Health inequities and the inappropriate use of race in nephrology

Updates in Chronic Kidney Disease

Chronic kidney disease (CKD) affects approximately 14% of adults in the United States and is present in at least 10% of the population worldwide. Blood glucose and blood pressure control are imperative to adequately manage CKD as they are the only primary prevention measures for the condition. Recent changes in CKD evaluation and medication therapies that modify disease progression and aid in managing complications such as anemia of CKD have emerged, including a newly approved mineralocorticoid receptor antagonist and hypoxia-inducible factor-prolyl hydroxylase inhibitor, respectively. This focused update on CKD evaluation and management will review the most recent evidence and approved agents to support patients with CKD, including a review of glomerular filtration rate measurement methods such as CKD-EPI 2021 and utilization of cystatin C, Kidney Disease Improving Global Outcomes (KDIGO) guidelines, American Diabetes Association (ADA) guidelines, and primary literature supporting the use of newer agents in CKD. Checklists for managing blood pressure and blood glucose, CKD-mineral bone disorder, and anemia of CKD targeted for pharmacists are also provided. Additionally, a discussion of Centers for Medicare & Medicaid (CMS) coverage of agents approved for managing complications of CKD is included.

The IMPACT Score: Does Sex Matter?

OBJECTIVE

The Index for Mortality Prediction After Cardiac Transplantation (IMPACT) score is a quantitative risk index that predicts 1-year mortality risk, derived from United Network for Organ Sharing data in which women are underrepresented. The validity of the IMPACT score in 1-year mortality risk after OHT in women is unknown. The objective of this study was to assess differences in score performance by sex. We hypothesized that the IMPACT score is a poor predictor of 1-year mortality risk after orthotopic heart transplantation (OHT) in women.

DESIGN

In this external validation study, demographic and clinical characteristics were compared by sex. The IMPACT score was calculated and regression models were constructed for the entire sample and stratified by sex. Model discrimination was assessed with the area under the receiver operating characteristic curve, and calibration was assessed graphically.

PARTICIPANTS

Patients 18 years and older who were first-time single OHT recipients from the International Society for Heart and Lung Transplantation registry from 2009 to 2018.

MEASUREMENTS AND MAIN RESULTS

For 1-year mortality, the area under the receiver operating characteristic curve (95% confidence interval) for the full sample was 0.59 (0.57-0.60): 0.58 (0.55-0.61) for women and 0.59 (0.58-0.61) for men. The 1-year mortality was 9.4% in the overall cohort, with no difference in mortality by sex (9.0% v 9.6% women v men, p = 0.22).

CONCLUSIONS

The IMPACT score exhibited poor discrimination and calibration in the International Society for Heart and Lung Transplantation 2009-2019 cohort, overall and by sex. There was no difference in 1-year mortality between women and men.

Racial Disparities in Surgical Oncologic Research Funding and Impact on Diverse Populations

Racial disparities in surgical oncology research funding significantly impact minority researchers and diverse populations. This review explores historical factors contributing to the underrepresentation of minorities in academic medicine. Strategies for addressing these disparities include enhancing diversity in the physician workforce and improving funding opportunities for minority researchers, with the goal of improving patient outcomes and reducing cancer care disparities.

Clinical Outcomes Among High-Risk Primary Care Patients With Diabetic Kidney Disease: Methodological Challenges and Results From the STOP-DKD Study

BACKGROUND/OBJECTIVE

Slowing the progression of diabetic kidney disease (DKD) is critical. We conducted a randomized controlled trial to target risk factors for DKD progression.

METHODS

We evaluated the effect of a pharmacist-led intervention focused on supporting healthy behaviors, medication management, and self-monitoring on decline in estimated glomerular filtration rate (eGFR) for 36 months compared with an educational control.

RESULTS

We randomized 138 individuals to the intervention group and 143 to control. At baseline, mean (SD) eGFR was 80.7 (21.7) mL/min/1.73m 2 , 56% of participants had chronic kidney disease and a history of uncontrolled hypertension with a baseline SBP of 134.3 mm Hg. The mean (SD) decline in eGFR by cystatin C from baseline to 36 months was 5.0 (19.6) and 5.9 (18.6) mL/min/1.73m 2 for the control and intervention groups, respectively, with no significant between-group difference ( P =0.75).

CONCLUSIONS

We did not observe a significant difference in clinical outcomes by study arm. However, we showed that individuals with DKD will engage in a pharmacist-led intervention. The potential explanations for a lack of change in DKD risk factors can be attributed to 5 broad issues, challenges: (1) associated with enrolling patients with low eGFR and poor BP control; (2) implementing the intervention; (3) limited duration during which to observe any clinical benefit from the intervention; (4) potential co-intervention or contamination; and (5) low statistical power.

A toolbox for surfacing health equity harms and biases in large language models

Large language models (LLMs) hold promise to serve complex health information needs but also have the potential to introduce harm and exacerbate health disparities. Reliably evaluating equity-related model failures is a critical step toward developing systems that promote health equity. We present resources and methodologies for surfacing biases with potential to precipitate equity-related harms in long-form, LLM-generated answers to medical questions and conduct a large-scale empirical case study with the Med-PaLM 2 LLM. Our contributions include a multifactorial framework for human assessment of LLM-generated answers for biases and EquityMedQA, a collection of seven datasets enriched for adversarial queries. Both our human assessment framework and our dataset design process are grounded in an iterative participatory approach and review of Med-PaLM 2 answers. Through our empirical study, we find that our approach surfaces biases that may be missed by narrower evaluation approaches. Our experience underscores the importance of using diverse assessment methodologies and involving raters of varying backgrounds and expertise. While our approach is not sufficient to holistically assess whether the deployment of an artificial intelligence (AI) system promotes equitable health outcomes, we hope that it can be leveraged and built upon toward a shared goal of LLMs that promote accessible and equitable healthcare.

Should AI models be explainable to clinicians?

In the high-stakes realm of critical care, where daily decisions are crucial and clear communication is paramount, comprehending the rationale behind Artificial Intelligence (AI)-driven decisions appears essential. While AI has the potential to improve decision-making, its complexity can hinder comprehension and adherence to its recommendations. "Explainable AI" (XAI) aims to bridge this gap, enhancing confidence among patients and doctors. It also helps to meet regulatory transparency requirements, offers actionable insights, and promotes fairness and safety. Yet, defining explainability and standardising assessments are ongoing challenges and balancing performance and explainability can be needed, even if XAI is a growing field.

Incorporating Anti-racist Principles Throughout the Research Lifecycle: A Position Statement from the Society of General Internal Medicine (SGIM)

Biomedical research has advanced medicine but also contributed to widening racial and ethnic health inequities. Despite a growing acknowledgment of the need to incorporate anti-racist objectives into research, there remains a need for practical guidance for recognizing and addressing the influence of ingrained practices perpetuating racial harms, particularly for general internists. Through a review of the literature, and informed by the Research Lifecycle Framework, this position statement from the Society of General Internal Medicine presents a conceptual framework suggesting multi-level systemic changes and strategies for researchers to incorporate an anti-racist perspective throughout the research lifecycle. It begins with a clear assertion that race and ethnicity are socio-political constructs that have important consequences on health and health disparities through various forms of racism. Recommendations include leveraging a comprehensive approach to integrate anti-racist principles and acknowledging that racism, not race, drives health inequities. Individual researchers must acknowledge systemic racism's impact on health, engage in self-education to mitigate biases, hire diverse teams, and include historically excluded communities in research. Institutions must provide clear guidelines on the use of race and ethnicity in research, reject stigmatizing language, and invest in systemic commitments to diversity, equity, and anti-racism. National organizations must call for race-conscious research standards and training, and create measures to ensure accountability, establishing standards for race-conscious research for research funding. This position statement emphasizes our collective responsibility to combat systemic racism in research, and urges a transformative shift toward anti-racist practices throughout the research cycle.

Association of Preterm Birth with Adverse Glomerular Disease Outcomes in Children and Adults

Key Points

Preterm birth was a risk factor for adverse outcomes in this heterogeneous cohort of children and adults with glomerular disease. In analyses adjusted for diagnosis and apolipoprotein L1 risk status, there was less remission and faster progression of kidney disease in those born preterm. A novel finding from this study is that adults born preterm were more likely to have an apolipoprotein L1 high-risk genotype.

