Table 3.

Percentage bias and bias on a logarithmic scale (95% confidence interval) for eGFR calculated using the CKD-EPI equation and MDRD equation with mGFR by iothalamate renal clearance in different populations

eGFR range (ml/min/1.73 m2)EquationPotential Kidney DonorsPostnephrectomy Kidney DonorsNative CKDKidney RecipientsOther Organ Recipients
Percentage bias
    overallCKD-EPI−8% (−10%, −7%)−7% (−11%, −4%)6% (4%, 8%)8% (6%, 10%)9% (7%, 12%)
MDRD−18% (−19%, −16%)−15% (−18%, −12%)3% (2%, 5%)1% (0%, 3%)3% (1%, 6%)
    >90CKD-EPI−3% (−5%, −1%)−4% (−34%, 26%)16% (11%, 21%)26% (19%, 34%)18% (13%, 24%)
MDRD−8% (−11%, −5%)−17% (−49%, 14%)18% (11%, 25%)36% (22%, 51%)18% (11%, 29%))
    60 to 89CKD-EPI−13% (−15%, −11%)2% (−4%, 8%)7% (3%, 11%)14% (11%, 16%)11% (7%, 14%)
MDRD−20% (−22%, −19%)−3% (−12%, 6%)1% (−3%, 5%)6% (3%, 9%)3% (0%, 7%)
    45 to 59CKD-EPI−16% (−25%, −7%)−13% (−17%, −8%)7% (2%, 13%)3% (1%, 5%)9% (3%, 15%)
MDRD−25% (−30%, −21%)−18% (−22%, −15%)−1% (−4%, 3%)−2% (−4%, 0%)3% (−2%, 8%)
    30 to 44CKD-EPI−15% (−20%, −10%)5% (1%, 8%)4% (1%, 7%)4% (−1%, 9%)
MDRD−19% (−23%, −15%)2% (−2%, 6%)−2% (−5%, 1%)−1% (−5%, 4%)
    15 to 29CKD-EPI5% (1%, 8%)11% (3%, 19%)1% (−7%, 9%)
MDRD5% (2%, 9%)5% (−2%, 11%)3% (−7%, 13%)
    <15CKD-EPI0% (−7%, 7%)7% (−10%, 24%)7% (−29%, 43%)
MDRD2% (−5%, 9%)3% (−13%, 20%)−6% (−31%, 19%)
Bias on a logarithmic scale
    overallCKD-EPI−10% (−11%, −9%)−9% (−12%, −5%)1% (−1%, 2%)4% (3%, 6%)5% (3, 7%)
MDRD−19% (−20%,−18%)−16% (−19%, −13%)−2% (−3%, −1%)−2% (−3%, −1%)−1% (−3%, 1%)
    >90CKD-EPI−4% (−6%, −2%)−7% (−32%, 29%)11% (7%, 15%)23% (16%, 30%)15% (11%, 20%)
MDRD−9% (−12%, −6%)−18% (−45%, 22%)12% (7%, 18%)31% (19%, 44%)15% (9%, 22%)
    60 to 89CKD-EPI−14% (−16%, −13%)1% (−5%, 7%)2% (1%, 5%)11% (8%, 13%)7% (4%, 11%)
MDRD−22% (−23%, −20%)−5% (−14%, 4%)−3% (−6%, −1%)3% (1%, 6%)0% (−3%, 3%)
    45 to 59CKD-EPI−17% (−25%, −9%)−14% (−18%, −9%)1% (−2%, 4%)0% (−2%, 2%)4% (0%, 7%)
MDRD−26% (−21%, −22%)−19% (−23%, −16%)−5% (−8%, −2%)−5% (−7%, −3%)−2% (−5%, 1%)
    30 to 44CKD-EPI−15% (−20%, −10%)−1% (−3%, 2%)0% (−2%, 3%)0% (−4%, 4%)
MDRD−19% (−23%, −15%)−3% (−6%, −1%)−6% (−8%, −3%)−5% (−8%, −1%)
    15 to 29CKD-EPI−1% (−3%, 2%)5% (−2%, 12%)−4% (−11%, 4%)
MDRD−1% (−3%, 2%)−1% (−6%, 5%)−3% (−10%, 6%)
    <15CKD-EPI−7% (−11%, −3%)3% (−11%, 20%)1% (−29%, 43%)
MDRD−6% (−10%, −1%)0% (−14%, 15%)−10% (−33%, 22%)
  • The percentage bias was calculated as follows: {Σ [(eGFR − mGFR)/mGFR × 100%]}/n. The percentage bias on a logarithmic scale was calculated as follows: exp[Σ (log eGFR − log mGFR)/n] − 1. CKD-EPI, Chronic Kidney Disease Epidemiology Collaboration; MDRD, Modification of Diet in Renal Disease; eGFR, estimated GFR; mGFR, measured GFR.