Drug stewardship in chronic kidney disease to achieve effective and safe medication use.

People living with chronic kidney disease (CKD) often experience multimorbidity and require polypharmacy. Kidney dysfunction can also alter the pharmacokinetics and pharmacodynamics of medications, which can modify their risks and benefits; the extent of these changes is not well understood for all situations or medications. The principle of drug stewardship is aimed at maximizing medication safety and effectiveness in a population of patients through a variety of processes including medication reconciliation, medication selection, dose adjustment, monitoring for effectiveness and safety, and discontinuation (deprescribing) when no longer necessary. This Review is aimed at serving as a resource for achieving optimal drug stewardship for patients with CKD. We describe special considerations for medication use during pregnancy and lactation, during acute illness and in patients with cancer, as well as guidance for the responsible use of over-the-counter drugs, herbal remedies, supplements and sick-day rules. We also highlight inequities in medication access worldwide and suggest policies to improve access to quality and essential medications for all persons with CKD. Further strategies to promote drug stewardship include patient education and engagement, the use of digital health tools, shared decision-making and collaboration within interdisciplinary teams. Throughout, we position the person with CKD at the centre of all drug stewardship efforts.

Implementation of a One-Day Living Kidney Donor Assessment Clinic to Improve the Efficiency of the Living Kidney Donor Evaluation: Program Report.

Purpose of program: A key barrier to becoming a living kidney donor is an inefficient evaluation process, requiring more than 30 tests (eg, laboratory and diagnostic tests), questionnaires, and specialist consultations. Donor candidates make several trips to hospitals and clinics, and often spend months waiting for appointments and test results. The median evaluation time for a donor candidate in Ontario, Canada, is nearly 1 year. Longer wait times are associated with poorer outcomes for the kidney transplant recipient and higher health care costs. A shorter, more efficient donor evaluation process may help more patients with kidney failure receive a transplant, including a pre-emptive kidney transplant (ie, avoiding the need for dialysis). In this report, we describe the development of a quality improvement intervention to improve the efficiency, effectiveness, and patient-centeredness of the donor candidate evaluation process. We developed a One-Day Living Kidney Donor Assessment Clinic, a condensed clinic where interested donor candidates complete all testing and consultations within 1 day. Sources of information: The One-Day Living Kidney Donor Assessment Clinic was developed after performing a comprehensive review of the literature, receiving feedback from patients who have successfully donated, and meetings with transplant program leadership from St. Joseph's Healthcare Hamilton. A multistakeholder team was formed that included health care staff from nephrology, transplant surgery, radiology, cardiology, social work, nuclear medicine, and patients with the prior lived experience of kidney donation. In the planning stages, the team met regularly to determine the objectives of the clinic, criteria for participation, clinic schedule, patient flow, and clinic metrics. Methods: Donor candidates entered the One-Day Clinic if they completed initial laboratory testing and agreed to an expedited process. If additional testing was required, it was completed on a different day. Donor candidates were reviewed by the nephrologist, transplant surgeon, and donor coordinator approximately 2 weeks after the clinic for final approval. The team continues to meet regularly to review donor feedback, discuss challenges, and brainstorm solutions. Key findings: The One-Day Clinic was implemented in March 2019, and has now been running for 4 years, making iterative improvements through continuous patient and provider feedback. To date, we have evaluated more than 150 donor candidates in this clinic. Feedback from donors has been uniformly positive (98% of donors stated they were very satisfied with the clinic), with most noting that the clinic was efficient and minimally impacted work and family obligations. Hospital leadership, including the health care professionals from each participating department, continue to show support and collaborate to create a seamless experience for donor candidates attending the One-Day Clinic. Limitations: Clinic spots are limited, meaning some interested donor candidates may not be able to enter a One-Day Clinic the same month they come forward. Implications: This patient-centered quality improvement intervention is designed to improve the efficiency and experience of the living kidney donor evaluation, result in better outcomes for kidney transplant recipients, and potentially increase living donation. Our next step is to conduct a formal evaluation of the clinic, measuring qualitative feedback from health care professionals working in the clinic and donor candidates attending the clinic, and measuring key process and outcome measures in donor candidates who completed the one-day assessment compared with those who underwent the usual care assessment. This program evaluation will provide reliable, regionally relevant evidence that will inform transplant centers across the country as they consider incorporating a similar one-day assessment model.

