The grid below is a “Risk Map” for chronic kidney disease (CKD) that reflects prognosis, recommended frequency of monitoring, and indications for nephrology referral. To see case studies, click on a colored box in the grid below.
G1 | Normal or High ≥ 90
A1 | Normal to mildly increased < 30 mg/g (< 3 mg/mmol)
A 44-year old woman with autosomal dominant polycystic kidney disease presents to your clinic for routine follow-up. Since her last follow-up six months ago, she has had some back discomfort. Her blood pressure is 128/76. Her eGFR has remained stable at 110 ml/min/1.73 m2, and her ACR shows 20 mg/g of albuminuria. Based on the heat “CKD Risk Map,” you also know that: 1) her CKD can be classified as G1/A1; 2) her risk of progression is low; 3) she should be monitored by you at least once per year.
G1 | Normal or High ≥ 90
A2 | Moderately increased 30 – 299 mg/g (3 – 29 mg/mmol)
A 55-year old man with a history of long-standing hypertension presents to clinic for routine follow-up. His blood pressure is 150/80 mm Hg. His lab results show that his eGFR and ACR are stable at 96 mL/min/1.73 m2 and 260 mg/g, respectively. Based on the “CKD Risk Map,” you know that: 1) his CKD can be classified as G1/A2; 2) he has a moderately increased risk of progression; and 3) he should be monitored at least once per year..
G1 | Normal or High ≥ 90
A3 | Severly increased ≥ 300 mg/g (≥ 30 mg/mmol)
A 27-year old woman has a history of type 1 diabetes complicated by mild diabetic retinopathy and lower extremity neuropathy. She presents to your clinic for routine follow-up. Since her last follow-up four months ago, her hemoglobin A1c has improved from 8.4% to 7.9%. Her eGFR remains stable at 92 ml/min/1.73 m2, and her ACR remains elevated at 416 mg/g despite ACE-inhibitor therapy. Based on the “CKD Risk Map,” you know that: 1) her CKD can be classified as G1/A3; 2) her risk of progressing to kidney failure is high; 3) referral to a nephrologist is recommended; and 4) she should be monitored at least twice per year.
G2 | Mildly Decreased 60 – 89
A1 | Normal to mildly increased < 30 mg/g (< 3 mg/mmol)
A 40-year old woman was recently diagnosed with hypertension. She has a strong family history of hypertension and chronic kidney disease. She presents to clinic for a new patient evaluation. Her lab results show that her eGFR is 89 mL/min/1.73 m2, and her ACR is 16 mg/g. These are consistent with lab results documented one year ago. Based on the “CKD Risk Map,” you know that: 1) her CKD is classified as G2/A1; 2) her risk of progressing to kidney failure is low; and 3) she should be monitored at least once per year.
G2 | Mildly Decreased 60 – 89
A2 | Moderately increased 30 – 299 mg/g (3 – 29 mg/mmol)
A 55-year old obese man has a history of hypertension for which he takes a diuretic and ACE-inhibitor. He was hospitalized for acute kidney injury (AKI) in the setting of frequent ibuprofen use six months ago. His eGFR prior to his AKI was >90 ml/min/1.73 m2; his prior ACR test revealed no albuminuria. However, his eGFR has now stabilized to 65 ml/min/1.73 m2, and he has had persistent albuminuria of 150 mg/g. Based on the “CKD Risk Map,” you know that: 1) his CKD can be classified as G2/A2; 2) his risk of progression is moderate; and 4) he should be monitored by you at least once per year.
G2 | Mildly Decreased 60 – 89
A3 | Severly increased ≥ 300 mg/g (≥ 30 mg/mmol)
A 66-year old woman with longstanding type 2 diabetes and obesity presents to your clinic for routine follow-up. She has a history of diabetic retinopathy for which she recently underwent treatment. Since her last follow-up 6 months ago, her hemoglobin A1c remains elevated at 8.9%. Her eGFR is stable at 64 mL/min/1.73 m2, and her ACR is elevated at 970 mg/g. Based on the “CKD Risk Map,” you know that: 1) her CKD can be classified as G2/A3; 2) her risk of progressing to kidney failure is moderately increased; 3) referral to a nephrologist is recommended; and 4) she should be monitored at least twice per year.
