉTUDE: Étude de cohorte représentative d'une population, réalisée à partir des bases de données administratives en santé. CADRE: Ontario, Canada. SUJETS: Ont été inclus 5 437 adultes receveurs d'une greffe rénale entre 2002 et 2015. MESURES: Les facteurs de risque et les résultats associés à une RPH. Nous avons évalué les facteurs de risque du donneur, du receveur et de la transplantation. Nous avons également évalué les résultats suivants : l'échec du greffon, l'échec du greffon censuré par le décès, le décès avec un greffon fonctionnel, la mortalité et les réadmissions tardives. MÉTHODOLOGIE: Nous avons utilisé la régression logistique multivariée pour examiner l'association de chaque facteur de risque et les probabilités de RPH. Un modèle multivarié des risques proportionnels de Cox a par ailleurs servi à examiner la relation entre le statut des RPH (oui vs non [référence]) et les résultats associés à celles-ci (p. ex., l'échec de la greffe). RÉSULTATS: Dans la cohorte étudiée, 1 128 receveurs d'une greffe rénale (20,7 %) ont été réadmis précocement à l'hôpital. Les facteurs de risque suivants ont été associés à un risque accru de RPH : âge plus avancé du receveur, provenance d'un quartier au quintile de revenu inférieur, présence de plusieurs comorbidités, hospitalization initiale plus longue pour la transplantation rénale et âge plus avancé du donneur. Après ajustement pour les caractéristiques cliniques, par rapport aux receveurs de greffe qui n'avaient pas été réadmis précocement, les patients avec une RPH présentaient un risque accru d'échec du greffon (risque relatif corrigé [RRc] : 1,46; IC 95 % : 1,29-1,65), d'échec du greffon censuré par le décès (RRc: 1,62; IC 95 % : 1,36-1,94), de décès avec un greffon fonctionnel (RRc: 1,34; IC 95 % : 1,13-1,59), de mortalité (RRc: 1,41; IC 95 % : 1,22-1,63) et de réadmission tardive au cours des premiers six mois de suivi (p. ex., entre 0 et moins de 0,25 an de suivi, le RRc était de 2,11; [IC 95 % : 1,85-2,40]). LIMITES: Nous n'avons pas été en mesure d'identifier les réadmissions qui auraient pu être prévenues et il existe un risque de facteurs de confusion résiduels. CONCLUSION: Ces résultats peuvent être employés pour identifier les receveurs d'une greffe rénale susceptibles d'être réadmis rapidement à l'hôpital. Ces résultats soulignent en outre la nécessité d'interventions pour réduire le risque de RPH. ENREGISTREMENT DE L'ESSAI: Sans objet puisqu'il s'agit d'une étude de cohorte basée sur la population et non d'un essai clinique.

Comparison of All-Cause Mortality Between Canadian Kidney Transplant Recipients and Patients With Cancer: A Population-Based Cohort Study.

BACKGROUND: Understanding rates of mortality in kidney transplant recipients relative to other common diseases can enhance our understanding of the mortality burden in kidney transplant recipients. OBJECTIVE: To compare the survival probability in Canadian female and male kidney transplant recipients with patients with common cancers (female: breast, colorectal, lung, or pancreas; male: prostate, colorectal, lung, or pancreas) in a contemporary population. DESIGN: Population-based cohort study using linked administrative health care databases. SETTING: Ontario, Canada. PATIENTS: A total of 6888 incident kidney transplant recipients (median age was 50 and 51 years in females and males, respectively) and a total of 532 452 incident patients with cancer (median age range 60 to 72 years across cancer types) from 1997 to 2015. MEASUREMENTS: All-cause mortality. METHODS: The survival of study participants was described using the Kaplan-Meier product limit estimator. The rate of survival was compared between kidney transplant recipients and patients with cancer using extended Cox regression with a Heaviside function. RESULTS: Kidney transplant recipients had a higher survival probability compared with all cancer types. For example, male kidney transplant recipients had a 5-year survival probability of 89.6% (95% confidence interval [CI]: 88.6%-90.5%) compared with 83.3% (95% CI: 83.1%-83.5%) in patients with prostate cancer, and 14.0% (95% CI: 13.7%-14.3%), 56.1% (95% CI: 55.7%-56.5%), and 9.1% (95% CI: 8.5%-9.7%) in patients with lung, colorectal, and pancreas cancer, respectively. After presenting survival probabilities by age at cohort entry and after adjusting for clinical characteristics, similar results were found with a few exceptions. Unlike the unadjusted analysis, in the adjusted analysis males with prostate cancer had a significantly higher survival compared with kidney transplant recipients and females with breast cancer had higher survival compared with kidney transplant recipients at 2+ years of follow-up. In a subpopulation of the cohort who had information available on cancer stage (ie, stages 1-4), we generally found similar results to our primary analysis with kidney transplant recipients having a higher survival probability compared with each cancer stage. However, female kidney transplant recipients had a lower survival probability compared with females with stage 1 breast cancer, whereas male kidney transplant recipients had a lower survival probability compared with males with stage 1 to 3 prostate cancer. LIMITATIONS: External generalizability, residual confounding, and cancer stage could only be provided for a subpopulation. CONCLUSION: Mortality in kidney transplant recipients is lower than in patients with several cancer types. These results improve our understanding of the mortality burden in this population and reaffirm kidney transplantation as a good treatment option for end-stage kidney disease but also highlight the continuing need to improve posttransplant survival. TRIAL REGISTRATION: This is not applicable as this is a population-based cohort study and not a clinical trial.