Background

While some studies of children with nephrotic syndrome have demonstrated worse outcomes in those born preterm compared with term, little data exist on associations of preterm birth with outcomes in adult-onset glomerular disease. Cardiovascular outcomes in those born preterm with glomerular disease are unknown.

Methods

We performed a cross-sectional and longitudinal analysis of participants in the Cure Glomerulonephropathy cohort. Preterm (<37 weeks' gestation) was compared with term (≥37 weeks' gestation). A survival analysis and adjusted Cox proportional hazards model were used to examine a composite outcome of 40% decline in eGFR or progression to kidney failure. An adjusted logistic regression model was used to examine remission of proteinuria.

Results

There were 2205 term and 235 preterm participants. Apolipoprotein L1 (APOL1 ) risk alleles were more common in those born preterm. More pediatric than adult participants in Cure Glomerulonephropathy were born preterm: 12.8% versus 7.69% (P < 0.001). Adults born preterm compared with term had a higher prevalence of FSGS (35% versus 25%, P = 0.01) and APOL1 high-risk genotype (9.4% versus 4.2%, P = 0.01). Participants born preterm had a shorter time interval to a 40% eGFR decline/kidney failure after biopsy (P = 0.001). In adjusted analysis, preterm participants were 28% more likely to develop 40% eGFR decline/kidney failure (hazard ratio: 1.28 [1.07 to 1.54], P = 0.008) and 38% less likely to attain complete remission of proteinuria (odds ratio: 0.62 [0.45 to 0.87], P = 0.006). There was no significant difference in cardiovascular events.

Conclusions

Preterm birth was a risk factor for adverse outcomes in this heterogeneous cohort of children and adults with glomerular disease. Adults born preterm were more likely to have an APOL1 high-risk genotype and FSGS. In analyses adjusted for FSGS and APOL1 risk status, there was less remission and faster progression of kidney disease in those born preterm.

Chronic kidney disease and the global public health agenda: an international consensus

Early detection is a key strategy to prevent kidney disease, its progression and related complications, but numerous studies show that awareness of kidney disease at the population level is low. Therefore, increasing knowledge and implementing sustainable solutions for early detection of kidney disease are public health priorities. Economic and epidemiological data underscore why kidney disease should be placed on the global public health agenda - kidney disease prevalence is increasing globally and it is now the seventh leading risk factor for mortality worldwide. Moreover, demographic trends, the obesity epidemic and the sequelae of climate change are all likely to increase kidney disease prevalence further, with serious implications for survival, quality of life and health care spending worldwide. Importantly, the burden of kidney disease is highest among historically disadvantaged populations that often have limited access to optimal kidney disease therapies, which greatly contributes to current socioeconomic disparities in health outcomes. This joint statement from the International Society of Nephrology, European Renal Association and American Society of Nephrology, supported by three other regional nephrology societies, advocates for the inclusion of kidney disease in the current WHO statement on major non-communicable disease drivers of premature mortality.

Diagnostic standard: assessing glomerular filtration rate

Creatinine-based estimated glomerular filtration rate (eGFR) is imprecise at individual level, due to non-GFR-related serum creatinine determinants, including atypical muscle mass. Cystatin C has the advantage of being independent of muscle mass, a feature that led to the development of race- and sex-free equations. Yet, cystatin C-based equations do not perform better than creatinine-based equations for estimating GFR unless both variables are included together. The new race-free Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation had slight opposite biases between Black and non-Black subjects in the USA, but has poorer performance than that the previous version in European populations. The European Kidney Function Consortium (EKFC) equation developed in 2021 can be used in both children and adults, is more accurate in young and old adults, and is applicable to non-white European populations, by rescaling the Q factor, i.e. population median creatinine, in a potentially universal way. A sex- and race-free cystatin C-based EKFC, with the same mathematical design, has also be defined. New developments in the field of GFR estimation would be standardization of cystatin C assays, development of creatinine-based eGFR equations that incorporate muscle mass data, implementation of new endogenous biomarkers and the use of artificial intelligence. Standardization of different GFR measurement methods would also be a future challenge, as well as new technologies for measuring GFR. Future research is also needed into discrepancies between cystatin C and creatinine, which is associated with high risk of adverse events: we need to standardize the definition of discrepancy and understand its determinants.

Enhancing Clinical Decision Support in Nephrology: Addressing Algorithmic Bias Through Artificial Intelligence Governance

There has been a steady rise in the use of clinical decision support (CDS) tools to guide nephrology as well as general clinical care. Through guidance set by federal agencies and concerns raised by clinical investigators, there has been an equal rise in understanding whether such tools exhibit algorithmic bias leading to unfairness. This has spurred the more fundamental question of whether sensitive variables such as race should be included in CDS tools. In order to properly answer this question, it is necessary to understand how algorithmic bias arises. We break down 3 sources of bias encountered when using electronic health record data to develop CDS tools: (1) use of proxy variables, (2) observability concerns and (3) underlying heterogeneity. We discuss how answering the question of whether to include sensitive variables like race often hinges more on qualitative considerations than on quantitative analysis, dependent on the function that the sensitive variable serves. Based on our experience with our own institution's CDS governance group, we show how health system-based governance committees play a central role in guiding these difficult and important considerations. Ultimately, our goal is to foster a community practice of model development and governance teams that emphasizes consciousness about sensitive variables and prioritizes equity.

Demographic trends of cardiorenal and heart failure deaths in the United States, 2011-2020

BACKGROUND

Heart failure (HF) and kidney disease frequently co-occur, increasing mortality risk. The cardiorenal syndrome results from damage to either the heart or kidney impacting the other organ. The epidemiology of cardiorenal syndrome among the general population is incompletely characterized and despite shared risk factors with HF, differences in mortality risk across key demographics have not been well described. Thus, the primary goal of this study was to analyze annual trends in cardiorenal-related mortality, evaluate if these trends differed by age, sex, and race or ethnicity, and describe these trends against a backdrop of HF mortality.

METHODS AND FINDINGS

The Centers for Disease Control and Prevention Wide-ranging ONline Data for Epidemiologic Research database was used to examine cardiorenal- and HF-related mortality in the US between 2011and 2020. International Classification of Diseases, 10 Revision codes were used to classify cardiorenal-related deaths (I13.x) and HF-related deaths (I11.0, I13.0, I13.2, and I50.x), among decedents aged 15 years or older. Decedents were further stratified by age group, sex, race, or ethnicity. Crude and age-adjusted mortality rates (AAMR) per 100,000 persons were calculated. A total of 97,135 cardiorenal-related deaths and 3,453,655 HF-related deaths occurred. Cardiorenal-related mortality (AAMR, 3.26; 95% CI: 3.23-3.28) was significantly lower than HF-related mortality (AAMR, 115.7; 95% CI: 115.6-115.8). The annual percent change (APC) was greater and increased over time for cardiorenal-related mortality (2011-2015: APC, 7.1%; 95% CI: 0.7-13.9%; 2015-2020: APC, 19.7%, 95% CI: 16.3-23.2%), whereas HF-related mortality also increased over that time period, but at a consistently lower rate (2011-2020: APC, 2.4%; 95% CI: 1.7-3.1%). Mortality was highest among older and male decedents for both causes. Cardiorenal-related deaths were more common in non-Hispanic or Latino Blacks compared to Whites, but similar rates were observed for HF-related mortality. A larger proportion of cardiorenal-related deaths, compared to HF-related deaths, listed cardiorenal syndrome as the underlying cause of death (67.0% vs. 1.2%).

CONCLUSIONS

HF-related deaths substantially outnumber cardiorenal-related deaths; however, cardiorenal-related deaths are increasing at an alarming rate with the highest burden among non-Hispanic or Latino Blacks. Continued surveillance of cardiorenal-related mortality trends is critical and future studies that contain detailed biomarker and social determinants of health information are needed to identify mechanisms underlying differences in mortality trends.

Association between secondhand smoke exposure and serum sex hormone concentrations among US female adults: a cross-sectional analysis using data from the National Health and Nutrition Examination Survey, 2013-2016

OBJECTIVE

To estimate the association between secondhand smoke (SHS) exposure and serum sex hormone concentrations in female adults (never smokers and former smokers).

DESIGN

Cross-sectional analysis.

SETTING

US National Health and Nutrition Examination Survey, 2013-2016.

