| Abstract
| - Background: the Modification of Diet in Renal Disease (MDRD) method of renal function estimation has not been extensively assessed in elderly patients. We needed to assess which renal function estimate was most suited for drug dose estimation in our population. Method: we compared MDRD with an optimised version of the Cockcroft-Gault (CGopt) method in a hospital population, using gentamicin clearance as a baseline. Results: MDRD overestimated gentamicin clearance by 29% (P < 0.001, n = 68), while CGopt underestimated by 10% (P < 0.01). Overestimation by MDRD increased with increasing age. This was 12%, 26% and 69% in age groups <65, 65-80 and >80 years respectively (P < 0.001). CGopt underestimated renal function by −5%, −16% and −4% respectively (P = NS). Bias and precision of renal function estimations for the three age groups were less for CGopt than for MDRD. Age significantly influenced MDRD overestimation in this population (P = 0.037). Conclusion: MDRD overestimated renal function as age increased. While CGopt underestimated renal function, this was of a smaller magnitude, consistent across age, and thus better suited for dose calculation, especially in the elderly. Larger-scale studies using gold standard markers of renal function estimation are urgently needed to determine the accuracy of MDRD in elderly hospitalised patients.
|
