Table 7.

Classification of the study population according to the MDRD and CG formulasa

Subjects with Measured GFR (ml/min per 1.73 m2)NClassification Based on the MDRD FormulaClassification Based on the CG Formula
Stage 1Stage 2Stage 3Stage 4Stage 5Stage 1Stage 2Stage 3Stage 4Stage 5
≥90 (stage 1)48266.8%32.6%0.6%0%0%72.2%27.6%0.2%0%0%
60–89 (stage 2)57615.6%63.7%20.5%0.2%0%21.7%58.7%19.4%0.2%0%
30–59 (stage 3)5970.5%11.9%78.1%9.5%0%0.5%13.9%77.9%7.7%0%
15–29 (stage 4)3120%0.3%16.7%78.8%4.2%0%0.6%28.8%67.6%2.9%
<15 (stage 5)1280%0%3.1%32.0%64.8%0%0%3.1%53.9%43.0%
• a Measured GFR was used to divide the study population into five categories corresponding the five stages of CKD in the K/DOQI CKD classification (5). For each category, the subjects then were reclassified according to the MDRD formula and to the CG formula. Numbers in bold correspond to the percentages of subjects who did not change stage when their GFR level was estimated using a creatinine-based formula. The existence of kidney damage was not taken into account for this analysis.