OUTCOME MEASURES

Serum sex hormone measures included total testosterone (TT) and oestradiol (E2), sex hormone-binding globulin (SHBG), the ratio of TT and E2 and free androgen index (FAI). Isotope dilution-liquid chromatography tandem mass spectrometry was used to measure serum TT and E2. SHBG was measured using immunoassay. The ratio of TT and E2 and FAI were calculated. SHS exposure was defined as serum cotinine concentration of 0.05-10 ng/mL.

PARTICIPANTS

A total of 622 female participants aged ≥20 years were included in the analysis.

RESULTS

For never smokers, a doubling of serum cotinine concentration was associated with a 2.85% (95% CI 0.29% to 5.47%) increase in TT concentration and a 6.29% (95% CI 0.68% to 12.23%) increase in E2 in fully adjusted models. The never smokers in the highest quartile (Q4) of serum cotinine level exhibited a 10.30% (95% CI 0.78% to 20.72%) increase in TT concentration and a 27.75% (95% CI 5.17% to 55.17%) increase in E2 compared with those in the lowest quartile (Q1). For former smokers, SHBG was reduced by 4.36% (95% CI -8.47% to -0.07%, p for trend=0.049) when the serum cotinine level was doubled, and the SHBG of those in Q4 was reduced by 17.58% (95% CI -31.33% to -1.07%, p for trend=0.018) compared with those in Q1.

CONCLUSION

SHS was associated with serum sex hormone concentrations among female adults. In never smokers, SHS was associated with increased levels of TT and E2. In former smokers, SHS was associated with decreased SHBG levels.

Predicting solute transfer rate in patients initiating peritoneal dialysis

BACKGROUND

While assessment of membrane characteristics is fundamental to peritoneal dialysis (PD) prescription in patients initiating therapy, peritoneal equilibration test has theoretical and practical drawbacks. We wished to determine whether an equation using simple clinical variables could predict fast (above population mean) peritoneal solute transfer rate without dialysate sampling.

METHODS

We measured peritoneal solute transfer rate, as determined by peritoneal equilibration test using the 4-h dialysate to plasma creatinine ratio, in consecutive PD outpatients attending a single tertiary hospital for their first clinical follow-up within 3 months of dialysis initiation. An equation estimating peritoneal solute transfer rate based on readily available clinical variables was generated in a randomly selected modeling group and tested in a distinct validation group.

RESULTS

We included 712 patients, with 562 in the modeling group and 150 in the validation group. Mean age was 58.4 ± 15.9 with 431 (60.5%) men. Mean peritoneal solute transfer rate value was 0.73 ± 0.13. An equation based on gender, race, serum sodium and albumin yielded a receiving operator characteristics (ROC) area under the curve (AUC) to detect fast peritoneal solute transfer rate (> 0.73) of 0.74 (0.67-0.82). Estimated peritoneal solute transfer rate values based on percentiles 15th (> 0.66), 20th (> 0.68), 25th (> 0.69) and 30th (> 0.70) could rule out fast peritoneal solute transfer rate with negative predictive values of 100%, 93.5%, 84.2% and 80.0%, respectively.

CONCLUSIONS

An equation based on simple clinical variables allows ruling out fast transport in a significant proportion of patients initiating PD with a high degree of confidence without requiring dialysate sampling. This could prove useful in guiding dialysis prescription of PD patients in daily clinical practice, particularly in low-resource settings.

Development and validation of a race-agnostic computable phenotype for kidney health in adult hospitalized patients

Standard race adjustments for estimating glomerular filtration rate (GFR) and reference creatinine can yield a lower acute kidney injury (AKI) and chronic kidney disease (CKD) prevalence among African American patients than non-race adjusted estimates. We developed two race-agnostic computable phenotypes that assess kidney health among 139,152 subjects admitted to the University of Florida Health between 1/2012-8/2019 by removing the race modifier from the estimated GFR and estimated creatinine formula used by the race-adjusted algorithm (race-agnostic algorithm 1) and by utilizing 2021 CKD-EPI refit without race formula (race-agnostic algorithm 2) for calculations of the estimated GFR and estimated creatinine. We compared results using these algorithms to the race-adjusted algorithm in African American patients. Using clinical adjudication, we validated race-agnostic computable phenotypes developed for preadmission CKD and AKI presence on 300 cases. Race adjustment reclassified 2,113 (8%) to no CKD and 7,901 (29%) to a less severe CKD stage compared to race-agnostic algorithm 1 and reclassified 1,208 (5%) to no CKD and 4,606 (18%) to a less severe CKD stage compared to race-agnostic algorithm 2. Of 12,451 AKI encounters based on race-agnostic algorithm 1, race adjustment reclassified 591 to No AKI and 305 to a less severe AKI stage. Of 12,251 AKI encounters based on race-agnostic algorithm 2, race adjustment reclassified 382 to No AKI and 196 (1.6%) to a less severe AKI stage. The phenotyping algorithm based on refit without race formula performed well in identifying patients with CKD and AKI with a sensitivity of 100% (95% confidence interval [CI] 97%-100%) and 99% (95% CI 97%-100%) and a specificity of 88% (95% CI 82%-93%) and 98% (95% CI 93%-100%), respectively. Race-agnostic algorithms identified substantial proportions of additional patients with CKD and AKI compared to race-adjusted algorithm in African American patients. The phenotyping algorithm is promising in identifying patients with kidney disease and improving clinical decision-making.

Vascular damage in systemic lupus erythematosus

Vascular disease is a major cause of morbidity and mortality in patients with systemic autoimmune diseases, particularly systemic lupus erythematosus (SLE). Although comorbid cardiovascular risk factors are frequently present in patients with SLE, they do not explain the high burden of premature vascular disease. Profound innate and adaptive immune dysregulation seems to be the primary driver of accelerated vascular damage in SLE. In particular, evidence suggests that dysregulation of type 1 interferon (IFN-I) and aberrant neutrophils have key roles in the pathogenesis of vascular damage. IFN-I promotes endothelial dysfunction directly via effects on endothelial cells and indirectly via priming of immune cells that contribute to vascular damage. SLE neutrophils are vasculopathic in part because of their increased ability to form immunostimulatory neutrophil extracellular traps. Despite improvements in clinical care, cardiovascular disease remains the leading cause of mortality among patients with SLE, and treatments that improve vascular outcomes are urgently needed. Improved understanding of the mechanisms of vascular injury in inflammatory conditions such as SLE could also have implications for common cardiovascular diseases, such as atherosclerosis and hypertension, and may ultimately lead to personalized therapeutic approaches to the prevention and treatment of this potentially fatal complication.

Bias and Accuracy of Glomerular Filtration Rate Estimating Equations in the US: A Systematic Review and Meta-Analysis

Importance

There is increasing concern that continued use of a glomerular filtration rate (GFR) estimating equation adjusted for a single racial group could exacerbate chronic kidney disease-related disparities and inequalities.

Objective

To assess the performance of GFR estimating equations across varied patient populations.

Data Sources

PubMed, Embase, Web of Science, ClinicalTrials.gov, and Scopus databases were systematically searched from January 2012 to February 2023.

Study Selection

Inclusion criteria were studies that compared measured GFR with estimated GFR in adults using established reference standards and methods. A total of 6663 studies were initially identified for screening and review.

Data Extraction and Synthesis

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 2 authors independently extracted data on studies that examined the bias and accuracy of GFR estimating equations. For each outcome, a random-effects model was used to calculate pooled estimates. Data analysis was conducted from March to December 2023.

Main Outcomes and Measures

The primary outcomes were bias and accuracy of estimated GFRs in Black vs non-Black patients, as well as in individuals with chronic conditions. Bias was defined as the median difference between the measured GFR and the estimated GFR. Accuracy was assessed with P30 (the proportion of persons in a data set whose estimated GFR values were within 30% of measured GFR values) and measures of heterogeneity.

