Impact of Removing Race Variable on CKD Classification Using the Creatinine-Based 2021 CKD-EPI Equation

Diagnostic Accuracy of Creatinine-Based Equations for eGFR Estimation in Pakistanis: Evaluation of the European Kidney Function Consortium Equation vs the CKD-EPI Pakistan Equation

Introduction

Chronic Kidney Disease (CKD) is prevalent in Pakistan, necessitating accurate diagnostic methods. This study evaluates the CKD-EPI 2009, CKD-EPI 2021, CKD-EPI Pak, MDRD, and EKFC equations against creatinine clearance (CrCl) to determine their diagnostic accuracy for CKD in the Pakistani population.

Methods

n a retrospective cross-sectional study, data from 2,310 participants aged 18-70 were analyzed at The Aga Khan University in Karachi. Serum creatinine (SCr) and CrCl were recorded, and eGFR was calculated using five equations. Statistical analyses compared eGFR equations with CrCl, assessing sensitivity, specificity, and predictive values.

Results

EPI-Pak exhibited the highest sensitivity (95.15%) and agreement (94.85%) followed by EPI-2009 and EPI-2021 which showed the closest agreement with CrCl. Bland-Altman plots also indicated that EPI-Pak had the best agreement with CrCl.

Discussion

EPI-Pak outperformed other equations in estimating eGFR for the Pakistani population, aligning with previous recommendations for South Asians. EKFC, although highly specific, was less effective overall.

Conclusion

EPI-Pak is the most accurate equation for diagnosing CKD in the Pakistani population. Its clinical implementation could improve CKD diagnosis and patient outcomes. Future studies should further validate these findings with larger, diverse samples.

Striving for Equity: Examining Health Disparities in Urologic Oncology

Health disparities in urologic oncology, particularly in prostate, bladder, kidney, and testicular cancers, significantly impact patient outcomes across different demographic groups. This narrative review aims to investigate the extent and drivers of these disparities, focusing on the influence of race, socioeconomic status, and geographic location on diagnosis, treatment, and survival outcomes. We conducted a comprehensive review of the existing literature and analyzed data from national cancer databases to identify patterns of inequity. Our findings reveal that minority populations, individuals with lower socioeconomic status, and those residing in underserved areas are less likely to receive timely and guideline-based care, leading to worse outcomes. This review underscores the urgent need for targeted interventions, including policy reforms, health system restructuring, enhanced community outreach, and increased funding for disparity-focused research, to ensure equitable access to high-quality oncologic care. Addressing these disparities is crucial for improving cancer outcomes and achieving health equity in urologic oncology.

Adoption of CKD-EPI (2021) for Glomerular Filtration Rate Estimation: Implications for UK Practice

INTRODUCTION

Recommendations to move to a race-free estimating equation for glomerular filtration rate (GFR) have gained increasing prominence since 2021. We wished to determine the impact of any future adoption upon the chronic kidney disease (CKD) patient population of a large teaching hospital, with a population breakdown largely similar to that of England as a whole.

METHODS

We compared four estimating equations (Modification of Diet in Renal Disease [MDRD], CKD-EPI [2009], CKD-EPI [2021], and European Kidney Function Consortium [EKFC]) using the Bland-Altman method. Bias and precision were calculated (in both figures and percentages) for all patients with CKD and specific subgroups determined by age, ethnic group, CKD stage, and sex. CKD stage was assessed using all four equations.

RESULTS

All equations studied had a positive bias in South Asian patients and a negative bias in black patients compared to CKD-EPI (2021). Similarly, there was a positive bias in white patients across all equations studied. Comparing CKD-EPI (2009) and EKFC, this positive bias increased as patients aged; the opposite was seen with MDRD. Between 10% and 28% of patients in our dataset changed their CKD staging depending upon the estimating equation used.

DISCUSSION

Our work confirms previous findings that the MDRD equation overestimates estimated GFR (eGFR) in South Asians and underestimates eGFR in blacks. The alternative equations also demonstrated similar bias. This may, in part, explain the health inequalities seen in ethnic minority patients in the UK. Applying our findings to the UK CKD population as a whole would result in anywhere from 260,000 to 730,000 patients having their CKD stage reclassified, which in turn will impact secondary care services.

INTRODUCTION

Recommendations to move to a race-free estimating equation for glomerular filtration rate (GFR) have gained increasing prominence since 2021. We wished to determine the impact of any future adoption upon the chronic kidney disease (CKD) patient population of a large teaching hospital, with a population breakdown largely similar to that of England as a whole.

