Table 3.

Association of measured GFR with estimated GFR by the MDRD formulaa

Measured GFR Range (ml/min per 1.73 m2)Estimate GFR Range (ml/min per 1.73 m2)
<3030–6060–90>90
<3063.6%2.2%0.1%0%
30–603.5%11.7%4.6%0.1%
60–900%1.4%6.9%1.3%
>900%0.2%0.7%3.5%
  • a Shown are the percentages of the 828 CKD patients with measured GFR in the indicated ranges. Patients with GFR that fell precisely at a boundary point (30, 60, or 90 ml/min per 1.73 m2) were classified in the category with lower GFR. Estimated sensi-tivity and specificity of eGFRMDRD for identifying patients with iGFR <60 ml/min per 1.73 m2 are 94.4 and 72.0%, respectively. These estimates should be interpreted with great caution because they treat iGFR as the ′true GFR,′ thus presuming the absence of measurement error.