G3a | Mildly to moderately decreased 45 – 59
A1 | Normal to mildly increased < 30 mg/g (< 3 mg/mmol)
A 70-year old woman with a history of coronary heart disease status post percutaneous coronary intervention 10 years ago, hypertension, and remote 50 pack-year history of cigarette smoking presents to your clinic for a general evaluation. Her blood pressure in clinic is 160/70. Her eGFR based on her serum cystatin C level of 1.4 mg/L is 45 ml/min/1.73 m2, which is lower than her last eGFR of
48 ml/min/1.73 m2 two years ago. Her ACR remained low at 12 mg/g. Based on the “CKD Risk Map,” you know that: 1) her CKD can be classified as G3a/A1; 2) her risk of progression is moderately increased; and 3) she should be monitored at least once per year.
G3a | Mildly to moderately decreased 45 – 59
A2 | Moderately increased 30 – 299 mg/g (3 – 29 mg/mmol)
A 60-year old man with long-standing hypertension has been a patient in your clinic for one year. Within that year, his eGFR results have remained 50 mL/min/1.73 m2. His albuminuria is 50 mg/g. On exam, he has a blood pressure of 156/92. He is obese. The remainder of his exam is unremarkable. Based on the “CKD Risk Map,” you also know that: 1) his CKD can be classified as G3a/A2; 2) his risk of CKD progression is high; and 3) he should be monitored by you at least twice per year.
G3a | Mildly to moderately decreased 45 – 59
A3 | Severly increased ≥ 300 mg/g (≥ 30 mg/mmol)
A 24-year old man with a history of ureteral reflux and consequent chronic kidney disease presents to clinic for routine follow-up. Since his last follow-up, the patient notes adherence with his self-catheterization. His labs reveal that his eGFR and ACR are stable at 50 mL/min/1.73 m2 and 680 mg/g, respectively. Based on the “CKD Risk Map,” you know that: 1) his CKD can be classified as G3a/ A3; 2) his risk of progressing to kidney failure is very high; 3) referral to a nephrologist is recommended; and 4) he should be monitored at least three times per year.
G3b | Moderately to severely decreased 30 – 44
A1 | Normal to mildly increased 30 – 299 mg/g (3 – 29 mg/mmol)
A 76-year old man with polycystic kidney disease, hypertension, and mild aortic valve regurgitation presents to clinic for routine follow-up. Since his last visit, the patient notes transient gross hematuria and mild back discomfort. His labs demonstrate that his eGFR is stable at 35 mL/min/1.73 m2, and his ACR is <30 mg/g. Based on the “CKD Risk Map,” you know that: 1) his CKD can be classified as G3b/ A3; 2) his risk of progressing to kidney failure is moderately increased; and 3) he should be monitored at least twice per year.
G3b | Moderately to severely decreased 30 – 44
A2 | Moderately increased 30 – 299 mg/g (3 – 29 mg/mmol)
A 44-year old woman has a history of chronic back pain for which she regularly takes non-steroidal anti-inflammatory drugs. Unfortunately as a result, she has developed chronic kidney disease. Since her last visit, the patient admits to ongoing occasional use of these drugs. Her most recent labs demonstrate her eGFR to be 36 ml/min/1.73 m2, and her ACR to be 280 mg/g which are slightly worse from her labs six months ago. Based on the “CKD Risk Map,” you know that: 1) her CKD can be classified as G3b/A2; 2) her risk of progressing to kidney failure is very high; 3) referral to a nephrologist is recommended; and 4) she should be monitored at least three times per year.
G3b | Moderately to severely decreased 30 – 44
A3 | Normal to mildly increased < 300 mg/g (< 30 mg/mmol)
A 53-year old man with type 2 diabetes and hypertension presents to your clinic for follow-up. His eGFR has been 40 ml/min/1.73 m2 for the past two years. His ACR test shows he has 380 mg/g of albuminuria. On exam, his blood pressure is 150/90 with a heart rate of 78 beats per min. His BMI is 32 kg/ m2. He has 1+ pitting edema along his lower extremities and decreased sensation along the dorsal aspect of his feet. Based on the “CKD Risk Map,” you know that: 1) his CKD can be classified as G3b/A3; 2) his risk of progressing to kidney failure is very high; 3) referral to a nephrologist is recommended; and 4) he should be monitored at least three times per year.
G4 | Severely Decreased 15 – 29
A1 | Normal to mildly increased < 30 mg/g (< 3 mg/mmol)
A 65-year old man with a history of gouty arthritis and long-standing hypertension presents to clinic with a painful right great toe. You prescribe him a short course of steroids and initiate allopurinol for his gout flare. His labs results from that visit showed that his eGFR and ACR remained stable at 18 ml/min/1.73 m2 and 25 mg/g, respectively. Based on the “CKD Risk Map,” you know that: 1) his CKD can be classified as G4/A1; 2) his risk of progression is very high; 3) referral to a nephrologist is recommended; and 4) he should be monitored at least three times per year.
