Predictive performance of renal function estimate equations in renal allografts

Abstract

Aims Various mathematical models have been developed to estimate glomerular filtration rate (GFR) incorporating variables such as age, gender, height, weight, serum creatinine, and body surface area (BSA). Because adjustments in drug dosing are often based on estimated values of renal function, it is important to define which, if any, of the available models, is appropriate for a specific patient population. A study was undertaken to determine the bias and precision of four mathematical models to estimate GFR in renal allograft recipients. Methods A retrospective review of 142 stable renal allograft patients, using iohexol clearance as a determinant of GFR, was performed. Renal allograft recipients followed in an outpatient clinic setting underwent iohexol clearance studies as part of clinical monitoring in the post-transplant period. Measured GFR values were compared with four mathematical models used to estimate GFR: the CockcroftGault equation, the Jelliffe equation, the Walser equation, and the Mawer equation. Bias and precision were determined for each model as the mean squared error and the mean squared error, respectively. Results Patients had a mean age of 44±13 years, 92 were male, and 50 were female. The serum creatinine concentration was 176.8±88.4 mmol l −1 (mean±s.d.).The mean time post-transplant was 5.1±5.0 years and 38% of patients had insulinrequiring diabetes mellitus. The bias and precision results for the Jelliffe, Walser, Cockcroft-Gault, and Mawer models were: −3 and 414; −5 and 381; 16 and 688; and 23 and 1084, respectively. Conclusions The Jelliffe and Walser equations gave the least biased and most precise estimations of GFR when compared with iohexol-derived measures in patients with renal allografts.

Performance of Different Prediction Equations for Estimating Renal Function in Kidney Transplantation

“…Most of these formulas have been just developed and tested to routinely assess renal function in patients with chronic renal failure, but their performance and suitability to monitor graft function in the kidney transplant settings have been tested so far in very few instances (10)(11)(12). Most of them, however, have been performed with a small number of patients, and none has explored their value in assessing the progressive decline in GFR post-transplant.…”

Predictive Performance of Renal Function Equations for Patients with Chronic Kidney Disease and Normal Serum Creatinine Levels

“…Although previous studies focused on validating these prediction equations among patients with elevated serum creatinine levels and in other subpopulations (9,(13)(14)(15), these equations have not been tested in a CKD population with normal-range serum creatinine levels. This study aimed to address this issue by comparing the results of renal function prediction equations with iohexol GFR measurements (16) for a population of subjects with documented CKD and serum creatinine levels of Յ1.5 mg/dl.…”

Significance of Anticardiolipin Antibodies on Short and Long Term Allograft Survival and Function following Kidney Transplantation

“…There were no graft losses, although four of the six did not receive anticoagulation. Among 46 recipients who had lower positive titers of ACA (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30), only six received anticoagulation, yet there were no graft losses secondary to vascular thrombosis. Therefore, of the 61 ACA positive recipients, graft loss due to thrombosis occurred only among those with very high titer (i.e.…”