Table 1.

Staging of chronic kidney disease according to the CGA approach (Cause, Glomerular Filtration, and Albuminuria)

Cause of CKD	GFR categories (ml/min/1.73 m2)	Albuminuria categories
Presence or absence of systemic disease	G1: ≥90 (normal or high)	ACR (mg/g): A1 <30 (normal or mildly increased) A2 30–300 (moderately increased) A3 >300 (severely increased)
Location within the kidney of pathological–anatomical findings (glomerular, tubulointerstitial, vascular, cystic, and congenital diseases)	G2: 60–89 (mildly decreased)	ACR (mg/mmol): A1: <3 (normal or mildly increased) A2: 3–30 (moderately increased) A3: >300 (severely increased)
	G3a: 45–59 (mildly to moderately decreased)	AER (mg/24 h): A1: <30 (normal or mildly increased) A2: 30–300 (moderately increased) A3: >300 (severely increased)
	G3b: 30–44 (moderately to severely decreased)
	G4: 15–29 (severely decreased)
	G5: <15 [kidney failure (includes ESRD)]

CKD, chronic kidney disease; ESRD, end-stage renal disease; GFR, glomerular filtration rate; ACR, albumin-to-creatinine ratio; AER, albumin excretion rate.