G4 | Severely Decreased 15 – 29
A2 | Moderately increased 30 – 299 mg/g (3 – 29 mg/mmol)
A 62-year old man has a remote history of post-infectious glomerulonephritis. As a result of this, he was left with chronic kidney disease and proteinuria for which he was been receiving an ACE-inhibitor. His blood pressure during his clinic visit was 128/76 mm Hg. His lab results show that his eGFR and ACR are stable at 27 ml/min/1.73m2 and 290 mg/g, respectively. Based on the “CKD Risk Map,” you know that: 1) his CKD can be classified as G4/A2; 2) his risk of progressing to kidney failure is very high; 3) referral to a nephrologist is recommended; and 4) he should be monitored at least three times per year.
G4 | Severely Decreased 15 – 29
A3 | Severely increased ≥ 300 mg/g (≥ 30 mg/mmol)
A 35-year old woman presents with type 1 diabetes, hypertension, and dyslipidemia. She is on an ACE-inhibitor with good blood pressure control. Within the past three years, her eGFR has dropped from 46 mL/min/1.73 m2 to 28 mL/min/1.73 m2. Her current albuminuria consistently remains ≥300 mg/g. Her lab results reveal that she has recently developed CKD-related mineral and bone disorder (CKD-MBD), with an intact PTH of 220 pg/ml and serum phosphorus of 4.8 mg/dl. Based on the “CKD Risk Map,” you know that: 1) her CKD can be classified as G4/A3; 2) her risk of progression is very high; 3) referral to a nephrologist is recommended; and 4) she should be monitored four or more times per year.
G5 | Kidney Failure < 15
A1 | Normal to mildly increased < 30 mg/g (< 3 mg/mmol)
A 62-year old woman presents to your clinic for routine follow-up. She has a history of right renal cell carcinoma status post a right nephrectomy one year ago. She also has a history of hyperlipidemia, coronary artery disease, and peripheral arterial disease. Unfortunately, her chronic kidney disease has progressively worsened over the last year. She denies any uremic symptoms. Her lab results in clinic showed that her eGFR was 12 mL/min/1.73 m2, and her ACR was 22 mg/g. Based on the “CKD Risk Map,” you know that: 1) her CKD can be classified as G5/A1; 2) she is at highest risk of progressing to kidney failure; 3) referral to a nephrologist is recommended; and 4) she should be monitored at least four times per year.
G5 | Kidney Failure < 15
A2 | Moderately increased 30 – 299 mg/g (3 – 29 mg/mmol)
A 58-year old man with a history of hypertension, type 2 diabetes, and coronary artery disease with consequent congestive heart failure presents to clinic for follow-up after his recent hospitalization for volume overload. Approximately one week after his hospitalization, his labs showed his eGFR to be at his baseline of 14 mL/min/1.73 m2, and his ACR to be stable at 240 mg/g. Based on the “CKD Risk Map,” you know that: 1) his CKD can be classified as G5/A2; 2) he is at highest risk of progressing to kidney failure; 3) referral to a nephrologist is recommended; and 4) he should be monitored at least four times per year.
G5 | Severely Decreased < 15
A3 | Severely increased ≥ 300 mg/g (≥ 30 mg/mmol)
A 38-year old woman with systemic lupus erythematosus presents to clinic for routine follow-up. She has a history of advanced kidney disease attributed to lupus nephritis and hypertension. Since her last visit, she reports some mild fatigue and denies any nausea or weight loss. Her labs revealed an eGFR of 14 mL/min/1.73 m2 and an ACR of 1200 mg/g. Based on the “CKD Risk Map,” you know that: 1) her CKD can be classified as G5/A3; 2) she is at highest risk of progressing to kidney failure; 3) referral to a nephrologist is recommended; and 4) she should be monitored at least four times per year.
Adapted with permission from KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int. 2013;Suppl.3:1-150.
Key to Figure:
Colors: Represents the risk for progression, morbidity and mortality by color from best to worst. Green: low risk (if no other markers of kidney disease, no CKD); Yellow: moderately increased risk; Orange: high risk; Red, very high risk; Deep red, highest risk.
Numbers: Represent a recommendation for the number of times per year the patient should be monitored.
Refer: Indicates that nephrology referral and services are recommended.
*Referring clinicians may wish to discuss with their nephrology service depending on local arrangements regarding monitoring or referral.
