Evaluation of Creatinine Clearance Estimation in an Elderly Male Population

Abstract

Thirty-one medically stable, elderly males (age 75 +/- 8.3 yrs) participated in a prospective study evaluating the accuracy of 16 methods of estimating creatinine clearance. Serum creatinine values were determined on the mornings of days 1, 4, and 5 to assure stable renal function. On the morning of day 3, a 24-hour urine collection was initiated. A statistically significant correlation existed between the measured and estimated clearance values for all 16 formulas. The correlation (r less than 0.65) was lower than that in previously published studies, however. Five of the formulas (1A, 5A, 5B, 7A, 7B) demonstrated no statistical difference between mean measured and estimated values. In this population, formula 2B was the least biased and formula 9B the most accurate. For all 16 methods, the bias was minimal and the relative accuracy of the estimated methods was comparable. The results support using methods to estimate creatinine clearance only as a rough bedside prediction of renal function in elderly males.

Predictive Performance of Ten Equations for Estimating Creatinine Clearance in Cardiac Patients

“…For example, in elderly patients, the Cockcroft-Gault equation has been deemed biased in overestimating Cl cr compared with the Jelliffe 1973, Hull, and Mawer equations. 7 Conversely, the Cockcroft-Gault equation has been shown to underestimate Cl cr , and to be more biased than the Jelliffe 1973, 34 Mawer, Gates, and Hull equations. 35 It has also been shown 36 that a formula that adjusts for serum albumin concentration in elderly patients with muscle atrophy may increase the accuracy and decrease the bias of estimating Cl cr compared with the Cockcroft-Gault equation.…”

Measured versus Estimated Creatinine Clearance in a High‐Functioning Elderly Sample: MacArthur Foundation Study of Successful Aging

“…Frequency of incorrect placement of individuals into renal function categories (ie, normal = 50 + mL/min, impaired = 10–50 mL/min), as put forth by Laurence and Bennett, 33 was calculated using heterogenous chi square analysis. Chi square analysis was performed on the uppermost 10%, lowermost 10%, and middle 10%–90% residuals to assess the influence of obesity, emaciation, diabetes, hypertension, albuminemia, or creatinine‐ or glomerular filtration‐altering drugs (amphotericin B, androgens, ascorbic acid, barbiturates, cephalosporin antibiotics, cimetidine, clofibrate, corticosteroids, cotrimoxazole, diuretics, levodopa, methicillin, methyldopa, nephrotoxins, nitrofurantoin, streptokinase, sulfamethoxazole and trimethaprim) 16 on outlier status, with outlier status determined by residual analysis of equations 4 and 15.…”

“…Unfortunately, many equations were developed and/or validated on very selective samples, causing difficulty in the extrapolation of results. The samples often consisted of few subjects, 5,12–16 a single gender or race, 1,3,4,8,13,16,17 and/or debilitated or institutionalized individuals 12,13 . In other studies, the chronically ill or those taking creatinine‐altering medications were excluded prior to analysis 15,18 .…”

Impact of renal function on treatment options and outcomes in advanced non-small cell lung cancer

“…9,29 Indeed, the reliability of these methods has been question ed. 9,30 However, other approaches are unlikely to provide better determinations. Measured CrCl depends on accurate 12- or 24-hour urine collections, which are difficult to achieve in ambulatory and even hospital settings.…”