CONTEXTE: La comparaison du taux de mortalité des receveurs d'une greffe rénale par rapport à celui des patients atteints d'autres maladies courantes pourrait améliorer notre compréhension du fardeau que cela représente chez les transplantés rénaux. OBJECTIFS: Comparer la probabilité de survie des transplantés rénaux canadiens, femmes et hommes, à celle de patients atteints de cancers fréquents (femmes : sein, colorectal poumons ou pancréas; hommes : prostate, colorectal, poumons ou pancréas) dans une population contemporaine. TYPE D'ÉTUDE: Étude de cohorte représentative d'une population réalisée à partir des données administratives en santé. CADRE: Ontario, Canada. SUJETS: L'étude porte sur 6 888 transplantés du rein incidents (âge médian : 50 ans [femmes] et 51 ans [hommes]) et un total de 532 452 patients atteints d'un cancer (âge médian : 60 à 72 ans pour tous les types de cancers) répertoriés entre 1997 et 2015. MESURES: Mortalité toutes causes confondues. MÉTHODOLOGIE: La survie des patients a été décrite à l'aide de l'estimateur produit-limite de Kaplan-Meier. Une régression étendue de Cox avec une distribution de Heaviside a servi à comparer les taux survie des transplantés rénaux et des patients atteints d'un cancer. RÉSULTATS: La probabilité de survie des transplantés Renaud s'est avérée plus élevée que celle observée pour tous les types de cancer. À titre d'exemple, la probabilité de survie des hommes transplantés était de 89,6 % (IC à 95 % : 88,6-56,9 %) après 5 ans alors qu'elle s'établissait à 83,3 % (IC 95 % : 83,1-83,5 %) chez les patients atteints d'un cancer de la prostate et à 14,0 % (IC à 95 % : 13,7-14,3 %), 56,1 % (IC 95 % : 55,7-56,5 %) et 9,1 % (IC 95 % : 8,5-9,7 %) chez les patients atteints respectivement d'un cancer du poumon, colorectal et du pancréas. Des résultats similaires, à quelques exceptions près, ont été observés après une présentation des probabilités de survie selon l'âge à l'inclusion dans la cohorte et après correction en fonction des caractéristiques cliniques. Dans l'analyse corrigée, contrairement à l'analyse non corrigée, la probabilité de survie des hommes atteints d'un cancer de la prostate et celle des femmes atteintes d'un cancer du sein étaient significativement plus élevées que celle des receveurs d'une greffe rénale après plus de deux ans de suivi. Une sous-population issue de la cohorte de patients disposant d'informations sur le stade du cancer (stades 1 à 4) a montré des résultats généralement similaires à ceux de notre analyse primaire; les transplantés rénaux montrant une probabilité de survie plus élevée comparativement à chaque stade de cancer. Cependant, les receveuses d'une greffe rénale présentaient une probabilité de survie plus faible que les femmes atteintes d'un cancer du sein de stade 1; un résultat similaire a été observé chez les receveurs d'un rein comparativement aux hommes atteints d'un cancer de la prostate de stade 1 à 3. LIMITES: Généralisabilité externe; facteurs de confusion résiduels; stade du cancer connu pour une sous-population uniquement. CONCLUSION: Le taux de mortalité chez les receveurs d'un greffe rénale est inférieur à celui des patients atteints de plusieurs types de cancer. Ces résultats permettent de mieux comprendre le fardeau que représente la mortalité dans cette population et de réaffirmer la transplantation rénale comme option de traitement valide pour l'insuffisance rénale terminale. Ces résultats rappellent également qu'il demeure indispensable d'améliorer les taux de survie post-transplantation. ENREGISTREMENT DE L'ESSAI: Sans objet. Il s'agit d'une étude de cohorte basée sur une population et non d'un essai clinique.