Objectifs du programme: Devenir donneur de rein vivant est difficile, le principal obstacle étant le processus d'évaluation inefficace auquel les candidats doivent se soumettre. Ce processus comporte plus de 30 examens (p. ex. tests de laboratoire et tests diagnostiques), questionnaires et consultations avec des spécialistes. Les candidats donneurs font plusieurs visites dans les hôpitaux et cliniques, et passent souvent plusieurs mois à attendre des rendez-vous et des résultats de tests. En Ontario (Canada), le délai médian pour l'évaluation d'un candidat au don est de près d'un an. Les temps d'attente plus longs sont associés à de moins bons résultats pour les receveurs d'une greffe rénale, ainsi qu'à des coûts de soins de santé plus élevés. Un processus d'évaluation plus court et plus efficace des donneurs potentiels permettrait à un plus grand nombre de patients atteints d'insuffisance rénale de recevoir une greffe, y compris une greffe préventive (c.-à-d. permettant d'éviter la dialyse). Cet article décrit une intervention d'amélioration de la qualité visant à augmenter l'efficience, l'efficacité et la personnalisation du processus d'évaluation des candidats au don. Nous avons développé une clinique d'un jour pour l'évaluation des donneurs de reins vivants (One-Day Living Kidney Donor Assessment Clinic), soit une clinique condensée où les candidats passent tous les tests et consultent un spécialiste dans la même journée. Sources de l'information: La clinique d'un jour pour l'évaluation des donneurs de reins vivants a été développée à la suite d'un examen approfondi de la littérature, de la consultation des commentaires de patients ayant donné avec succès et de rencontres avec les dirigeants du programme de transplantation du St Joseph's Healthcare d'Hamilton. Une équipe multipartite a été formée; celle-ci réunit du personnel soignant en néphrologie, chirurgie de transplantation, radiologie, cardiologie, travail social et médecine nucléaire, ainsi que des patients ayant une expérience vécue du don de rein. L'équipe s'est réunie régulièrement pendant les étapes de planification pour déterminer les objectifs, les paramètres et le calendrier de la clinique, ainsi que les critères de participation et le flux de patients. Méthodologie: Les donneurs potentiels qui avaient complété les tests de laboratoire initiaux et qui acceptaient de se soumettre à un processus accéléré ont été évalués à la clinique d'un jour. Si des tests supplémentaires étaient nécessaires, ceux-ci étaient effectués un autre jour. Les candidats ont été rencontrés par le néphrologue, le chirurgien de transplantation et le coordonnateur des dons environ deux semaines après leur visite à la clinique pour l'approbation finale. L'équipe multipartite continue de se réunir régulièrement pour examiner les commentaires des donneurs, discuter des défis et trouver des solutions. Principaux résultats: La clinique d'un jour, mise sur pied en mars 2019, est en activité depuis quatre ans et permet des améliorations itératives grâce à la rétroaction continue des patients et des soignants. À ce jour, plus de 150 candidats au don ont été évalués à la clinique. Les commentaires des donneurs sont quasi unanimement positifs (98 % des candidats ont déclaré être très satisfaits de la clinique), la plupart soulignant l'efficacité de la clinique et les conséquences minimes du processus sur les obligations professionnelles et familiales. La direction de l'hôpital, tout comme les professionnels de la santé des services participants, continue d'appuyer la clinique d'un jour et de collaborer à la création d'une expérience fluide pour les donneurs potentiels qui la fréquentent. Limites: Les places à la clinique sont limitées; ainsi, certains candidats au don d'un rein vivant pourraient ne pas pouvoir être admis dans le mois où ils se présentent à la clinique. Conclusion: Cette intervention d'amélioration de la qualité axée sur les patients est conçue pour augmenter l'efficacité du processus d'évaluation et bonifier l'expérience des donneurs de rein vivants. Elle vise également à améliorer les résultats des receveurs d'une greffe rénale et, potentiellement, augmenter le don vivant. La prochaine étape sera une évaluation formelle de la clinique, c'est-à-dire la mesure de la rétroaction qualitative des professionnels de la santé qui y travaillent et des candidats au don qui la fréquentent, et l'analyse des processus clés et des résultats des candidats évalués à la clinique d'un jour par rapport à ceux qui suivent le processus d'évaluation habituel. Cette évaluation du programme fournira des données probantes fiables et propres à la région qui pourront informer les centres de transplantation de tout le pays qui envisagent d'intégrer un processus d'évaluation similaire.

Evaluation of the introduction of novel potassium binders in routine care; the Stockholm CREAtinine measurements (SCREAM) project.

BACKGROUND: The pharmacological management of hyperkalemia traditionally considered calcium or sodium polystyrene sulfonate and, since recently, the novel binders patiromer and sodium zirconium cyclosilicate. We evaluated their patterns of use, duration of treatment and relative effectiveness/safety in Swedish routine care. METHODS: Observational study of adults initiating therapy with sodium polystyrene sulfonate or a novel binder (sodium zirconium cyclosilicate or patiromer) in Stockholm 2019-2021. We quantified treatment duration by repeated dispensations, compared mean achieved potassium concentration within 60 days, and potential adverse events between treatments. RESULTS: A total of 1879 adults started treatment with sodium polystyrene sulfonate, and 147 with novel binders (n = 41 patiromer and n = 106 sodium zirconium cyclosilicate). Potassium at baseline for all treatments was 5.7 mmol/L. Sodium polystyrene sulfonate patients stayed on treatment a mean of 61 days (14% filled ≥3 consecutive prescriptions) compared to 109 days on treatment (49% filled ≥3 prescriptions) for novel binders. After 15 days of treatment, potassium similarly decreased to 4.6 (SD 0.6) and 4.8 (SD 0.6) mmol/L in the sodium polystyrene sulfonate and novel binder groups, respectively, and was maintained over the 60 days post-treatment. In multivariable regression, the odds ratio for novel binders (vs sodium polystyrene sulfonate) in reaching potassium ≤ 5.0 mmol/L after 15 days was 0.65 (95% CI 0.38-1.10) and after 60 days 0.89 (95% CI 0.45-1.76). Hypocalcemia, hypokalemia, and initiation of anti-diarrheal/constipation medications were the most-commonly detected adverse events. In multivariable analyses, the OR for these events did not differ between groups. CONCLUSION: We observed similar short-term effectiveness and safety for all potassium binders. However, treatment duration was longer for novel binders than for sodium polystyrene sulfonate.

A Simple Exercise Program for Patients With End-Stage Kidney Disease to Improve Strength and Quality of Life: Clinical Research Protocol.

Background: Most patients with end-stage kidney disease (ESKD) appreciate the importance of exercise and would like to increase their physical activity; however, they report a few key barriers, including (1) lack of physician advice to do so, (2) lack of safe and convenient programs (ie, appropriate for home or neighborhood), and (3) cost. Importantly, patients indicated in a previous survey that they would prefer an exercise program that improves muscle strength and symptoms, and are less interested in cardiovascular disease prevention. Objective: To test the feasibility of a simple, prescribed exercise program using Nordic walking poles in patients with ESKD treated with dialysis. Design: Randomized multicenter pilot trial of an exercise intervention that includes Nordic walking poles, personalized physician exercise prescriptions, pedometers, and access to exercise videos, compared with standard of care, in patients being treated with maintenance dialysis. Setting: Multicenter tertiary care centers in Canada. Patients: Ambulatory adult patients with ESKD treated with peritoneal dialysis or hemodialysis (HD) for at least 6 months at participating sites are potentially eligible. Inclusion criteria include ability to use Nordic walking poles (either de novo or in place of mobility aid) and to provide informed consent in English or in French. Exclusion criteria include (1) any absolute contraindication to exercise, (2) baseline step count >8000 steps/day, (3) planned living donor kidney transplant, and (4) participation in another interventional trial that may affect the results of this study. Methods: This is a randomized multicenter pilot trial of an exercise intervention that consists of a prescription to exercise using Nordic walking poles, a pedometer to track activity, and access to exercise videos, with the comparator of standard of care (dialysis unit staff encouragement to exercise) in patients being treated with maintenance dialysis. Randomization is concealed and uses a 1:1 ratio for group assignment. Our specific aims are to determine the feasibility of patient recruitment, adherence to the exercise program (verified by step counts), and efficacy of the intervention on patient-important outcomes that were assessed as a priority by patients in a prior survey-specifically strength, fatigue, and sleep. We record days spent in hospital and loss of independent living to inform sample size calculations for a definitive trial of exercise in patient with ESKD treated with dialysis. Adverse events are closely monitored. Outcomes: Primary: Our recruitment goal is 90 to 150 patients over 27 months; adherence success will be defined if >75% of randomized patients, excluding those who are transplanted or deceased, achieve >80% of their prescribed steps at 6 and 12 months. Secondary Efficacy Outcomes: (1) strength-hand grip strength and 5 times sit to stand, (2) energy-Short Form (SF)-36 vitality subscale, and (3) sleep-Pittsburg Sleep Quality Index will be assessed at baseline, 6, and 12 months. Results: Trial recruitment started before the COVID-19 pandemic and the pandemic led to many interruptions and delays. Online exercise Web sites and a tailored video were added to the protocol to encourage activity when participants were unable or reluctant to walk in public places. Limitations: This trial was designed to include ambulatory patients with ESKD and does not address the burden of disease in patients with very restricted mobility. Trial Registration: NCT03787589.

