eGFRcrcl

eGFRcrcl is an estimate of the glomerular filtration rate that is derived from creatinine clearance data. The term is not as widely standardized as eGFR, and it may appear in certain laboratory reports or research contexts to indicate a GFR estimate based on creatinine clearance rather than a purely serum creatinine–based equation. When used, eGFRcrcl is typically adjusted for body size and reported as a rate per standard body surface area (1.73 m2).

Inputs and calculation can vary by setting. Creatinine clearance (CrCl) is traditionally calculated from a timed urine collection using the formula CrCl = (UCr × V) / Pcr, where UCr is urine creatinine concentration, V is urine volume, and Pcr is plasma creatinine. To express this as an estimated GFR, CrCl is often scaled to a standard body surface area: eGFRcrcl ≈ CrCl × (1.73 / BSA). Some implementations may use an estimated CrCl derived from available data rather than a full 24-hour collection. The exact equation or adjustment used can differ between laboratories or research studies.

Relationship to other measures is important. eGFRcrcl differs from eGFRcr, which uses serum creatinine with established equations (such as CKD-EPI or MDRD) and does not require a measured creatinine clearance. CrCl–based estimates can be useful when timed urine data are available or when a clearance-based approach is specifically indicated, but they are generally less precise and more susceptible to errors from urine collection issues, tubular creatinine secretion, or altered muscle mass than modern creatinine- or cystatin C–based eGFR methods.

Clinical interpretation should consider potential limitations, and in many settings, standard eGFR equations from serum creatinine are preferred for CKD staging and dosing decisions.