Results

A total of 12 studies with a combined 44 721 patients were included. Significant heterogeneity was found in the bias of various GFR estimation equations. Race-corrected equations and creatinine-based equations tended to overestimate GFR in Black populations and showed mixed results in non-Black populations. For creatinine-based equations, the mean bias in subgroup analysis was 2.1 mL/min/1.73 m2 (95% CI, -0.2 mL/min/1.73 m2 to 4.4 mL/min/1.73 m2) in Black persons and 1.3 mL/min/1.73 m2 (95% CI, 0.0 mL/min/1.73 m2 to 2.5 mL/min/1.73 m2) in non-Black persons. Equations using only cystatin C had small biases. Regarding accuracy, heterogeneity was high in both groups. The overall P30 was 84.5% in Black persons and 87.8% in non-Black persons. Creatinine-based equations were more accurate in non-Black persons than in Black persons. For creatinine-cystatin C equations, the P30 was higher in non-Black persons. There was no significant P30 difference in cystatin C-only equations between the 2 groups. In patients with chronic conditions, P30 values were generally less than 85%, and the biases varied widely.

Conclusions and Relevance

This systematic review and meta-analysis of GFR estimating equations suggests that there is bias in race-based GFR estimating equations, which exacerbates kidney disease disparities. Development of a GFR equation independent of race is a crucial starting point, but not the sole solution. Addressing the disproportionate burden of kidney failure on Black individuals in the US requires an enduring, multifaceted approach that should include improving diagnostics, tackling social determinants of health, confronting systemic racism, and using effective disease prevention and management strategies.

Hypertension Guidelines and Interventions

Hypertension remains one of the most prevalent conditions encountered in the primary care setting and is a major contributor to cardiovascular disease in the United States. This reality underscores the importance for primary care clinicians to have an understanding of hypertension guidelines, interventions, and population-based considerations. This article provides a succinct overview of hypertension guidelines, reviews guideline-informed approaches to hypertension screening, diagnosis, and treatment, and concludes with a thoughtful discussion of population-based considerations.

Advancing Healthcare Equity in Nephrology: Addressing Racial and Ethnic Disparities in Research Trials and Treatment Strategies

Within the healthcare sector, especially in the field of nephrology, the matter of gender and racial inequalities continues to be a critical concern that requires immediate focus. Women, particularly those of underrepresented racial groups, face significant challenges due to a lack of representation in research studies, leading to a deficit in knowledge about how kidney diseases affect them differently. These challenges are exacerbated by systemic biases in the healthcare system, which manifest in both gender and racial dimensions, hindering access to and the quality of care for kidney diseases. Addressing these complex disparities requires a recalibration of risk stratification models to include both gender- and race-specific factors and a transformation of healthcare policies to facilitate a more inclusive and sensitive approach. Essential to this transformation is the empowerment of women of all races to actively participate in their healthcare decisions and the strengthening of support systems to help them navigate the complexities of the healthcare environment. Furthermore, education programs must be designed to be culturally competent and address the unique needs and concerns of women across different racial backgrounds. Promoting a collaborative patient-provider relationship is crucial in fostering an environment where equity, dignity, and respect are at the forefront. The path to equitable nephrology care lies in a concerted, collective action from researchers, healthcare providers, policymakers, and patients, ensuring that every individual receives the highest standard of care, irrespective of gender or race.

Enhancing Quality of Life in African American Patients with Chronic Kidney Disease: An Evidence-Based Intervention

This study aimed to assess the effectiveness of achronic kidney disease (CKD) peer coach's educational intervention on the quality of life of African-American individuals with CKD. This study employed an experimental research design to assess a peer coaching educational intervention for African-American individuals with CKD. The theoretical underpinning was grounded in social learning theory, emphasizing observational learning, imitation, and modeling. 165 patients were randomly assigned to either the intervention group (n = 81) or the control group (n = 84). Pre- and post-intervention analyses showed no significant differences in most health measures between the two groups. However, the intervention group demonstrated significant improvement in the energy/fatigue subscale, witha16-point difference supporting the intervention group (p = .003). Additionally, the intervention group showed increased scores in the pain subscale (p = .015), while the control group did not. The CKD educational intervention highlighted cultural considerations and provided cost-effective strategies for social workers. It emphasizes the importance of targeted educational interventions and calls for further research and interventions to address the comprehensive needs of CKD patients and improve their quality of life.

Estimated glomerular filtration rate among intensive care unit survivors: From the removal of race coefficient to cystatin C-based equations

PURPOSE

Black race coefficient used in serum creatinine (sCr)-based estimated glomerular filtration rate (eGFR) calculation may perpetuate racial disparities. Among intensive care unit (ICU) survivors, sCr overestimates kidney function due to sarcopenia. Cystatin C (cysC) is a race- and muscle mass-independent eGFR marker. We investigated the impact of removing the race coefficient from sCr-based eGFR and compared cysC- and sCr-based eGFR in ICU survivors.

MATERIALS AND METHODS

Among 30,920 patients from 2 institutions in the Bronx and Boston, eGFR was calculated at hospital discharge using sCr-based equations with and without race coefficient (eGFRsCr2009 and eGFRsCr2021). In a subset with available cysC between ICU admission and 1-year follow-up, sCr- and cysC-based estimates were compared.

RESULTS

eGFRsCr2021 was higher than eGFRsCr2009 by a median of 4 ml/min/1.73 m2 among non-Black patients and lower by a median of 8 ml/min/1.73 m2 among Black patients. Removing race coefficient reclassified 12.9% of non-Black subjects and 16.1% of Black subjects to better and worse eGFR category, respectively, and differentially impacted the prevalence of kidney dysfunction between the institutions due to differences in racial composition. Among 51 patients with available cysC (108 measurements), cysC-based estimates were lower than sCr-based estimates (median difference 9 to 16 ml/min/1.73 m2), resulting in reclassification to worse eGFR category in 34% to 53.5% of measurements.

CONCLUSIONS

Among ICU survivors, removal of race coefficient leads to lower eGFR in Black patients and may contribute to overestimation of kidney function in non-Black patients. While cysC is rarely used, estimates based on this marker are significantly lower than those based on sCr.

Sociodemographic Disparities in Adults with Kidney Failure: A Meta-Analysis

This meta-analysis aims to assess current evidence regarding sociodemographic disparities among adults with kidney failure. Medline, Scopus, Web of Science, CENTRAL, and Google Scholar were systematically searched from inception to 20 February 2022. Overall, 165 cohort studies were included. Compared to White patients, dialysis survival was significantly better among Black (hazard ratio-HR: 0.68; 95% CI: 0.61-0.75), Asian (HR: 0.67; 95% CI: 0.61-0.72) and Hispanic patients (HR: 0.80; 95% CI: 0.73-0.88). Black individuals were associated with lower rates of successful arteriovenous fistula use, peritoneal dialysis and kidney transplantation, as well as with worse graft survival. Overall survival was significantly better in females after kidney transplantation compared to males (HR: 0.87; 95% CI: 0.84-0.90). Female sex was linked to higher rates of central venous catheter use and a lower probability of kidney transplantation. Indices of low SES were associated with higher mortality risk (HR: 1.22, 95% CI: 1.14-1.31), reduced rates of dialysis with an arteriovenous fistula, peritoneal dialysis and kidney transplantation, as well as higher graft failure risk. In conclusion, Black, Asian and Hispanic patients present better survival in dialysis, while Black, female and socially deprived patients demonstrate lower rates of successful arteriovenous fistula use and limited access to kidney transplantation. PROSPERO registration: CRD42022300839.

Glomerular Filtration Rate Estimation in Adults: Myths and Promises

BACKGROUND

In daily practice, glomerular filtration rate (GFR) is estimated with equations including renal biomarkers. Among these biomarkers, serum creatinine remains the most used. However, there are many limitations with serum creatinine, which we will discuss in the current review. We will also discuss how creatinine-based equations have been developed and what we can expect from them in terms of performance to estimate GFR.

SUMMARY

Different creatinine-based equations have been proposed. We will show the advantages of the recent European Kidney Function Consortium equation. This equation can be used in children and adults. This equation can also be used with some flexibility in different populations.

KEY MESSAGES

GFR is estimated by creatinine-based equations, but the most important for nephrologists is probably to know the limitations of these equations.

Multivariable risk model for postpartum re-presentation with hypertension: development phase

OBJECTIVES

Postpartum hypertension is one of the leading causes of re-presentation to hospital postpartum and is associated with adverse long-term cardiovascular risk. Postpartum blood pressure monitoring and management interventions have been shown to reduce hospital re-presentation, complications and long-term blood pressure control. Identifying patients at risk can be difficult as 40%-50% present with de novo postpartum hypertension. We aim to develop a risk model for postpartum re-presentation with hypertension using data readily available at the point of discharge.

