Comparison of the 2021 and 2009 chronic kidney disease epidemiology collaboration creatinine equation for estimated glomerular filtration rate in a Chinese population

Objectives: To retrospectively compare the clinical effects of the newly released 2021 and 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations for estimated glomerular filtration rate based on creatinine (eGFRcr) in a Chinese population with a broad spectrum of clinical characteristics using historical data.Design and methods: Patients and healthy individuals who visited the Zhongshan Hospital, Fudan University, between July 1, 2020, and July 1, 2022, were enrolled. The exclusion criteria were age < 18 years, amputees, pregnant women, patients with muscle-related diseases, and patients who had undergone ultrafiltration or dialysis. The final study population included 1,051,827 patients with a median age of 57 years; 57.24% of the enrolled individuals were men. eGFRcr was calculated using the 2009 and 2021 CKD-EPI equations and initial creatinine level. Results were evaluated statistically by sex, age, creatinine level, and CKD stage.Results: The 2021 equation increased the eGFRcr in all participants compared to the 2009 equation by 4.46%. The median eGFRcr deviation of the 2021 CKD-EPI equation compared to the 2009 CKD-EPI equation was 4 ml/ min/1.73 m2. 903,443 subjects (85.89%) had higher eGFRcr owing to the utilization of the 2021 CKD-EPI equation, which did not cause CKD stage change. A total of 11.57% of subjects (121,666) had improved CKD stage with the 2021 CKD-EPI equation. 1.79% (18,817) had the same CKD stage with both equations, and 0.75% (7,901) had lower eGFRcr but no change in the CKD stage with the 2021 equation.Conclusions: The 2021 CKD-EPI equation typically produces higher eGFRcr results than the 2009 version. Applying the new equation could lead to changes in the CKD stage for some patients, which doctors should consider.