CKD Stage Classification for GFR of 88 mL/min/1.73 m²
A GFR of 88 mL/min/1.73 m² falls into Stage 2 CKD if there is evidence of kidney damage, or represents normal kidney function if no kidney damage is present. 1
Understanding the Classification
The critical distinction here is that GFR alone does not define early-stage CKD—you must also document kidney damage. 1, 2
Stage 2 CKD Criteria (GFR 60-89 mL/min/1.73 m²)
Stage 2 CKD requires both of the following 1:
- GFR between 60-89 mL/min/1.73 m² (which includes your patient's GFR of 88)
- Evidence of kidney damage persisting for ≥3 months, defined by:
If No Kidney Damage is Present
Without evidence of kidney damage, a GFR of 88 mL/min/1.73 m² does not constitute CKD—this represents mildly reduced but essentially normal kidney function. 3 The patient would be classified as having normal kidney function (Stage 0 or no CKD). 1
Clinical Pitfalls to Avoid
Do not diagnose CKD based solely on a single GFR measurement in the 60-89 range. 3 This is a widespread misunderstanding that can lead to inappropriate labeling of patients, with negative consequences for insurance and patient anxiety. 3
The 3-month persistence requirement is mandatory—transient decreases in GFR do not qualify as CKD. 1, 2 You must document either sustained GFR reduction or persistent markers of kidney damage over this timeframe. 2
Practical Assessment Algorithm
To properly classify this patient 1, 2:
- Check for proteinuria: Obtain spot urine albumin-to-creatinine ratio (threshold ≥30 mg/g) 2
- Review imaging: Look for structural kidney abnormalities 1
- Verify persistence: Confirm abnormalities persist for ≥3 months 1, 2
- If positive: Classify as Stage 2 CKD
- If negative: Document as normal kidney function, not CKD
Stage 1 CKD (GFR ≥90 mL/min/1.73 m²) also requires evidence of kidney damage, so a GFR of 88 technically falls just below this threshold into the Stage 2 range when damage is present. 1