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
CauseGFR categoryAlbuminuria categoryCriterion for CKD
Diabetic kidney diseaseG5A3Decreased GFR, Albuminuria
Idiopathic focal sclerosisG2A3Albuminuria
Kidney transplant recipientG2A1History of kidney transplantation
Polycystic kidney diseaseG2A1Imaging abnormality
Vesicoureteral reflexG1A1Imaging abnormality
Distal renal tubular acidosisG1A1Electrolyte abnormalities
Hypertensive kidney diseaseG4A2Decreased GFR, Albuminuria
CKD presumed due to diabetes and hypertensionG4A1Decreased GFR
CKD presumed due to diabetes and hypertensionG2A3Albuminuria
CKD presumed due to diabetes and hypertensionG3aA1Decreased GFR
CKD cause unknownG3aA1Decreased 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.