METHODS

We compared four estimating equations (Modification of Diet in Renal Disease [MDRD], CKD-EPI [2009], CKD-EPI [2021], and European Kidney Function Consortium [EKFC]) using the Bland-Altman method. Bias and precision were calculated (in both figures and percentages) for all patients with CKD and specific subgroups determined by age, ethnic group, CKD stage, and sex. CKD stage was assessed using all four equations.

RESULTS

All equations studied had a positive bias in South Asian patients and a negative bias in black patients compared to CKD-EPI (2021). Similarly, there was a positive bias in white patients across all equations studied. Comparing CKD-EPI (2009) and EKFC, this positive bias increased as patients aged; the opposite was seen with MDRD. Between 10% and 28% of patients in our dataset changed their CKD staging depending upon the estimating equation used.

DISCUSSION

Our work confirms previous findings that the MDRD equation overestimates estimated GFR (eGFR) in South Asians and underestimates eGFR in blacks. The alternative equations also demonstrated similar bias. This may, in part, explain the health inequalities seen in ethnic minority patients in the UK. Applying our findings to the UK CKD population as a whole would result in anywhere from 260,000 to 730,000 patients having their CKD stage reclassified, which in turn will impact secondary care services.

Impact of Race-Free Glomerular Filtration Rate Estimations on CKD Prevalence in the US Military Health System: A Retrospective Cohort Study

Rationale & Objective

The 2021 CKD-EPI removes Black race as a factor in calculating the estimated glomerular filtration rate (eGFR). We assessed its effect on CKD prevalence in the demographically-diverse US Military Health System.

Study Design

A retrospective calculation of the eGFR from serum creatinine measured over 2016-2019 using both the 2009 and 2021 CKD-EPI equations.

Setting & Population

Multicenter health care network with data from 1,502,607 adults in the complete case analysis and from 1,970,433 adults in an imputed race analysis.

Predictors

Serum creatinine, age, sex, and race.

Outcome

CKD stages 3-5, defined as the last eGFR persistently < 60 mL/min/1.73m2 for ≥90 days.

Analytical Approach

The t test and Kruskal-Wallis test were used for continuous variables and Χ2 for categorical data.

Results

The population in the complete case analysis had a median age of 40 years and was 18.8% Black race and 35.4% female. With the 2021 equation, the number of Black adults with CKD stages 3-5 increased by 58.1% from 4,147 to 6,556, a change in the crude prevalence from 1.47% to 2.32%. The number of non-Black adults with CKD stages 3-5 decreased by 30.4% from 27,596 to 19,213, a crude prevalence change from 2.26% to 1.58%. Similar results were seen with race imputation. Cumulatively, among adults with CKD stages 3-5 by at least one equation, 45.8% of Black adults were reclassified to more advanced stages of CKD and 44.0% of non-Black adults were reclassified to less severe stages across eGFR thresholds that could change clinical management.

Limitations

Potential underestimation of CKD in individuals with only 1 measurement.

Conclusions

Adoption of the 2021 CKD-EPI equation in the Military Health System reclassifies many Black adults into new CKD stages 3-5 or into more advanced CKD stages, with the opposite effect on non-Black adults. This may have an effect on CKD treatment and outcomes in ways that are yet unknown.

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.

A Canadian Commentary on the NKF-ASN Task Force Recommendations on Reassessing the Inclusion of Race in Diagnosing Kidney Disease

In 2021, a committee was commissioned by the Canadian Society of Nephrology to comment on the 2021 National Kidney Foundation-American Society of Nephrology Task Force recommendations on the use of race in glomerular filtration rate estimating equations. The committee met on numerous occasions and agreed on several recommendations. However, the committee did not achieve unanimity, with a minority group disagreeing with the scope of the commentary. As a result, this report presents the viewpoint of the majority members. We endorsed many of the recommendations from the National Kidney Foundation-American Society of Nephrology Task Force, most importantly that race should be removed from the estimated glomerular filtration rate creatinine-based equation. We recommend an immediate implementation of the new Chronic Kidney Disease Epidemiology Collaboration equation (2021), which does not discriminate among any group while maintaining precision. Additionally, we recommend that Canadian laboratories and provincial kidney organizations advocate for increased testing and access to cystatin C because the combination of cystatin C and creatinine in revised equations leads to more precise estimates. Finally, we recommend that future research studies evaluating the implementation of the new equations and changes to screening, diagnosis, and management across provincial health programs be prioritized in Canada.

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.

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.