Implementing Kidney Disease: Improving Global Outcomes 2024 Through Laboratory-Estimated GFR Across Ages

Chronic kidney disease (CKD) represents a major public health issue, with early detection depending on accurate estimation of glomerular filtration rate (GFR). The 2024 Kidney Disease: Improving Global Outcomes (KDIGO) guidelines recommend age-adapted equations, whereas the 2009 CKD Epidemiology Collaboration (CKD-EPI) equation remains widely used in Europe despite its inapplicability in children and uncertain performance in young adults and the elderly. The objectives of this study were to compare the European Kidney Function Consortium (EKFC) and 2009 CKD-EPI equations for estimated GFR (eGFR)-based CKD staging in a general population (PCrAGE substudy), and to evaluate their performance against measured GFR (mGFR) in a reference cohort (mGFR substudy).

We analyzed data from 30,104 individuals aged 2 to 99 years with plasma creatinine (PCr) available (PCrAGE). eGFR was calculated using EKFC (all ages), CKD-EPI (adults), and Berlin Initiative Study 1 (BIS1, aged > 70 years). Performance was tested in 4144 mGFR measurements using bias and P30 across age groups and CKD stages.

In PCrAGE, switching from CKD-EPI to EKFC impacted CKD staging (3.2% from stage II to III; 0.4% from stage III tp IV). In the mGFR cohort, all equations showed declining accuracy with advancing CKD stage. EKFC consistently had the lowest bias and highest P30 in adults. CKD-EPI performed poorly in young adults (aged 18-25 years), showing substantial positive bias (∼20 ml/min per 1.73 m²) and reduced accuracy. In older adults (aged > 70 years), performance was similar across equations.

EKFC provides a continuous and robust equation for eGFR estimation across the lifespan, offering an advantage over CKD-EPI.