Why Classify CKD?

To have a more precise picture of each patient’s condition
To guide decisions for testing and treatment
Because neither the category of GFR nor the category of albuminuria alone can fully capture prognosis of CKD
To evaluate patient’s risk of progression and complications
- Recognize that small fluctuations in GFR are common and are not necessarily indicative of progression
- Understand that prognosis will vary depending on:
  - Cause
  - GFR
  - Degree of albuminuria; and
  - Other comorbid conditions

Examples of CGA Staging
Cause	GFR category	Albuminuria category	Criterion for CKD
Diabetic kidney disease	G5	A3	Decreased GFR, Albuminuria
Idiopathic focal sclerosis	G2	A3	Albuminuria
Kidney transplant recipient	G2	A1	History of kidney transplantation
Polycystic kidney disease	G2	A1	Imaging abnormality
Vesicoureteral reflex	G1	A1	Imaging abnormality
Distal renal tubular acidosis	G1	A1	Electrolyte abnormalities
Hypertensive kidney disease	G4	A2	Decreased GFR, Albuminuria
CKD presumed due to diabetes and hypertension	G4	A1	Decreased GFR
CKD presumed due to diabetes and hypertension	G2	A3	Albuminuria
CKD presumed due to diabetes and hypertension	G3a	A1	Decreased GFR
CKD cause unknown	G3a	A1	Decreased GFR
Abbreviations: CGA, Cause, GFR category and albuminuria category; CKD, chronic kidney disease; GFR, glomerular filtration rate. Note: Patients above the thick horizontal line are likely to be encountered in nephrology practice. Patients below the thick horizontal line are likely to be encountered in primary care practice and in nephrology practice.