Serum creatinine and estimated glomerular filtration rate (eGFR), determined using the Modification of Diet Renal Disease (MDRD)-4, the MDRD-6 or the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, substantially overestimate kidney function in patients with liver cirrhosis [1]. By directly measuring GFR, Kalafateli et al. developed an alternative eGFR formula, the Royal Free Hospital (RFH) cirrhosis GFR, that more accurately estimates GFR in cirrhotic patients [2]. The tight correlation between measured GFR and RFH cirrhosis GFR was later confirmed by Pedersen et al.
