Comparison of estimated creatinine clearance among five formulae (Cockroft-Gault, Jelliffe, Sanaka, simplified 4-variable MDRD and DAF) and the 24hours-urine-collection creatinine clearance.

BACKGROUND

GFR estimation is of major importance in everyday clinical practice. Usually it is done using one of the many eGFR equations available. In this study we compared in our population four widespread eGFR equations and our own empirical eGFR, with creatinine clearance calculated through a timed urine collection.

PATIENTS AND METHODS

We collected laboratory data of 907 patients from our clinic and outpatient department through a ten-year period and statistically compared the eGFR results between them and with the timed urine collection creatinine clearances.

RESULTS

All eGFR equations gave acceptable approximations to the timed urine collection creatinine clearances. However, in different subpopulations some equations did better than others, without any clear advantage of any equation overall. Surprisingly, our empirical equation named DAF also gave acceptable approximations regardless of age, weight and sex of the patient.

CONCLUSIONS

In our population our empirical eGFR method (DAF) gave satisfactory results regarding the monitoring of renal function, compared with four other eGFR methods. We suggest that it could provide a very fast and easy to use means of eGFR calculation.