Contexte: La plupart des patients atteints d'insuffisance rénale terminale (IRT) comprennent l'importance de l'exercice physique et souhaitent augmenter leur niveau d'activité. Ils signalent toutefois quelques obstacles, notamment 1) le manque de conseils médicaux pour le faire; 2) le manque de programmes sécuritaires et faciles (c.-à-d. pouvant être suivis à la maison ou dans le quartier); et 3) les coûts. Il convient de noter que les patients avaient indiqué dans une enquête précédente préférer un programme d'exercices améliorant la force musculaire et les symptômes liés à la maladie, et être moins intéressés par la prévention des maladies cardiovasculaires. Objectif: Dans une population de patients atteints d'IRT traités par dialyse, tester la faisabilité d'un programme prescrit et simple à suivre d'exercices impliquant l'utilisation de bâtons de marche nordique. Conception: Essai pilote randomisé multicentrique mené chez des patients traités par dialyse d'entretien. L'essai compare les soins habituels à une intervention comprenant des exercices avec bâtons de marche nordique, un programme personnalisé prescrit par un médecin, un podomètre et l'accès à des vidéos d'exercices. Cadre: Plusieurs centres de soins tertiaires au Canada. Sujets: Tous les patients adultes ambulatoires atteints d'IRT traités par dialyse péritonéale ou hémodialyse depuis au moins 6 mois dans les sites participants sont potentiellement admissibles. Pour être inclus, les patients doivent pouvoir utiliser des bâtons de marche nordique (de novo ou en remplacement de l'aide à la mobilité) et fournir un consentement éclairé en anglais ou en français. Les critères d'exclusion sont : 1) toute contre-indication absolue à l'exercice; 2) le fait de marcher déjà au moins 8 000 pas/jour; 3) avoir une transplantation rénale d'un donneur vivant prévue; 4) la participation à un autre essai interventionnel susceptible d'affecter les résultats de la présente étude. Méthodologie: Il s'agit d'un essai pilote randomisé multicentrique examinant une intervention en matière d'activité physique. L'intervention consiste en une prescription d'activité physique à l'aide de bâtons de marche nordique, elle donne accès à un podomètre pour suivre l'activité, ainsi qu'à des vidéos d'exercices; le comparateur est la norme de soins (encouragement par le personnel de l'unité de dialyse à pratiquer une activité physique) pour les patients traités par dialyse d'entretien. La randomisation est masquée et utilise un ratio de 1:1 pour l'affectation aux groupes. Nous examinons la faisabilité du recrutement des patients, l'observance du programme d'exercices (vérifiée par le nombre de pas) et l'efficacité de l'intervention sur les résultats de santé ayant été jugés comme importants et prioritaires par les patients dans une enquête précédente ­ plus précisément la force, la fatigue et le sommeil. Nous enregistrons le nombre de jours passés à l'hôpital et la perte de vie autonome afin d'éclairer les calculs de la taille de l'échantillon d'un essai définitif qui portera sur l'activité physique en contexte d'HD. Les événements indésirables sont étroitement surveillés. Mesures: Primaires : nous souhaitons recruter 90 à 150 patients sur une période de 27 mois; l'observance sera jugée comme un succès si plus de 75 % des patients randomisés (excluant les patients transplantés ou décédés) atteignent plus de 80 % de leur prescription de nombres de pas/jour après 6 et 12 mois. Paramètres secondaires d'efficacité : 1) Force ­ mesure de la force de préhension et 5 fois l'exercice de se lever d'une position assise; 2) Énergie ­ sous-échelle du test de vitalité SF-36; et 3) Sommeil ­ mesure de l'Indice de la qualité du sommeil Pittsburg à l'inclusion et après 6 mois et 12 mois. Résultats: Le recrutement s'est amorcé avant la pandémie de COVID-19, puis celle-ci a entraîné de nombreuses interruptions et retards. Des sites d'exercices en ligne et une vidéo personnalisée ont été ajoutés au protocole afin d'encourager les patients à continuer de faire de l'activité physique lorsqu'ils ne pouvaient pas marcher dans des lieux publics ou étaient réticents à le faire. Limites: Cet essai a été conçu pour inclure des patients ambulatoires atteints d'IRT, il ne traite pas du fardeau de la maladie chez les patients à mobilité très restreinte.

Pharmacological strategies to manage hyperkalaemia: out with the old, in with the new? Not so fast .

Since the 1950s, sodium polystyrene sulphonate (SPS) has been the dominant cation exchange agent prescribed for hyperkalaemia. Clinicians have had plenty of time to learn of SPS's advantages and limitations. The demands of drug regulatory agencies regarding the incorporation of medications into the market were not so stringent then as they are today, and the efficacy and safety of SPS have been questioned. In recent years, two novel cation exchangers, patiromer and sodium zirconium cyclosilicate, have received (or are in the process of receiving) regulatory approval in multiple jurisdictions globally, after scrutiny of carefully conducted trials regarding their short-term and mid-term efficacy. In this debate, we defend the view that all three agents are likely to have similar efficacy. Harms are much better understood for SPS than for newer agents, but currently there are no data to suggest that novel agents are safer than SPS. Drug choices need to consider costs, access and numbers-needed-to-treat to prevent clinically important events; for potassium exchangers, we need trials directly examining clinically important events.

Absolute and Relative Risks of Kidney Outcomes Associated With Lithium vs Valproate Use in Sweden.

