Rethinking Kidney Function Tests: Fresh Research Highlights Ethnic Disparities
New findings presented at UK Kidney Week 2026 are prompting a critical re-evaluation of how kidney function is assessed, particularly for individuals from diverse ethnic backgrounds. The AIM CKD UK study reveals that commonly used equations to estimate glomerular filtration rate (eGFR) – a key measure of kidney health – can significantly misclassify kidney function, potentially leading to delayed diagnosis and treatment of chronic kidney disease (CKD).
The Problem with Current eGFR Equations
Accurate assessment of kidney function is vital for diagnosing and managing CKD. However, the study, involving nearly 16,000 adults across 11 UK centres, demonstrates that creatinine-based eGFR equations systematically overestimate kidney function. What we have is particularly concerning as it can lead to a false sense of security and delay crucial interventions.
Researchers compared five widely used equations – MDRD, CKD-EPI-2009, CKD-EPI-2021, EKFC, and Lund-Malmö Revised (LMR) – against measured GFR (mGFR). The LMR equation consistently showed the best performance, with the lowest bias and highest accuracy (86% P30 accuracy). The EKFC equation too performed well (83.6% P30 accuracy). In contrast, the CKD-EPI-2009, MDRD, and CKD-EPI-2021 equations showed significantly lower accuracy.
Ethnic Disparities in eGFR Accuracy
The study uncovered significant variations in equation performance across different ethnic groups. While LMR and EKFC performed well in White participants (87% and 85% P30 accuracy, respectively), accuracy dropped considerably in Black and South Asian individuals. Specifically, the CKD-EPI-2021 equation overestimated kidney function in South Asian participants by almost 18 mL/min/1.73m² and achieved only 58% accuracy.
This disparity is crucial because inaccurate eGFR results can have real-world consequences. The study found that equation choice directly impacted clinical classification and treatment eligibility, potentially delaying access to therapies like Dapagliflozin for up to half of patients depending on the equation used.
Beyond Ethnicity: Other Factors Affecting Accuracy
The research also highlighted that eGFR accuracy isn’t solely linked to ethnicity. Reduced performance was observed in younger adults (under 25) and individuals with low body mass index or hypoalbuminaemia. This underscores the limitations of creatinine as a biomarker in certain populations.
Implications for Clinical Practice and Future Trends
The findings strongly suggest that continued reliance on CKD-EPI equations may underestimate CKD severity and exacerbate existing health inequities. Adopting the LMR or EKFC equations in clinical practice could significantly improve diagnostic accuracy and ensure more equitable access to treatment across diverse populations.
The National Institute for Health and Care Excellence (NICE) has already prioritised kidney disease for guidance updates in 2026, signaling a growing recognition of the need for improved diagnostic and treatment strategies. This prioritization, coupled with the AIM CKD UK study’s findings, could drive a shift towards more accurate and equitable kidney care in the UK.
the World Health Organisation’s recent political declaration on non-communicable diseases, which includes CKD, may encourage governments to prioritize national kidney strategies and allocate funding for research and improved care.
FAQ
Q: What is eGFR?
A: eGFR stands for estimated glomerular filtration rate. It’s a measure of how well your kidneys are filtering waste from your blood.
Q: Why are some eGFR equations more accurate than others?
A: Different equations employ different formulas to estimate kidney function. Some equations are better calibrated for specific populations and characteristics.
Q: How does ethnicity affect eGFR accuracy?
A: Creatinine levels can vary based on muscle mass and other factors that are influenced by ethnicity, leading to inaccuracies when using standard eGFR equations.
Q: What should patients do if they are concerned about their eGFR results?
A: Discuss your results with your doctor and ask if a more accurate method of assessing kidney function, such as measured GFR, is appropriate.
Pro Tip: If you are from an ethnic minority group, be sure to discuss potential inaccuracies in eGFR testing with your healthcare provider.
Seek to learn more about kidney health? Visit Kidney Care UK for resources and support.
