Yes, an eGFR of 28 mL/min/1.73 m² is classified as CKD Stage 4
An estimated glomerular filtration rate of 28 mL/min/1.73 m² falls within the range of 15-29 mL/min/1.73 m², which defines chronic kidney disease Stage 4 (severe decrease in GFR). 1, 2
CKD Staging Classification
The internationally accepted staging system defines CKD stages based on eGFR levels 2:
- Stage 1: eGFR ≥90 mL/min/1.73 m² with kidney damage
- Stage 2: eGFR 60-89 mL/min/1.73 m² with kidney damage
- Stage 3a: eGFR 45-59 mL/min/1.73 m²
- Stage 3b: eGFR 30-44 mL/min/1.73 m²
- Stage 4: eGFR 15-29 mL/min/1.73 m² (severe decrease)
- Stage 5: eGFR <15 mL/min/1.73 m² (kidney failure)
Your eGFR of 28 mL/min/1.73 m² places you squarely in Stage 4, representing severe kidney function impairment with loss of approximately 75% of normal kidney function 2.
Critical Clinical Implications at Stage 4
At this stage, you require nephrology referral and preparation for kidney replacement therapy. 2 The guidelines explicitly recommend that a nephrologist should participate in care when eGFR falls below 30 mL/min/1.73 m² 2.
Immediate Actions Required:
- Nephrology consultation: Mandatory at this stage for co-management 2
- Preparation for kidney replacement therapy: Should begin now, before reaching Stage 5 2
- Evaluation of complications: Anemia, bone disease, malnutrition, neuropathy, and cardiovascular risk all increase significantly at this level of kidney function 2
- Medication adjustments: All drug dosing must be adjusted for eGFR <30 mL/min/1.73 m² 3, 2
Important Medication Considerations at eGFR 28:
For diabetic patients specifically 3:
- Metformin: Contraindicated—must be discontinued 3
- SGLT2 inhibitors: Can be initiated if eGFR ≥20 mL/min/1.73 m² 4, 5
- Insulin requirements: Reduce total daily dose by 35-40% for type 1 diabetes, 50% for type 2 diabetes 3
- DPP-4 inhibitors: Require significant dose reductions (e.g., sitagliptin 25 mg daily maximum) 3
Common Pitfalls to Avoid
Do not delay nephrology referral. Late referral (shortly before dialysis) is associated with increased mortality after dialysis initiation 2. At eGFR 28, you are already in the window where preparation for kidney replacement therapy should be underway.
Do not continue nephrotoxic medications without careful review. This includes NSAIDs, certain antibiotics, and contrast agents, which pose significantly higher risk at this level of kidney function 6.
Do not assume the eGFR alone tells the complete story. Check for albuminuria (urine albumin-to-creatinine ratio), as the combination of low eGFR and proteinuria significantly increases risk of progression and cardiovascular events 1, 4.
Cardiovascular Risk Consideration
Patients with CKD Stage 4 should be considered in the highest risk group for cardiovascular disease events 2. Cardiovascular events are actually more common than progression to kidney failure in CKD patients, making aggressive cardiovascular risk management essential 2.