Importance: Among patients with bipolar disorder, discordant findings have been published on the nephrotoxic effects of lithium therapy. Objective: To quantify absolute and relative risks of chronic kidney disease (CKD) progression and acute kidney injury (AKI) in people who initiated lithium compared with valproate therapy and to investigate the association between cumulative use and elevated lithium levels and kidney outcomes. Design, Setting, and Participants: This cohort study had a new-user active-comparator design and used inverse probability of treatment weights to minimize confounding. Included patients initiated therapy with lithium or valproate from January 1, 2007, to December 31, 2018, and had a median follow-up of 4.5 years (IQR, 1.9-8.0 years). Data analysis began in September 2021, using routine health care data from the period 2006 to 2019 from the Stockholm Creatinine Measurements project, a recurrent health care use cohort of all adult residents in Stockholm, Sweden. Exposures: New use of lithium vs new use of valproate and high (>1.0 mmol/L) vs low serum lithium levels. Main Outcomes and Measures: Progression of CKD (composite of >30% decrease relative to baseline estimated glomerular filtration rate [eGFR] and kidney failure), AKI (by diagnosis or transient creatinine elevations), new albuminuria, and annual eGFR decrease. Outcomes by attained lithium levels were also compared in lithium users. Results: The study included 10 946 people (median [IQR] age, 45 [32-59] years; 6227 female [56.9%]), of whom 5308 initiated lithium therapy and 5638 valproate therapy. During follow-up, 421 CKD progression events and 770 AKI events were identified. Compared with patients who received valproate, those who received lithium did not have increased risk of CKD (hazard ratio [HR], 1.11 [95% CI, 0.86-1.45]) or AKI (HR, 0.88 [95% CI, 0.70-1.10]). Absolute 10-year CKD risks were low and similar: 8.4% in the lithium group and 8.2% in the valproate group. No difference in the risk of developing albuminuria or the annual rate of eGFR decrease was found between groups. Among more than 35 000 routine lithium tests, only 3% of results were in the toxic range (>1.0 mmol/L). Lithium values greater than 1.0 mmol/L, compared with lithium values of 1.0 mmol/L or less, were associated with increased risk of CKD progression (HR, 2.86; 95% CI, 0.97-8.45) and AKI (HR, 3.51; 95% CI, 1.41-8.76). Conclusions and Relevance: In this cohort study, compared with new use of valproate, new use of lithium was meaningfully associated with adverse kidney outcomes, with low absolute risks that did not differ between therapies. However, elevated serum lithium levels were associated with future kidney risks, particularly AKI, emphasizing the need for close monitoring and lithium dose adjustment.

Quality of laboratory biomarker monitoring during treatment with lithium in patients with bipolar disorder.

BACKGROUND: Clinical guidelines recommend monitoring of creatinine and lithium throughout treatment with lithium. We here assessed the extent to which this occurs in healthcare in Sweden. METHODS: This is an observational study of all adults with bipolar disorder starting lithium therapy in Stockholm, Sweden, during 2007-2018. The main outcome was monitoring of blood lithium and creatinine at therapy initiation and/or once annually. The secondary outcome was monitoring of calcium and thyroid-stimulating hormone (TSH). Patients were followed up until therapy cessation, death, out-migration, or to the end of 2018. RESULTS: We identified 4428 adults with bipolar disorder who started lithium therapy and were followed up for up to 11 years. Their median age was 39 years, and 63% were women. The median duration on lithium therapy was 4.3 (IQR: 1.9-7.45) years, and the majority who discontinued therapy started another mood stabilizer soon after. Overall, 21% started lithium therapy without assessing the serum/plasma concentration of creatinine. The proportion of people who did not have both lithium and creatinine measured increased from 21% in the first year to 33% in the eleventh year. The proportion with annual testing for TSH or calcium was slightly lower. As few as 16% of patients had both lithium and creatinine tested once annually during their complete time on lithium. CONCLUSIONS: In a Swedish community sample, lithium and creatinine monitoring was inconsistent with guideline recommendations that call for measurement of annual biomarker levels.

Defining measures of kidney function in observational studies using routine health care data: methodological and reporting considerations.

The availability of electronic health records and access to a large number of routine measurements of serum creatinine and urinary albumin enhance the possibilities for epidemiologic research in kidney disease. However, the frequency of health care use and laboratory testing is determined by health status and indication, imposing certain challenges when identifying patients with kidney injury or disease, when using markers of kidney function as covariates, or when evaluating kidney outcomes. Depending on the specific research question, this may influence the interpretation, generalizability, and/or validity of study results. This review illustrates the heterogeneity of working definitions of kidney disease in the scientific literature and discusses advantages and limitations of the most commonly used approaches using 3 examples. We summarize ways to identify and overcome possible biases and conclude by proposing a framework for reporting definitions of exposures and outcomes in studies of kidney disease using routinely collected health care data.

Removing race from the CKD-EPI equation and its impact on prognosis in a predominantly White European population.

BACKGROUND: While American nephrology societies recommend using the 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) estimated glomerular filtration rate (eGFR) equation without a Black race coefficient, it is unknown how this would impact disease distribution, prognosis and kidney failure risk prediction in predominantly White non-US populations. METHODS: We studied 1.6 million Stockholm adults with serum/plasma creatinine measurements between 2007 and 2019. We calculated changes in eGFR and reclassification across KDIGO GFR categories when changing from the 2009 to 2021 CKD-EPI equation; estimated associations between eGFR and the clinical outcomes kidney failure with replacement therapy (KFRT), (cardiovascular) mortality and major adverse cardiovascular events using Cox regression; and investigated prognostic accuracy (discrimination and calibration) of both equations within the Kidney Failure Risk Equation. RESULTS: Compared with the 2009 equation, the 2021 equation yielded a higher eGFR by a median [interquartile range (IQR)] of 3.9 (2.9-4.8) mL/min/1.73 m2, which was larger at older age and for men. Consequently, 9.9% of the total population and 36.2% of the population with CKD G3a-G5 was reclassified to a higher eGFR category. Reclassified individuals exhibited a lower risk of KFRT, but higher risks of all-cause/cardiovascular death and major adverse cardiovascular events, compared with non-reclassified participants of similar eGFR. eGFR by both equations strongly predicted study outcomes, with equal discrimination and calibration for the Kidney Failure Risk Equation. CONCLUSIONS: Implementing the 2021 CKD-EPI equation in predominantly White European populations would raise eGFR by a modest amount (larger at older age and in men) and shift a major proportion of CKD patients to a higher eGFR category. eGFR by both equations strongly predicted outcomes.

Cardiorenal Outcomes Among Patients With Atrial Fibrillation Treated With Oral Anticoagulants.