DESIGN

A case-control study comparing all patients who re-presented to hospital with hypertension within 28 days post partum to a random sample of all deliveries who did not re-present with hypertension. Multivariable analysis identified risk factors and bootstrapping selected variables for inclusion in the model. The area under the receiver operator characteristic curve or C-statistic was used to test the model's discriminative ability.

SETTING

A retrospective review of all deliveries at a tertiary metropolitan hospital in Melbourne, Australia from 1 January 2016 to 30 December 2020.

RESULTS

There were 17 746 deliveries, 72 hypertension re-presentations of which 51.4% presented with de novo postpartum hypertension. 15 variables were considered for the multivariable model. We estimated a maximum of seven factors could be included to avoid overfitting. Bootstrapping selected six factors including pre-eclampsia, gestational hypertension, peak systolic blood pressure in the delivery admission, aspirin prescription and elective caesarean delivery with a C-statistic of 0.90 in a training cohort.

CONCLUSION

The development phase of this risk model builds on the three previously published models and uses factors readily available at the point of delivery admission discharge. Once tested in a validation cohort, this model could be used to identify at risk women for interventions to help prevent hypertension re-presentation and the short-term and long-term complications of postpartum hypertension.

Inequities in kidney health and kidney care

Health inequity refers to the existence of unnecessary and unfair differences in the ability of an individual or community to achieve optimal health and access appropriate care. Kidney diseases, including acute kidney injury and chronic kidney disease, are the epitome of health inequity. Kidney disease risk and outcomes are strongly associated with inequities that occur across the entire clinical course of disease. Insufficient investment across the spectrum of kidney health and kidney care is a fundamental source of inequity. In addition, social and structural inequities, including inequities in access to primary health care, education and preventative strategies, are major risk factors for, and contribute to, poorer outcomes for individuals living with kidney diseases. Access to affordable kidney care is also highly inequitable, resulting in financial hardship and catastrophic health expenditure for the most vulnerable. Solutions to these injustices require leadership and political will. The nephrology community has an important role in advocacy and in identifying and implementing solutions to dismantle inequities that affect kidney health.

Racial Disparities Following Reconstructive Flap Procedures

BACKGROUND

Prior reports have highlighted disparities in healthcare access, environmental conditions, and food insecurity between Black and White populations in the United States. However, limited studies have explored racial disparities in postoperative complications, particularly reconstructive flap surgeries.

METHODS

Cases of flap reconstruction based on named vascular pedicles were identified in the American College of Surgeons National Surgical Quality Improvement Program database and grouped into 3 time periods: 2005 to 2009, 2010 to 2014, and 2015 to 2019. Logistic regression was used to compare rates of postoperative complications between White and Black patients within each time period while controlling for comorbidities. Data for flap failure was only available from 2005 to 2010.

RESULTS

A total of 56,116 patients were included in the study, and 6293 (11.2%) were Black. Black patients were significantly younger than White patients and had increased rates of hypertension, smoking, and diabetes across all years ( P <0.01). Black patients had significantly higher rates of sepsis compared to White patients in all time periods. From 2005 to 2009, Black patients had a significantly higher incidence of flap failure (aOR=2.58, P <0.01), return to the operating room (aOR=1.53, P =0.01), and having any complication (aOR=1.48, P <0.01). From 2010 to 2019, White patients had a higher incidence of superficial surgical site infection.

CONCLUSIONS

Surgical complication rates following flap reconstruction based on a named vascular pedicle were higher for Black patients. Limited data on this topic currently exists, indicating that additional research on the drivers of racial disparities is warranted to improve plastic surgery outcomes in Black patients.

Decolonial, intersectional pedagogies in Canadian Nursing and Medical Education

Our intention is to contribute to the development of Canadian Nursing and Medical Education (NursMed) and efforts to redress deepening, intersecting health and social inequities. This paper addresses the following two research questions: (1) What are the ways in which Decolonial, Intersectional Pedagogies can inform Canadian NursMed Education with a focus on critically examining settler-colonialism, health equity, and social justice? (2) What are the potential struggles and adaptations required to integrate Decolonial, Intersectional Pedagogies within Canadian NursMed Education in service of redressing intersecting health and social inequities? Briefly, Decolonial, Intersectional Pedagogies are philosophies of learning that encourage teachers and students to reflect on health through the lenses of settler-colonialism, health equity, and social justice. Drawing on critical ethnographic research methods, we conducted in-depth interviews with 25 faculty members and engaged in participant observation of classrooms in university-based Canadian NursMed Education. The research findings are organized into three major themes, beginning with common institutional features influencing pedagogical approaches. The next set of findings addresses the complex strategies participants apply to integrate Decolonial, Intersectional Pedagogies. Lastly, the findings illustrate the emotional and spiritual toll some faculty members face when attempting to deliver Decolonial, Intersectional Pedagogies. We conclude that through the application of Decolonial, Intersectional Pedagogies teachers and students can support movements towards health equity, social justice, and unlearning/undoing settler-colonialism. This study contributes new knowledge to stimulate dialog and action regarding the role of health professions education, specifically Nursing and Medicine as an upstream determinant of health in settler-colonial nations such as Canada, United States, Australia, and New Zealand.

Implications of a Race Term in GFR Estimates Used to Predict AKI After Coronary Intervention

BACKGROUND

The prediction of mortality, bleeding, and acute kidney injury (AKI) after percutaneous coronary intervention (PCI) traditionally relied on race-based estimates of the glomerular filtration rate (GFR). Recently, race agnostic equations were developed to advance equity.

OBJECTIVES

The authors aimed to compare the accuracy and implications of various GFR equations when used to predict AKI after PCI.

METHODS

Using the National Cardiovascular Data Registry (NCDR) CathPCI data set, we identified patients undergoing PCI in 2020 and calculated their AKI risk using the 2014 NCDR AKI risk model. We created 4 AKI models per patient for each estimate of baseline renal function: the traditional GFR equation with a race term, 2 GFR equations without a race term, and serum creatinine alone. We then compared each model's performance predicting AKI.

RESULTS

Among 455,806 PCI encounters, the median age was 67 years, 32.2% were women, and 8.5% were Black. In Black patients, risk models without a race term were better calibrated than models incorporating an equation with a race term (intercept: -0.01 vs 0.15). Race-agnostic models reclassified 6% of Black patients into higher-risk categories, potentially prompting appropriate mitigation efforts. However, even with a race-agnostic model, AKI occurred in Black patients 18% more often than expected, which was not explained by captured patient or procedural characteristics.

CONCLUSIONS

Incorporating a GFR estimate without a Black race term into the NCDR AKI risk prediction model yielded more accurate prediction of AKI risk for Black patients, which has important implications for reducing disparities and benchmarking.

New and old GFR equations: a European perspective

Glomerular filtration rate (GFR) is estimated in clinical practice from equations based on the serum concentration of endogenous biomarkers and demographic data. The 2009 creatinine-based Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI2009) was recommended worldwide until 2021, when it was recalibrated to remove the African-American race factor. The CKD-EPI2009 and CKD-EPIcr2021 equations overestimate GFR of adults aged 18-30 years, with a strong overestimation in estimated GFR (eGFR) at age 18 years. CKD-EPICr2021 does not perform better than CKD-EPI2009 in US population, overestimating GFR in non-Black subjects, and underestimating it in Black subjects with the same magnitude. CKD-EPICr2021 performed worse than the CKD-EPI2009 in White Europeans, and provides no or limited performance gains in Black European and Black African populations. The European Kidney Function Consortium (EKFC) equation, which incorporates median normal value of serum creatinine in healthy population, overcomes the limitations of the CKD-EPI equations: it provides a continuity of eGFR at the transition between pediatric and adult care, and performs reasonably well in diverse populations, assuming dedicated scaling of serum creatinine (Q) values is used. The new EKFC equation based on cystatin C (EKFCCC) shares the same mathematical construction, namely, it incorporates the median cystatin C value in the general population, which is independent of sex and ethnicity. EKFCCC is therefore a sex-free and race-free equation, which performs better than the CKD-EPI equation based on cystatin C. Despite advances in the field of GFR estimation, no equation is perfectly accurate, and GFR measurement by exogenous tracer clearance is still required in specific populations and/or specific clinical situations.

