Comparison of Low eGFR Prevalence and Prediction for Mortality Using 2009 and 2021 CKD Epidemiology Collaboration Equations in Mexican Adults

Accurate eGFR is essential for identifying and managing CKD. The CKD Epidemiology Collaboration (CKD-EPI) 2021 equation removed the race coefficient from the 2009 version, but its effect in Mexican populations remains unclear. Here, we compared eGFR category prevalence, and predictive performance between the CKD-EPI 2009 and 2021 creatinine-based eGFR equations, as well as the prognostic relevance of reclassification in eGFR categories using the 2021 equation in Mexicans. We evaluated 25,110 adults who were at least aged 20 years from the 2016-2023 cycles of the Mexican National Health and Nutrition Survey to estimate national low eGFR and eGFR category prevalence using both equations. We also assessed 5-year and 10-year risk of all-cause, cardiovascular, and kidney-related mortality in 142,884 adults from the Mexico City Prospective Study using Cox proportional hazards and Fine and Gray regression models. In Mexican National Health and Nutrition Survey 2023, prevalence of eGFR <60 ml/min per 1.73 m 2 was lower with CKD-EPI 2021 (3%; 95% confidence interval [CI], 2% to 4%) compared with the 2009 equation (4%; 95% CI, 2% to 5%). Use of the 2021 equation resulted in upward eGFR reclassification in 7% (95% CI, 4% to 9%) of adults 20 years or older, particularly among older adults and those with hypertension or diabetes, yielding a reduction in 486,532 adults identified with eGFR <60 ml/min per 1.73 m 2 compared with the 2009 equation. In Mexico City Prospective Study, despite both equations showing similar C-statistics, the 2021 equation reclassified 8.3% of participants to higher eGFR categories, and reclassification was associated with lower risk of 5-year and 10-year all-cause, cardiovascular, and kidney-related mortality, particularly for participants reclassified upward from G3a to G5 categories. The CKD-EPI 2021 equation yields lower prevalence of low eGFR but leads to prognostically relevant eGFR category reclassification compared with the 2009 equation. Our findings support the implementation of the 2021 equation for population health monitoring in Mexico without compromising prognostic utility.