Table 1.

Kidney Disease Outcomes Quality Initiative classification of chronic kidney disease^∗

Stage	Description	Estimated GFR (mL/min/1.73 m2)
1	Kidney damage + normal or elevated GFR	≥90
2	Kidney damage + mildly decreased GFR	60–89
3	Moderately decreased GFR	30–59
4	Severely decreased GFR	15–29
5	Kidney failure	<15 (or dialysis)

∗Defined as kidney damage confirmed by kidney biopsy showing pathological abnormalities or markers of damage or an estimated glomerular filtration rate (GFR) <60 mL/min/1.73 m² for ≥3 months. Adapted with permission from the National Kidney Foundation (1).