Retaining Race in Chronic Kidney Disease Diagnosis and Treatment

The best overall measure of kidney function is glomerular filtration rate (GFR) as commonly estimated from serum creatinine concentrations (eGFRcr) using formulas that correct for the higher average creatinine concentrations in Blacks. After two decades of use, these formulas have come under scrutiny for estimating GFR differently in Blacks and non-Blacks. Discussions of whether to include race (Black vs. non-Black) in the calculation of eGFRcr fail to acknowledge that the original race-based eGFRcr provided the same CKD treatment recommendations for Blacks and non-Blacks based on directly (exogenously) measured GFR. Nevertheless, the National Kidney Foundation and the American Society of Nephrology Task Force on Reassessing the Inclusion of Race in Diagnosing Kidney Disease removed race in CKD treatment guidelines and pushed for the immediate adoption of a race-free eGFRcr formula by physicians and clinical laboratories. This formula is projected to negate CKD in 5.51 million White and other non-Black adults and reclassify CKD to less severe stages in another 4.59 million non-Blacks, in order to expand treatment eligibility to 434,000 Blacks not previously diagnosed and to 584,000 Blacks previously diagnosed with less severe CKD. This review examines: 1) the validity of the arguments for removing the original race correction, and 2) the performance of the proposed replacement formula. Excluding race in the derivation of eGFRcr changed the statistical bias from +3.7 to -3.6 ml/min/1.73m2 in Blacks and from +0.5 to +3.9 in non-Blacks, i.e., promoting CKD diagnosis in Blacks at the cost of restricting diagnosis in non-Blacks. By doing so, the revised eGFRcr greatly exaggerates the purported racial disparity in CKD burden. Claims that the revised formulas identify heretofore undiagnosed CKD in Blacks are not supported when studies that used kidney failure replacement therapy and mortality are interpreted as proxies for baseline CKD. Alternatively, a race-stratified eGFRcr (i.e., separate equations for Blacks and non-Blacks) would provide the least biased eGFRcr for both Blacks and non-Blacks and the best medical treatment for all patients.

Large language models encode clinical knowledge

Large language models (LLMs) have demonstrated impressive capabilities, but the bar for clinical applications is high. Attempts to assess the clinical knowledge of models typically rely on automated evaluations based on limited benchmarks. Here, to address these limitations, we present MultiMedQA, a benchmark combining six existing medical question answering datasets spanning professional medicine, research and consumer queries and a new dataset of medical questions searched online, HealthSearchQA. We propose a human evaluation framework for model answers along multiple axes including factuality, comprehension, reasoning, possible harm and bias. In addition, we evaluate Pathways Language Model1 (PaLM, a 540-billion parameter LLM) and its instruction-tuned variant, Flan-PaLM2 on MultiMedQA. Using a combination of prompting strategies, Flan-PaLM achieves state-of-the-art accuracy on every MultiMedQA multiple-choice dataset (MedQA3, MedMCQA4, PubMedQA5 and Measuring Massive Multitask Language Understanding (MMLU) clinical topics6), including 67.6% accuracy on MedQA (US Medical Licensing Exam-style questions), surpassing the prior state of the art by more than 17%. However, human evaluation reveals key gaps. To resolve this, we introduce instruction prompt tuning, a parameter-efficient approach for aligning LLMs to new domains using a few exemplars. The resulting model, Med-PaLM, performs encouragingly, but remains inferior to clinicians. We show that comprehension, knowledge recall and reasoning improve with model scale and instruction prompt tuning, suggesting the potential utility of LLMs in medicine. Our human evaluations reveal limitations of today's models, reinforcing the importance of both evaluation frameworks and method development in creating safe, helpful LLMs for clinical applications.

Clinical Algorithms with Race: An Online Database

Some clinical algorithms incorporate a person's race, ethnicity, or both as an input variable or predictor in determining diagnoses, prognoses, treatment plans, or risk assessments. Inappropriate use of race and ethnicity in clinical algorithms at the point of care may exacerbate health disparities and promote harmful practices of race-based medicine. This article describes a comprehensive search of online resources, the scientific literature, and the FDA Drug Label Information that uncovered 39 race-based risk calculators, six laboratory test results with race-based reference ranges, one race-based therapy recommendation, and 15 medications with race-based recommendations. These clinical algorithms based on race are freely accessible through an online database. This resource aims to raise awareness about the use of race-based clinical algorithms and track the progress made toward eradicating the inappropriate use of race. The database will be actively updated to include clinical algorithms based on race that were previously omitted, along with additional characteristics of these algorithms.

AACC/NKF Guidance Document on Improving Equity in Chronic Kidney Disease Care

BACKGROUND

Kidney disease (KD) is an important health equity issue with Black, Hispanic, and socioeconomically disadvantaged individuals experiencing a disproportionate disease burden. Prior to 2021, the commonly used estimated glomerular filtration rate (eGFR) equations incorporated coefficients for Black race that conferred higher GFR estimates for Black individuals compared to non-Black individuals of the same sex, age, and blood creatinine concentration. With a recognition that race does not delineate distinct biological categories, a joint task force of the National Kidney Foundation and the American Society of Nephrology recommended the adoption of the CKD-EPI 2021 race-agnostic equations.

CONTENT

This document provides guidance on implementation of the CKD-EPI 2021 equations. It describes recommendations for KD biomarker testing, and opportunities for collaboration between clinical laboratories and providers to improve KD detection in high-risk populations. Further, the document provides guidance on the use of cystatin C, and eGFR reporting and interpretation in gender-diverse populations.

SUMMARY

Implementation of the CKD-EPI 2021 eGFR equations represents progress toward health equity in the management of KD. Ongoing efforts by multidisciplinary teams, including clinical laboratorians, should focus on improved disease detection in clinically and socially high-risk populations. Routine use of cystatin C is recommended to improve the accuracy of eGFR, particularly in patients whose blood creatinine concentrations are confounded by processes other than glomerular filtration. When managing gender-diverse individuals, eGFR should be calculated and reported with both male and female coefficients. Gender-diverse individuals can benefit from a more holistic management approach, particularly at important clinical decision points.

Arteriovenous Graft Failure in the Veterans Health Administration: Outcome Disparities Associated with Race

Background Vascular access for ongoing hemodialysis often fails, frequently requiring repeated procedures to maintain vascular patency. While research has shown racial discrepancies in multiple aspects of renal failure treatment, there is poor understanding of how these factors might relate to vascular access maintenance procedures after arteriovenous graft (AVG) placement. Purpose To evaluate racial disparities associated with premature vascular access failure after percutaneous access maintenance procedures following AVG placement using a retrospective national cohort from the Veterans Health Administration (VHA). Materials and Methods All hemodialysis vascular maintenance procedures performed at VHA hospitals between October 2016 and March 2020 were identified. To ensure the sample represented patients who consistently used the VHA, patients without AVG placement within 5 years of their first maintenance procedure were excluded. Access failure was defined as a repeat access maintenance procedure or as hemodialysis catheter placement occurring 1-30 days after the index procedure. Multivariable logistic regression analyses were performed to calculate prevalence ratios (PRs) measuring the association between hemodialysis maintenance failure and African American race compared with all other races. Models controlled for vascular access history, patient socioeconomic status, and procedure and facility characteristics. Results In total, 1950 access maintenance procedures in 995 patients (mean age, 69 years ± 9 [SD], 1870 men) with an AVG created in one of 61 VHA facilities were identified. Most procedures involved African American patients (1169 of 1950, 60%) and patients residing in the South (1002 of 1950, 51%). Premature access failure occurred in 215 of 1950 (11%) procedures. When compared with all other races, African American race was associated with premature access site failure (PR, 1.4; 95% CI: 1.07, 1.43; P = .02). Among the 1057 procedures in 30 facilities with interventional radiology resident training programs, there was no evidence of racial disparity in the outcome (PR, 1.1; P = .63). Conclusion African American race was associated with higher risk-adjusted rates of premature arteriovenous graft failure after dialysis maintenance. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Forman and Davis in this issue.

Social Determinants of Health and Their Impact on the Black Race Coefficient in Serum Creatinine-Based Estimation of GFR: Secondary Analysis of MDRD and CRIC Studies

BACKGROUND

The cause for differences in serum creatinine between Black and non-Black individuals incorporated into prior GFR-estimating equations is not understood. We explored whether social determinants of health can account for this difference.