RATIONALE & OBJECTIVE: Direct oral anticoagulants (DOACs) have progressively replaced vitamin K antagonists (VKAs) for stroke prevention in patients with nonvalvular atrial fibrillation (AF). DOACs cause fewer bleeding complications, but their other advantages, particularly related to kidney outcomes, remain inconclusive. We studied the risks of chronic kidney disease (CKD) progression and acute kidney injury (AKI) after DOAC and VKA administration for nonvalvular AF. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Cohort study of Swedish patients enrolled in the Stockholm Creatinine Measurements (SCREAM) project with a diagnosis of nonvalvular AF during 2011-2018. EXPOSURE: Initiation of DOAC or VKA treatment. OUTCOME: Primary outcomes were CKD progression (composite of >30% estimated glomerular filtration rate [eGFR] decline and kidney failure) and AKI (by diagnosis or KDIGO-defined transient creatinine elevations). Secondary outcomes were death, major bleeding, and the composite of stroke and systemic embolism. ANALYTICAL APPROACH: Propensity score weighted Cox regression was used to balance 50 baseline confounders. Sensitivity analyses included falsification end points, subgroups, and estimation of per-protocol effects. RESULTS: We included 32,699 patients (56% initiated DOAC) who were observed for a median of 3.8 years. Their median age was 75 years, 45% were women, and 27% had an eGFR <60mL/min/1.73m2. The adjusted HRs for DOAC versus VKA were 0.87 (95% CI, 0.78-0.98) for the risk of CKD progression and 0.88 (95% CI, 0.80-0.97) for AKI. HRs were 0.77 (95% CI, 0.67-0.89) for major bleeding, 0.93 (95% CI, 0.78-1.11) for the composite of stroke and systemic embolism, and 1.04 (95% CI, 0.95-1.14) for death. The results were similar across subgroups of age, sex, and baseline eGFR when restricting to patients at high risk for thromboembolic events and when censoring follow up at treatment discontinuation or change in type of anticoagulation. LIMITATIONS: Missing information on time in therapeutic range and treatment dosages. CONCLUSIONS: Among patients with nonvalvular AF treated in routine clinical practice compared with VKA use, DOAC use was associated with a lower risk of CKD progression, AKI, and major bleeding but a similar risk of the composite of stroke, systemic embolism, or death.

Involving Patient Partners in the KRESCENT Peer Review: Intent, Process, Challenges, and Opportunities.

Purpose of review: The Kidney Research Scientist Core Education and National Training (KRESCENT) is a national Canadian training program for kidney scientists, funded by the Kidney Foundation of Canada (KFOC), the Canadian Institutes of Health Research (CIHR), and the Canadian Society of Nephrology (CSN). We describe our first year of incorporating patient partners into a scientific peer-review committee, the 2017 committee to select senior research trainees and early-career kidney researchers for funding and training, in the hope that it will be helpful to others who wish to integrate the perspective of people with lived experience into the peer-review process. Sources of information: Other peer-review committees, websites, journal articles, patient partners, Kidney Foundation of Canada Research Council, Canadians Seeking Solutions and Innovations to Overcome Chronic Kidney Disease (Can-SOLVE CKD) Patient Council, participants in the 2017 Kidney Foundation of Canada KRESCENT peer-review panel. Methods: We describe our motivation, rationale, guiding principles, plans, feedback, implementation, and response. Key findings: We disseminated a "call for patient partners" 8 weeks before the meeting, seeking patients or their care givers to partner with the KRESCENT peer-review panel; we defined these people with lived experience of kidney disease as patient partners. Eight patient partners came forward and all participated as reviewers. Patient partners first participated in a webinar to learn about the function, structure, and processes of a peer-review committee. They practiced reviewing plain language summaries and giving feedback. In a subsequent teleconference, they shared and discussed their reviews. Plain language summaries were scored, overall, on the same 0-5 quality scale used by scientific reviewers. Three patient reviewers participated in some or all of the 6-hour meeting, which was conducted as usual, for this panel, by teleconference (initially audio only; from 2020 onwards by videoconference). In the meeting, the 2 assigned scientific reviewers first gave their scores, followed by the patient reviewers giving their scores, and discussion (mostly scientific, and conducted in usual scientific language). Scientific reviewers then negotiated a consensus score based on their initial scores, the discussion, patient reviewers' scores and statements, and the scientific officer's notes. Patient reviewers, scientific reviewers, and the Kidney Foundation of Canada (KFOC) were generally positive about the process. The increased length of the meeting (estimated at 1 hour) was generally thought to be acceptable. Patient reviewers also provided feedback on the methods used to incorporate patients into the research under review. These comments were concrete, insightful, and helpful. The patients did not uniformly recommend that basic scientists involve patients in their work. We did not detect bias against preclinical science, work that did not involve patients, or rarer diseases. Some patients found participation inspiring and enlightening. All participants appreciated the idea of patient partners as community witnesses to a group process committed to fairness and supportiveness. We discussed assigning formal meaningful weight to patient reviewers' assessments. Most, but not all, patients thought that the scientific reviewers were ultimately the best judges of the allocation of scarce research resources. Limitations: Patient participants tended to be Caucasian, middle class, and well educated. Because of the difficulties of travel for some people living with or supporting those living with kidney disease, our findings may not generalize fully to peer-review meetings that are conducted face to face. This is explicitly a supportive panel, committed to reviewing junior scientists with kindness as well as rigor; our findings may not generalize to panels conducted differently. We did not use formal qualitative methodology. Implications: Inclusion of patient partners as patient reviewers for the KRESCENT program peer-review panel was feasible, added value for scientific and patient reviewers, and for the funding stakeholders (CIHR, KFOC, and CSN). We were glad that we had taken this step and continue to refine the process with each successive competition.

