Does a patient need to have an estimated Glomerular Filtration Rate (eGFR) of less than 60 ml/min/1.73m² to be diagnosed with Chronic Kidney Disease (CKD), or can a diagnosis be made with an eGFR of 60-89 ml/min/1.73m²?

CKD Diagnosis: eGFR Thresholds and Kidney Damage Criteria

CKD can be diagnosed with an eGFR of 60-89 mL/min/1.73 m² if there is evidence of kidney damage present for at least 3 months, but eGFR <60 mL/min/1.73 m² alone is sufficient to diagnose CKD regardless of whether kidney damage markers are present. 1

Understanding the Two-Part Definition

CKD requires either of the following criteria persisting for ≥3 months: 1, 2

• eGFR <60 mL/min/1.73 m² (with or without kidney damage markers)
• Evidence of kidney damage (with any eGFR level, including ≥60)

When eGFR is 60-89 mL/min/1.73 m² (Stage 2 CKD)

You must have documented kidney damage to diagnose CKD at this eGFR range. 1 Acceptable markers of kidney damage include: 1, 2

• Albuminuria: UACR ≥30 mg/g (most common marker)
• Pathological abnormalities on kidney biopsy
• Imaging abnormalities: structural changes, cysts, or other renal abnormalities on ultrasound/CT
• Urine abnormalities: persistent hematuria or other abnormal findings
• History of kidney transplantation

Without any of these damage markers, an eGFR of 60-89 mL/min/1.73 m² does not constitute CKD—it may represent normal kidney function, particularly in younger individuals. 1, 3

When eGFR is <60 mL/min/1.73 m² (Stage 3-5 CKD)

No additional markers are required. 1 An eGFR persistently <60 mL/min/1.73 m² for ≥3 months is diagnostic of CKD by itself, regardless of whether albuminuria or other damage markers are present. 2

Critical Confirmation Strategy for Borderline Cases

When creatinine-based eGFR is 45-59 mL/min/1.73 m² (Stage 3a) without other kidney damage markers, measure cystatin C to confirm true CKD. 4, 5 This is essential because:

• Approximately 23% of patients with creatinine-based eGFR 45-59 actually have normal kidney function when confirmed with cystatin C 4
• If cystatin C-based eGFR is ≥60 mL/min/1.73 m², CKD diagnosis is not confirmed 4
• If cystatin C-based eGFR is <60 mL/min/1.73 m², CKD diagnosis is confirmed 4
• The combined creatinine-cystatin C equation (eGFRcreat-cys) provides 94.9% accuracy and should guide clinical decisions 4, 5

Common Pitfall to Avoid

Do not diagnose CKD in patients with eGFR 60-89 mL/min/1.73 m² who lack evidence of kidney damage. 3 Misdiagnosing CKD has negative consequences including insurance implications, unnecessary patient anxiety, and inappropriate nephrology referrals. 3 Always verify that patients with Stage 1-2 CKD have documented albuminuria, structural abnormalities, or other damage markers before assigning the diagnosis. 1, 2

Staging Algorithm

Once CKD is confirmed, stage according to eGFR: 1

• Stage 1: eGFR ≥90 (requires kidney damage markers)
• Stage 2: eGFR 60-89 (requires kidney damage markers)
• Stage 3a: eGFR 45-59 (no damage markers required)
• Stage 3b: eGFR 30-44 (no damage markers required)
• Stage 4: eGFR 15-29 (no damage markers required)
• Stage 5: eGFR <15 or dialysis (no damage markers required)