METHODS

We conducted a secondary analysis of baseline data of the Modification of Diet in Renal Disease and Chronic Renal Insufficiency Cohort studies ( N =1628 and 1423, respectively). Data in both study cohorts were stratified by race (Black versus non-Black). We first evaluated the extent to which the coefficient of Black race in estimating GFR from creatinine is explained by correlations of race with social determinants of health and non-GFR determinants of creatinine. Second, we evaluated whether the difference between race groups in adjusted mean creatinine can be explained by social determinants of health and non-GFR determinants of creatinine.

RESULTS

In models regressing measured GFR on creatinine, age, sex, and race, the coefficient for Black race was 21% (95% confidence interval, 0.176 to 0.245) in Modification of Diet in Renal Disease and 13% (95% confidence interval, 0.097 to 0.155) in the Chronic Renal Insufficiency Cohort and was not attenuated by the addition of social determinants of health, alone or in combination. In both studies, the coefficient for Black race was larger at lower versus higher income levels. In models, regressing creatinine on measured GFR, age, and sex, mean creatinine was higher in Black versus non-Black participants in both studies, with no effect of social determinants of health.

CONCLUSIONS

Adjustment for selected social determinants of health did not influence the relationship between Black race and creatinine-based estimated GFR.

Racial Disparities in Health Beliefs and Advance Care Planning Among Patients Receiving Maintenance Dialysis

CONTEXT

Among people receiving maintenance dialysis, little is known about racial disparities in the occurrence of prognostic discussions, beliefs about future health, and completion of advance care planning (ACP) documents.

OBJECTIVES

We examined whether Black patients receiving maintenance dialysis differ from White patients in prognostic discussions, beliefs about future health, and completion of ACP-related documents.

METHODS

We surveyed adult patients receiving maintenance dialysis from seven dialysis units in Cleveland, Ohio, and hospitalized patients at a tertiary care hospital in Cleveland. Of the 450 patients who were asked to participate in the study, 423 (94%) agreed. We restricted the current secondary analyses to include only Black (n=285) and White (n=114) patients. The survey assessed patients' knowledge of their kidney disease, attitudes toward chronic kidney disease (CKD) treatment, preferences for end-of-life (EoL) care, the patient-reported occurrence of prognostic discussions, experiences with kidney therapy decision making, sentiments of dialysis regret, beliefs about health over the next 12 months, and advance care planning. We used stepwise logistic regression to determine if race was associated with the occurrence of prognostic discussions, beliefs about future health, and completion of an ACP-related document, while controlling for potential confounders.

RESULTS

We found no significant difference in the frequency of prognostic discussions between Black (11.9%) versus White patients (7%) (P=0.15). However, Black patients (19%) had lower odds of believing that their health would worsen over the next 12 months (OR 0.22, CI 0.12, 0.44) and reporting completion of any ACP-related document (OR 0.5, CI 0.32, 0.81) compared to White patients CONCLUSION: Racial differences exist in beliefs about future health and completion of ACP-related documents. Systemic efforts to investigate differences in health beliefs and address racial disparities in the completion of ACP-related documents are needed.

Redressing the Harms of Race-Based Kidney Function Estimation

This Viewpoint emphasizes the urgency of abolishing race-based medical practices and explains how they have unjustly contributed to racial inequities in clinical care and health outcomes.

Rapid Progression of Focal Segmental Glomerulosclerosis in Patients with High-Risk APOL1 Genotypes

BACKGROUND

FSGS is a heterogeneous diagnosis with a guarded prognosis. Polymorphisms in the apolipoprotein L1 ( APOL1 ) gene are associated with developing FSGS and faster progression to kidney failure in affected patients. Better understanding the natural history of patients with FSGS and APOL1 risk alleles is essential to improve patient care and support the design and interpretation of interventional studies. The objective of this study was to evaluate the quantitative association between APOL1 and kidney disease progression and the interaction with other clinical and laboratory factors.

METHODS

CureGN cohort study participants with biopsy diagnosis of FSGS, regardless of self-identified race, were included. The exposure of interest was two APOL1 risk alleles (high risk) versus zero to one risk alleles (low risk). The primary outcome was eGFR slope categorized as rapid progressor (eGFR slope ≤-5 ml/min per year), intermediate progressor (slope between 0 and -5), or nonprogressor (slope ≥0). Multivariable ordinal logistic and linear regressions were used for adjusted analyses. Missing data were addressed using multiple imputation.

RESULTS

Of 650 participants, 476 (73%) had genetic testing, among whom 87 (18%) were high risk. High-risk participants were more likely to have lower median eGFR (62 [interquartile range, 36-81] versus low-risk participants 76 ml/min per 1.73 m 2 [interquartile range, 44-106]; P <0.01). In adjusted analysis, the odds of more rapid progression of eGFR was 2.75 times higher (95% confidence interval, 1.67 to 4.53; P <0.001) in the high-risk versus low-risk groups.

CONCLUSIONS

In patients with FSGS, high-risk APOL1 genotype is the predominant factor associated with more rapid loss of kidney function.

Estimated GFR With Cystatin C and Creatinine in Clinical Practice: A Retrospective Cohort Study

Rationale & Objective

Estimation of glomerular filtration rate (eGFR) and staging of chronic kidney disease (CKD) are essential to guide management. Although creatinine is routinely used, a recent national task force recommended the use of cystatin C for confirmation. The objective of this study was to examine the following parameters: (1) how cystatin C correlates with creatinine eGFR; (2) how it indicates differences in CKD staging; and (3) how it may affect kidney care delivery.

Study Design

Retrospective observational cohort study.

Setting & Participants

1,783 inpatients and outpatients who had cystatin C and creatinine levels drawn within 24 hours at Brigham Health-affiliated clinical laboratories.

Predictors

Serum creatinine levels, basic clinical/sociodemographic variables, and reasons for ordering cystatin C from a structured partial chart review.

Analytical Approach

Univariate and multivariable linear and logistic regression.

Results

Cystatin C-based eGFR was very strongly correlated with creatinine-based eGFR (Spearman correlation ρ = 0.83). Cystatin C eGFR resulted in a change to a later CKD stage in 27%, an earlier stage in 7%, and no change in 66% of patients. Black race was associated with a lower likelihood of change to a later stage (OR, 0.53; 95% CI [0.36, 0.75]; P < 0.001), whereas age (OR per year OR, 1.03; 95% CI [1.02, 1.04]; P < 0.001) and Elixhauser score (OR per point OR, 1.22; 95% CI [1.10, 1.36]; P < 0.001) were associated with a higher likelihood of change to a later stage.

Limitations

Single center, no direct measurement of clearance for comparison, and inconsistent self-identification of race/ethnicity.

Conclusions

Cystatin C eGFR correlates strongly with creatinine eGFR but can have a substantial effect on CKD staging. As cystatin C is adopted, clinicians must be informed on this impact.

Change Management Strategies Towards Dismantling Race-Based Structural Barriers in Radiology

Political momentum for antiracist policies grew out of the collective trauma highlighted during the COVID pandemic. This prompted discussions of root cause analyses for differences in health outcomes among historically underserved populations, including racial and ethnic minorities. Dismantling structural racism in medicine is an ambitious goal that requires widespread buy-in and transdisciplinary collaborations across institutions to establish systematic, rigorous approaches that enable sustainable change. Radiology is at the center of medical care and renewed focus on equity, diversity, and inclusion (EDI) provides an opportune window for radiologists to facilitate an open forum to address racialized medicine to catalyze real and lasting change. The framework of change management can help radiology practices create and maintain this change while minimizing disruption. This article discusses how change management principles can be leveraged by radiology to lead EDI interventions that will encourage honest dialogue, serve as a platform to support institutional EDI efforts, and lead to systemic change.

2009 CKD-EPI glomerular filtration rate estimation in Black individuals outside the United States: a systematic review and meta-analysis

Background

The 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation is the most used equation to estimate glomerular filtration rate (GFR), with race being a factor thereof, increasing GFR by 16% in self-identified Black persons compared with non-Black persons. However, recent publications indicate that it might overestimate GFR for Black adults outside the USA. In this meta-analysis, we assessed the accuracy, evaluated by the percentage of estimated GFR within 30% of measured GFR (P30), of the 2009 CKD-EPI equation in estimating GFR with and without the race coefficient in Black individuals outside the United States of America (USA).