Motif de la revue: Le KRESCENT (Kidney Research Scientist Core Education and National Training) est un programme national de formation pour les chercheurs en santé rénale financé par la Fondation canadienne du rein (FCR), les Instituts de recherche en santé du Canada (IRSC) et la Société canadienne de néphrologie (SCN). Nous décrivons notre première année d'intégration de partenaires patients dans un comité d'examen scientifique par les pairs, le comité de 2017, visant la sélection de stagiaires de recherche et de chercheurs en santé rénale en début de carrière pour le financement et la formation, dans l'espoir que cela sera utile à ceux qui souhaitent intégrer la perspective des personnes ayant une expérience vécue au processus d'examen par les pairs. Sources: Autres comités d'examen par les pairs, sites Web, articles de revues, partenaires patients, Conseil de recherche de la Fondation canadienne du rein, conseil des patients de Canadians Seeking Solutions and Innovations to Overcome Chronic Kidney Disease (CAN-SOLVE CKD), participants au comité d'examen par les pairs de la Fondation canadienne du rein de 2017. Méthodologie: Nous décrivons ce qui a motivé cette étude, notre raisonnement, nos principes directeurs, nos plans, la rétroaction, la mise en œuvre et les réponses. Principaux résultats: Nous avons diffusé un « appel à des partenaires patients ¼ huit semaines avant la réunion pour trouver des patients ou des soignants prêts à collaborer avec le comité d'examen par les pairs de KRESCENT; nous avons défini comme partenaires patients les personnes ayant une expérience vécue de maladie rénale. Huit partenaires patients ont répondu à l'appel et tous ont participé en tant qu'examinateurs. Les partenaires patients ont d'abord participé à un webinaire pour en apprendre davantage sur la fonction, la structure et les processus d'un comité d'examen par les pairs. Ils se sont ensuite entraînés à examiner des résumés en langage simple et à donner des commentaires. Lors d'une téléconférence ultérieure, ils ont partagé et discuté de leurs examens respectifs. Les résumés en langage clair ont été notés, dans l'ensemble, sur la même échelle de qualité de 0 à 5 utilisée par les examinateurs scientifiques. Trois patients examinateurs ont participé à une partie ou à la totalité de la réunion de 6 heures, qui s'est tenue comme d'habitude, pour ce panel, par téléconférence (initialement en audio seulement; par vidéoconférence à partir de 2020). Au cours de la réunion, les deux examinateurs scientifiques désignés ont d'abord donné leurs notes, puis les patients examinateurs ont donné leurs notes, et une discussion a suivi (principalement scientifique, et menée dans le langage scientifique habituel). Les examinateurs scientifiques ont ensuite négocié pour établir une note consensuelle en fonction de leurs notes initiales, de la discussion, des notes et des commentaires des patients examinateurs et des notes de l'agent scientifique.Les patients examinateurs, les examinateurs scientifiques et la Fondation canadienne du rein étaient généralement positifs à l'égard du processus. La durée accrue de la réunion (estimée à 1 heure) a généralement été jugée acceptable. Les patients examinateurs ont également fourni des commentaires sur les méthodes utilisées pour intégrer les patients à la recherche à l'étude. Ces commentaires étaient concrets, pertinents et utiles. Les patients ne recommandent pas uniformément que les scientifiques en recherche fondamentale impliquent les patients dans leur travail. Nous n'avons pas détecté de biais contre la science préclinique, les études qui n'impliquent pas de patients ou les maladies plus rares. Certains patients ont trouvé la participation inspirante et instructive. Tous les participants ont aimé l'idée des partenaires patients comme témoins communautaires d'un processus de groupe engagé dans l'équité et le soutien.Nous avons discuté de l'attribution d'un poids formel significatif aux évaluations des patients examinateurs. La plupart des patients, mais pas tous, étaient d'avis que les examinateurs scientifiques étaient en fin de compte les meilleurs juges de l'allocation des ressources limitées de la recherche. Limites: Les patients participants étaient pour la plupart de race blanche, de classe moyenne et bien éduqués. En raison des difficultés de déplacement pour certaines personnes vivant avec ou soutenant les personnes vivant avec une maladie rénale, nos résultats peuvent ne pas se généraliser entièrement aux réunions d'examen par les pairs menées en personne. Il s'agit essentiellement d'un groupe de soutien, qui s'est engagé à examiner les jeunes chercheurs avec bienveillance et rigueur; nos conclusions peuvent ne pas se généraliser à des groupes de travail menés différemment. Nous n'avons pas utilisé de méthodologie qualitative officielle. Résultats: L'inclusion de partenaires patients comme examinateurs dans un comité d'examen par les pairs du programme KRESCENT s'est avérée réalisable, et une valeur ajoutée pour les examinateurs scientifiques, les patients examinateurs et les parties responsables du financement (IRSC, FCR et SCN). Nous sommes heureux d'avoir franchi cette étape, nous continuons de raffiner le processus à chaque concours successif.

Aldosterone, Mineralocorticoid Receptor Activation, and CKD: A Review of Evolving Treatment Paradigms.

Mineralocorticoid receptor (MR) activation is involved in propagating kidney injury, inflammation, and fibrosis and in the progression of chronic kidney disease (CKD). Multiple clinical studies have defined the efficacy of MR antagonism in attenuating progressive kidney disease, and the US Food and Drug Administration recently approved the nonsteroidal mineralocorticoid receptor antagonist (MRA) finerenone for this indication. In this review, we consider the basic science and clinical applicability of MR antagonism. Because hyperkalemia constitutes a constraint to implementing evidence-based MR blockade, we review MRA-associated hyperkalemia in the context of finerenone and discuss evolving mitigation strategies to enhance the safety and efficacy of this treatment. Although the FIDELIO-DKD and FIGARO-DKD clinical trials focused solely on patients with type 2 diabetes mellitus, we propose that MR activation and the resulting inflammation and fibrosis act as a substantive pathogenetic mediator not only in people with diabetic CKD but also in those with CKD without diabetes. We close by briefly discussing both recently initiated and future clinical trials that focus on extending the attributes of MR antagonism to a wider array of nondiabetic kidney disorders, such as patients with nonalbuminuric CKD.

Pyoderma Gangrenosum After Insertion of a Hemodialysis Catheter: Koebner Phenomenon, Systemic Inflammatory Response Syndrome, and a Delay in Diagnosis.

Rationale: Pyoderma gangrenosum is a rare neutrophilic dermatosis. Misdiagnosis of pyoderma gangrenosum as an infection is not uncommon. Pyoderma gangrenosum can be associated with Koebner phenomenon and rarely results in systemic inflammatory response syndrome and shock. Presenting concerns of the patient: A 61-year-old woman had recently started maintenance hemodialysis, using a tunneled catheter. She was admitted with fever and signs of inflammation at the catheter exit site and along the tunnel. Diagnoses: The initial diagnosis was catheter-related tunnel infection. The exit site broke down into a 5 cm × 5 cm lesion typical of pyoderma, and a new similar lesion developed at a subcutaneous injection site in her abdomen. Clinical diagnosis of pyoderma gangrenosum was made. She remained febrile despite broad antibiotic coverage and catheter removal and developed systemic inflammatory response syndrome (SIRS) that necessitated transfer to intensive care unit. Interventions: She responded well to fluids and intravenous steroids. Viral and bacterial cultures were negative throughout; echocardiography and computed tomography were unrevealing. Insertion of a new hemodialysis catheter was deferred as long as clinically possible, was undertaken while the patient was taking steroids, and was uncomplicated. Outcomes: She remained hemodynamically stable and was discharged after rehabilitation. Her wounds slowly granulated and healed. Steroids were tapered. Teaching points: To our knowledge, this is the first case report of a patient with pyoderma gangrenosum developing at the site of tunneled hemodialysis catheter. Our patient developed SIRS with no evidence of infection. We summarize 11 previous case reports of pyoderma leading to SIRS and responsive to steroids.

