List diagnostic criteria.
Criteria for chronic kidney disease (CKD) include the persistence of eGFR < 60 mL/min/1.73 m2 (≥ G3a) and/or of any of the following markers of kidney damage for > 3 months:
Albuminuria: e.g., urine albumin-to-creatinine ratio (UACR) > 30 mg/g (≥ A2)
Urine sediment abnormalities: e.g., hematuria
Abnormalities due to tubulointerstitial dysfunction, e.g.:
Electrolyte and acid-base imbalances
Retention of nitrogenous wastes
Reduced production of erythropoietin, 1,25-dihydroxyvitamin D, and/or renin
Histological abnormalities on biopsy
Imaging showing structural abnormalities: e.g., polycystic kidney disease
History of renal transplant
CKD progression is the presence of either of the following:
A decline in renal function, leading to a change in eGFR category
A sustained decline in eGFR of > 5 mL/min/1.73 m2 per year
End-stage renal disease (ESRD) 
Irreversible kidney dysfunction with eGFR < 15 mL/min/1.73 m2
AND manifestations of uremia requiring chronic renal replacement therapy with either dialysis (hemofiltration or hemodiafiltration) or renal transplantation
Describe the CGA classification of CKD.
CKD is classified according to the cause, eGFR category, and albuminuria category; this is referred to as the CGA classification.
Standardized documentation of CKD stages
Identification of CKD progression
Determination of the frequency of patient monitoring
Interpretation: Higher stages correlate with a poorer prognosis. 
Increased risk of CKD progression and mortality (e.g., all-cause mortality, cardiovascular mortality)
Increased risk of developing complications (e.g., AKI, CKD-mineral and bone disorder)
Systemic vs. primary cause: Determine if kidney disease is associated with a systemic disease (e.g., diabetes) or if it is primary kidney disease (e.g., polycystic kidney disease).
Location: Determine the location (presumed or confirmed) of the damage within the kidney.
Cystic and congenital