Methods

We searched MEDLINE and Embase from inception to 9 July 2022, with no language restriction, supplemented by manual reference searches. Studies that assessed the CKD-EPI P30 accuracy with or without the race coefficient in Black adults outside the USA with an adequate method of GFR measurement were included. Data were extracted by independent pairs of reviewers and were pooled using a random-effects model.

Results

We included 11 studies, with a total of 1834 Black adults from South America, Africa and Europe. The race coefficient in the 2009 CKD-EPI equation significantly decreased P30 accuracy {61.9% [95% confidence interval (CI) 53-70%] versus 72.9% [95% CI 66.7-78.3%]; P = .03}.

Conclusions

Outside the USA, the 2009 CKD-EPI equation should not be used with the race coefficient, even though the 2009 CKD-EPI equation is not sufficiently accurate either way (<75%). Thus we endorse the Kidney Disease: Improving Global Outcomes guidelines to use exogenous filtration markers when this may impact clinical conduct.

National Projections for Clinical Implications of Race-Free Creatinine-Based GFR Estimating Equations

BACKGROUND

The National Kidney Foundation and American Society of Nephrology Task Force on Reassessing the Inclusion of Race in Diagnosing Kidney Disease recently recommended a new race-free creatinine-based equation for eGFR. The effect on recommended clinical care across race and ethnicity groups is unknown.

METHODS

We analyzed nationally representative cross-sectional questionnaires and medical examinations from 44,360 participants collected between 2001 and 2018 by the National Health and Nutrition Examination Survey. We quantified the number and proportion of Black, White, Hispanic, and Asian/Other adults with guideline-recommended changes in care.

RESULTS

The new equation, if applied nationally, could assign new CKD diagnoses to 434,000 (95% confidence interval [CI], 350,000 to 517,000) Black adults, reclassify 584,000 (95% CI, 508,000 to 667,000) to more advanced stages of CKD, restrict kidney donation eligibility for 246,000 (95% CI, 189,000 to 303,000), expand nephrologist referrals for 41,800 (95% CI, 19,800 to 63,800), and reduce medication dosing for 222,000 (95% CI, 169,000 to 275,000). Among non-Black adults, these changes may undo CKD diagnoses for 5.51 million (95% CI, 4.86 million to 6.16 million), reclassify 4.59 million (95% CI, 4.28 million to 4.92 million) to less advanced stages of CKD, expand kidney donation eligibility for 3.96 million (95% CI, 3.46 million to 4.46 million), reverse nephrologist referral for 75,800 (95% CI, 35,400 to 116,000), and reverse medication dose reductions for 1.47 million (95% CI, 1.22 million to 1.73 million). The racial and ethnic mix of the populations used to develop eGFR equations has a substantial effect on potential care changes.

CONCLUSION

The newly recommended 2021 CKD-EPI creatinine-based eGFR equation may result in substantial changes to recommended care for US patients of all racial and ethnic groups.

The new, race-free, Chronic Kidney Disease Epidemiology Consortium (CKD-EPI) equation to estimate glomerular filtration rate: is it applicable in Europe? A position statement by the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM)

The EFLM recommends not to implement the race-free Chronic Kidney Disease Epidemiology Consortium (CKD-EPI) equation in European laboratories and to keep the 2009 version of the CKD-EPI equation, without applying a race correction factor. This recommendation is completely in line with a recent Editorial published by the European Renal Association who has also proposed to change to a novel equation only when it has considerably better performance, trying to reach global consensus before implementing such a new glomerular filtration rate (GFR) estimation equation. In Europe, this equation could be for instance the new European Kidney Function Consortium (EKFC) equation, which is population-specific, developed from European cohorts and accurate from infants to the older old. Beyond serum creatinine, the estimating equations based on cystatin C will probably gain in popularity, especially because cystatin C seems independent of race. Finally, we must keep in mind that all GFR equations remain an estimation of GFR, especially rough at the individual level. Measuring GFR with a reference method, such as iohexol clearance, remains indicated in specific patients and/or specific situations, and here also, the role of the clinical laboratories is central and should still evolve positively in the future.

Use of Race in Kidney Function Estimation: Lessons Learned and the Path Toward Health Justice

In 2020, the nephrology community formally interrogated long-standing race-based clinical algorithms used in the field, including the kidney function estimation equations. A comprehensive understanding of the history of kidney function estimation and racial essentialism is necessary to understand underpinnings of the incorporation of a Black race coefficient into prior equations. We provide a review of this history, as well as the considerations used to develop race-free equations that are a guidepost for a more equity-oriented, scientifically rigorous future for kidney function estimation and other clinical algorithms and processes in which race may be embedded as a variable.

Performance of creatinine-based equations to estimate glomerular filtration rate in White and Black populations in Europe, Brazil and Africa

BACKGROUND

A new Chronic Kidney Disease Epidemiology Collaboration equation without the race variable has been recently proposed (CKD-EPIAS). This equation has neither been validated outside USA nor compared with the new European Kidney Function Consortium (EKFC) and Lund-Malmö Revised (LMREV) equations, developed in European cohorts.

METHODS

Standardized creatinine and measured glomerular filtration rate (GFR) from the European EKFC cohorts (n = 13 856 including 6031 individuals in the external validation cohort), from France (n = 4429, including 964 Black Europeans), from Brazil (n = 100) and from Africa (n = 508) were used to test the performances of the equations. A matched analysis between White Europeans and Black Africans or Black Europeans was performed.

RESULTS

In White Europeans (n = 9496), both the EKFC and LMREV equations outperformed CKD-EPIAS (bias of -0.6 and -3.2, respectively versus 5.0 mL/min/1.73 m², and accuracy within 30% of 86.9 and 87.4, respectively, versus 80.9%). In Black Europeans and Black Africans, the best performance was observed with the EKFC equation using a specific Q-value (= concentration of serum creatinine in healthy males and females). These results were confirmed in matched analyses, which showed that serum creatinine concentrations were different in White Europeans, Black Europeans and Black Africans for the same measured GFR, age, sex and body mass index. Creatinine differences were more relevant in males.

CONCLUSION

In a European and African cohort, the performances of CKD-EPIAS remain suboptimal. The EKFC equation, using usual or dedicated population-specific Q-values, presents the best performance in the whole age range in the European and African populations included in this study.

Removing race and body surface area indexation for estimated kidney function based drug dosing: Aminoglycosides as justification of these principles

STUDY OBJECTIVE

The use of race in medicine can contribute to health inequity. Updated equations for estimated glomerular filtration rate (eGFR) without race have been published. Likewise, de-indexation of eGFR to body surface area (BSA) has been recommended by regulatory guidance for drug dosing in renal impairment. Clinical data justifying these recommendations for drug dosing are sparse. We examined the gain or loss of precision in drug dosing with estimated creatinine clearance (eCLcr) and eGFR using serum creatinine (eGFRcr) with and without race and BSA indexation by evaluating the population pharmacokinetics of the aminoglycosides as a classic drug class to probe kidney function.

DESIGN

Medical records from adult patients treated with gentamicin or tobramycin over a 13-year period were queried. Population pharmacokinetic analyses were performed using a 1-compartment base structural model. Models compared body size descriptors as covariates of the volume of distribution (V). Estimated creatinine clearance and eGFRcr using multiple contemporary equations with and without BSA indexation were tested as covariates of clearance (CL).

MAIN RESULTS

The final data set included 2968 patients treated with either gentamicin (20.2%) or tobramycin (79.8%). Patients self-identified as Caucasian (82%), African-American (10%), or other. The median [5th, 95th percentile] weight and BSA were 80.5 [49.4, 136] kg and 1.94 [1.48, 2.56] m² , respectively. Models of eCLcr and eGFRcr without indexation to BSA had a better model fit than eGFRcr indexed to BSA for aminoglycoside CL. The 2021 Chronic Kidney Disease Epidemiology collaboration (CKD-EPI) eGFRcr equation (no race, no BSA indexation) provided a comparable model fit to the 2009 CKD-EPI eGFRcr equation (with race, no BSA indexation) for aminoglycoside CL.

CONCLUSIONS

Race is not a relevant covariate of aminoglycoside CL. The 2021 CKD-EPI eGFR equation without race and BSA indexation is a better method for gentamicin and tobramycin CL estimation. Confirmation of these results for other drugs can support the harmonization of dosing by kidney function.