Justification: Le pyoderma gangrenosum est une dermatose neutrophile rare que l'on méprend souvent d'abord pour une infection. Cette affection qui peut être associée au phénomène de Koebner entraîne rarement un syndrome de réponse inflammatoire systémique (SRIS) et un choc. Présentation du cas: Une femme de 61 ans qui avait récemment amorcé un traitement d'hémodialyse d'entretien par cathéter tunnelisé. À l'admission, la patiente présentait de la fièvre et des signes d'inflammation au point d'émergence du cathéter et le long du tunnel. Diagnostic: On a d'abord diagnostiqué une infection du tunnel liée au cathéter. Le point d'émergence s'est étendu en une lésion de 5 cm x 5 cm typique du pyoderma et une nouvelle lésion similaire s'est développée sur l'abdomen à un point d'injection sous-cutanée. Un diagnostic clinique de pyoderma gangrenosum a été établi. La fièvre a persisté malgré une antibiothérapie étendue et le retrait du cathéter; la patiente a développé un SRIS qui a nécessité son transfert à l'unité des soins intensifs. Intervention: La patiente a bien répondu à l'administration de liquides et de stéroïdes par voie intraveineuse. Les cultures virales et bactériennes sont demeurées négatives tout au long; l'échocardiographie et la tomodensitométrie étaient non révélatrices. L'insertion d'un nouveau cathéter d'hémodialyse a été reportée aussi longtemps que le permettait l'état clinique de la patiente. La réinsertion a été entreprise alors que la patiente était sous stéroïdes et elle n'a pas entraîné de complications. Résultats: La patiente est restée hémodynamiquement stable et a obtenu son congé après la réinsertion. Les plaies ont granulé et guéri lentement. Les stéroïdes ont été réduits progressivement. Enseignements tirés: À notre connaissance, il s'agit du premier cas rapporté d'une patiente atteinte de pyoderma gangrenosum développé au point d'émergence d'un cathéter d'hémodialyse tunnelisé. Notre patiente a développé un SRIS sans signe d'infection. Nous résumons 11 cas précédents de pyoderma ayant entraîné un SRIS et ayant répondu aux stéroïdes.

Sex Differences in the Recognition, Monitoring, and Management of CKD in Health Care: An Observational Cohort Study.

INTRODUCTION: Reported sex differences in the etiology, population prevalence, progression rates, and health outcomes of people with CKD may be explained by differences in health care. METHODS: We evaluated sex as the variable of interest in a health care-based study of adults (n=227,847) with at least one outpatient eGFR<60 ml/min per 1.73 m2 measurement denoting probable CKD in Stockholm from 2009 to 2017. We calculated the odds ratios for diagnosis of CKD and provision of RASi and statins at inclusion, and hazard ratios for CKD diagnosis, visiting a nephrologist, or monitoring creatinine and albuminuria during follow-up. RESULTS: We identified 227,847 subjects, of whom 126,289 were women (55%). At inclusion, women had lower odds of having received a diagnostic code for CKD and were less likely to have received RASi and statins, despite having guideline-recommended indications. In time-to-event analyses, women were less likely to have received a CKD diagnosis (HR, 0.43; 95% CI, 0.42 to 0.45) and visited a nephrologist (HR, 0.46; 95% CI, 0.43 to 0.48) regardless of disease severity, presence of albuminuria, or criteria for referral. Women were also less likely to undergo monitoring of creatinine or albuminuria, including those with diabetes or hypertension. These differences remained after adjustment for comorbidities, albuminuria, and highest educational achievement, and among subjects with confirmed CKD at retesting. Although in absolute terms all nephrology-care indicators gradually improved over time, the observed sex gap persisted. CONCLUSIONS: There were profound sex differences in the detection, recognition, monitoring, referrals, and management of CKD. The disparity was also observed in people at high risk and among those who had guideline-recommended indications. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/JASN/2022_10_11_JASN2022030373.mp3.

Intensity of and Adherence to Lipid-Lowering Therapy as Predictors of Major Adverse Cardiovascular Outcomes in Patients With Coronary Heart Disease.

Background The effectiveness of lipid-lowering therapy (LLT) is affected by both intensity and adherence. This study evaluated the associations of LLT intensity, adherence, and the combination of these 2 aspects of LLT management with the risk of major adverse cardiovascular events (MACE) in people with coronary heart disease. Methods and Results This is an observational study of all adults who suffered a myocardial infarction or had coronary revascularization during 2012 to 2018 and initiated LLT in Stockholm, Sweden. Study exposures were LLT adherence (proportion of days covered), LLT intensity (expected reduction of low-density lipoprotein cholesterol), and the combined measure of adherence and intensity. At each LLT fill, adherence and intensity during the previous 12 months were calculated. The primary outcomes were MACE (nonfatal myocardial infarction or stroke and death); secondary outcomes were low-density lipoprotein cholesterol goal attainment and individual components of MACE. We studied 20 490 patients aged 68±11 years, 75% men, mean follow-up 2.6±1.1 years. Every 10% increase in 1-year adherence, intensity, or adherence-adjusted intensity was associated with a lower risk of MACE (hazard ratio [HR], 0.94 [95% CI, 0.93-0.96]; HR, 0.92 [95% CI, 0.88-0.96]; and HR, 0.91 [95% CI, 0.89-0.94], respectively) and higher odds of attaining low-density lipoprotein cholesterol goals (odds ratio [OR],1.12 [95% CI, 1.10-1.15]; OR, 1.42 [95% CI, 1.34-1.51], and OR, 1.16 [95% CI, 1.19-1.24], respectively). Among patients with good adherence (≥80%), the risk of MACE was similar with low-moderate and high-intensity LLT despite differences in the low-density lipoprotein cholesterol goal attainment with the treatment intensities. Discontinuation ≥1 year increased the risk markedly (HR,1.66 [95% CI, 1.23-2.22]). Conclusions In routine care, good adherence to LLT was associated with the greatest benefit for patients with coronary heart disease. Strategies that improve adherence and use of intensive therapies could substantially reduce cardiovascular risk.

