Comparison and evaluation of the 2009 and 2021 chronic kidney disease-epidemiological collaboration equations among Jordanian patients with type 2 diabetes mellitus

Aims This study compared the 2009 versus 2021 chronic kidney disease (CKD) Epidemiological Collaboration (CKD-EPI) equations to calculate estimated glomerular filtration rate (eGFR) among Jordanian patients with T2DM to assess their agreement and impact on CKD staging. Methods This cross-sectional study included 2382 adult Jordanian patients with T2DM. The 2009 and 2021 CKD-EPI equations were used to calculate eGFR. Patients were reclassified according to kidney disease-Improving Global Outcomes (KDIGO) categories. Agreement between the equations was assessed using Bland–Altman plots and Lin’s concordance correlation. Results The 2021 equation significantly increased eGFR by a median of 2.1 mL/min/1.73 m 2 (interquartile range: 0.6–3.6 mL/min/1.73 m 2 ). However, there was significant agreement between equations (Kappa: 0.99; 95% confidence interval: 0.95–1.00), independent of age, sex, and the presence of hypertension. In total, 202 patients (8.5%) were reclassified to higher KDIGO categories using the 2021 equation, with category G3 being most affected. The overall prevalence of patients in the high to highest risk categories decreased (28.0% vs. 26.5%). Conclusions Although there was significant agreement with the 2009 equation, the 2021 equation increased eGFR and resulted in the reclassification of a subset of subjects according to KDIGO criteria. The uncertain impact of reducing high-risk category patients raises concerns about potential delays in referral and intervention, while holding the potential to enhance high-risk patient categorization, thus alleviating healthcare burden.