Commentary on the KDIGO 2021 Clinical Practice Guideline for the Management of Blood Pressure in CKD.

PURPOSE OF REVIEW: To summarize and explain the new guideline on blood pressure (BP) management in chronic kidney disease (CKD) published by Kidney Disease: Improving Global Outcomes (KDIGO), an independent global nonprofit organization which develops and implements evidence-based clinical practice guidelines in kidney disease. KDIGO issued its first clinical practice guideline for the Management of Blood Pressure (BP) in Chronic Kidney Disease (CKD) for patients not receiving dialysis in 2012 and now updated the guideline in 2021. RECENT FINDINGS: Recommendations in this update were developed based on systematic literature reviews and appraisal of the quality of the evidence and strength of recommendation following the "Grading of Recommendations Assessment, Development and Evaluation" (GRADE) approach. The updated guideline includes five chapters covering BP measurement techniques, lifestyle interventions for lowering BP, and management of BP in three target populations, namely adults (with and without diabetes), kidney transplant recipients, and children. A dedicated chapter on BP measurement emphasizing standardized preparation and measurement protocols for office BP measurement is a new addition, following protocols used in large randomized trials of BP targets with pivotal clinical outcomes. Based on the available evidence, and in particular in the CKD subgroup of the SPRINT trial, the 2021 guideline suggests a systolic BP target of <120 mm Hg, based on standardized measurements, for most individuals with CKD not receiving dialysis, with the exception of kidney transplant recipients and children. This recommendation is strictly contingent on the measurement of BP using standardized office readings and not routine office readings.

Management of Blood Pressure in Patients With Chronic Kidney Disease Not Receiving Dialysis: Synopsis of the 2021 KDIGO Clinical Practice Guideline.

DESCRIPTION: The Kidney Disease: Improving Global Outcomes (KDIGO) 2021 clinical practice guideline for the management of blood pressure (BP) in patients with chronic kidney disease (CKD) not receiving dialysis is an update of the KDIGO 2012 guideline on the same topic and reflects new evidence on the risks and benefits of BP-lowering therapy among patients with CKD. It is intended to support shared decision making by health care professionals working with patients with CKD worldwide. This article is a synopsis of the full guideline. METHODS: The KDIGO leadership commissioned 2 co-chairs to convene an international Work Group of researchers and clinicians. After a Controversies Conference in September 2017, the Work Group defined the scope of the evidence review, which was undertaken by an evidence review team between October 2017 and April 2020. Evidence reviews were done according to the Cochrane Handbook. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach was used to guide the development of the recommendations and rate the strength and quality of the evidence. Practice points were included to provide guidance when evidence was insufficient to make a graded recommendation. The guideline was revised after public consultation between January and March 2020. RECOMMENDATIONS: The updated guideline comprises 11 recommendations and 20 practice points. This synopsis summarizes key recommendations pertinent to the diagnosis and management of high BP in adults with CKD, excluding those receiving kidney replacement therapy. In particular, the synopsis focuses on recommendations for standardized BP measurement and a target systolic BP of less than 120 mm Hg, because these recommendations differ from some other guidelines.

Recurrence-mediated suprathreshold stochastic resonance.

It has previously been shown that the encoding of time-dependent signals by feedforward networks (FFNs) of processing units exhibits suprathreshold stochastic resonance (SSR), which is an optimal signal transmission for a finite level of independent, individual stochasticity in the single units. In this study, a recurrent spiking network is simulated to demonstrate that SSR can be also caused by network noise in place of intrinsic noise. The level of autonomously generated fluctuations in the network can be controlled by the strength of synapses, and hence the coding fraction (our measure of information transmission) exhibits a maximum as a function of the synaptic coupling strength. The presence of a coding peak at an optimal coupling strength is robust over a wide range of individual, network, and signal parameters, although the optimal strength and peak magnitude depend on the parameter being varied. We also perform control experiments with an FFN illustrating that the optimized coding fraction is due to the change in noise level and not from other effects entailed when changing the coupling strength. These results also indicate that the non-white (temporally correlated) network noise in general provides an extra boost to encoding performance compared to the FFN driven by intrinsic white noise fluctuations.