Stopping versus continuing renin-angiotensin-system inhibitors after acute kidney injury and adverse clinical outcomes: an observational study from routine care data.

Background: The risk-benefit ratio of continuing with renin-angiotensin system inhibitors (RASi) after an episode of acute kidney injury (AKI) is unclear. While stopping RASi may prevent recurrent AKI or hyperkalaemia, it may deprive patients of the cardiovascular benefits of using RASi. Methods: We analysed outcomes of long-term RASi users experiencing AKI (stage 2 or 3, or clinically coded) during hospitalization in Stockholm and Sweden during 2007-18. We compared stopping RASi within 3 months after discharge with continuing RASi. The primary study outcome was the composite of all-cause mortality, myocardial infarction (MI) and stroke. Recurrent AKI was our secondary outcome and we considered hyperkalaemia as a positive control outcome. Propensity score overlap weighted Cox models were used to estimate hazard ratios (HRs), balancing 75 confounders. Weighted absolute risk differences (ARDs) were also determined. Results: We included 10 165 individuals, of whom 4429 stopped and 5736 continued RASi, with a median follow-up of 2.3 years. The median age was 78 years; 45% were women and median kidney function before the index episode of AKI was 55 mL/min/1.73 m2. After weighting, those who stopped had an increased risk [HR, 95% confidence interval (CI)] of the composite of death, MI and stroke [1.13, 1.07-1.19; ARD 3.7, 95% CI 2.6-4.8] compared with those who continued, a similar risk of recurrent AKI (0.94, 0.84-1.05) and a decreased risk of hyperkalaemia (0.79, 0.71-0.88). Discussion: Stopping RASi use among survivors of moderate-to-severe AKI was associated with a similar risk of recurrent AKI, but higher risk of the composite of death, MI and stroke.

Lipid-lowering treatment intensity, persistence, adherence and goal attainment in patients with coronary heart disease.

BACKGROUND: To examine patterns of lipid-lowering therapy (LLT) use, and persistence and adherence among patients with coronary heart disease and their associations with lipoprotein cholesterol (LDL-C) goal attainment. METHODS: Observational study among 26,768 patients who had suffered a myocardial infarction or had been revascularized in Stockholm during 2012 to 2018, and followed up through 2019. Outcomes included initiation of LLT, discontinuation, re-initiation, adherence to treatment and LDL-C goal attainment according to the European dyslipidaemia guidelines from 2011 and 2016 (mainly LDL-C <1.8 mmol/L). RESULTS: 82% of patients commenced or continued LLT within 90 days after discharge. Of those, 71% were dispensed an LLT prescription within 30 days (62% of them for high-intensity LLT). High-intensity LLT prescribing increased over time, from 12% in 2012 to 78% in 2018. During a median follow-up of 3 (IQR 2-5) years 73% continued to fill prescriptions for a statin, 26.3% temporarily or permanently discontinued, and 0.5% changed to non-statin LLT. Only 1.3% discontinued statin treatment permanently. Throughout observation, about 80% of patients showed good statin adherence (proportion of days covered ≥80%). LDL-C target attainment was 52% the first year and <50% during subsequent years. LDL-C goal attainment was highest among patients receiving high-intensity statin treatment and showing good treatment adherence. CONCLUSION: In secondary prevention for patients with established coronary heart disease, the proportion of LDL-C target attainment was low throughout the time period of the study, despite increasing use of high-intensity LLT and good treatment persistence and adherence.

Can Peer Review Be Kinder? Supportive Peer Review: A Re-Commitment to Kindness and a Call to Action.

Peer review aims to select articles for publication and to improve articles before publication. We believe that this process can be infused by kindness without losing rigor. In 2014, the founding editorial team of the Canadian Journal of Kidney Health and Disease (CJKHD) made an explicit commitment to treat authors as we would wish to be treated ourselves. This broader group of authors reaffirms this principle, for which we suggest the terminology "supportive review."

L'évaluation par les pairs vise à sélectionner les articles à publier et à en améliorer le contenu avant publication. Nous sommes d'avis que ce processus peut être fait avec bienveillance sans perdre en rigueur. En 2014, l'équipe de rédaction fondatrice du Canadian Journal of Kidney Health and Disease (CJKHD) a pris l'engagement ferme de traiter les auteurs comme ses membres souhaiteraient eux-mêmes être traités. Aujourd'hui, notre groupe élargi d'auteur(e)s réaffirme ce principe pour lequel nous proposons la terminologie « évaluation constructive ¼.

Fitted filtration efficiency and breathability of 2-ply cotton masks: Identification of cotton consumer categories acceptable for home-made cloth mask construction.

The objective of this study was to characterize commercially-available cotton fabrics to determine their suitability as materials for construction of cloth masks for personal and public use to reduce infectious disease spread. The study focused on cottons because of their widespread availability, moderate performance and they are recommended for inclusion in home-made masks by international health authorities. Fifty-two cottons were analyzed by electron microscopy to determine fabric characteristics and fabric weights. Sixteen fabrics were selected to test for breathability and to construct 2-ply cotton masks of a standard design to use in quantitative fit testing on a human participant. Cotton mask fitted filtration efficiencies (FFEs) for 0.02-1 µm ambient and aerosolized sodium chloride particles ranged from 40 to 66% compared with the mean medical mask FFE of 55±2%. Pressure differentials across 2-ply materials ranged from 0.57 to > 12 mm H2O/cm2 on samples of equal surface area with 6 of 16 materials exceeding the recommended medical mask limit. Models were calibrated to predict 2-ply cotton mask FFEs and differential pressures for each fabric based on pore characteristics and fabric weight. Models indicated cotton fabrics from 6 of 9 consumer categories can produce cloth masks with adequate breathability and FFEs equivalent to a medical mask: T-shirt, fashion fabric, mass-market quilting cotton, home décor fabric, bed sheets and high-quality quilting cotton. Masks from one cloth mask and the medical mask were re-tested with a mask fitter to distinguish filtration from leakage. The fabric and medical masks had 3.7% and 41.8% leakage, respectively. These results indicate a well fitted 2-ply cotton mask with overhead ties can perform similarly to a disposable 3-ply medical mask on ear loops due primarily to the superior fit of the cloth mask which compensates for its lower material filtration efficiency.