[Comparison of equations to estimate the glomerular filtration in people aged 75 or older without known renal disease].
OBJECTIVE
To compare the glomerular filtration rate (GFR) of patients aged 75 and older without known renal disease estimated by the MDRD-4-IDMS (MDRD) formula, urine 24h creatinine clearance (24h-CC) and Cockroft-Gault (CG) formula.


METHODS
There were included 70 persons aged 75 and older from the geriatric external consultation. We compared the MDRD against the CG and the 24h-CC.


RESULTS
Means of GFR were: 24h-CC: 56,60 + or - 22,79 ml/min/1.73 m(2) and CG: 54,27 + or - 15,25 ml/min/1.73 m(2), significantly lower than with MDRD: 69,78 + or - 18,53 ml/min/1.73 m(2) (p<0.001). Age was correlated with the difference between CG and MDRD (coefficient of correlation: 0,59; r(2):0,34; p<0,001). Moderate agreement was obtained between MDRD with CG (k coefficient = 0.37; CI95%=0.19-0.55) and MDRD with 24-CC (k coefficient = 0.39; CI95% = 0.22-0.57).


CONCLUSIONS
The MDRD and CG formulas to estimate the FGR in people aged 75 and older are not interchangeable. There are needed specific studies in old people to establish the most precise formula.
Gómez-Pavón
Javier
J
Servicio de Geriatría, Hospital Central de la Cruz Roja, Madrid, España. javiergomezpavon@ya.com
Gálvez Barrón
César
C
Baztán Cortés
Juan José
JJ
Ruipérez Cantera
Isidoro
I
D000368:Aged; D000369:Aged, 80 and over; D003401:Creatine / Q000652:urine; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008433:Mathematics
D003401:Creatine