Do nephrologists agree on who should be referred to them?
Not surprisingly, no they do not [“great .. thanks guys”. CKDEx Ed]. These are the main guidelines currently used.
KDIGO (USA) 2013 referral criteria
US KDIGO guidelines (2013) recommend that adult patients with CKD be referred to a nephrologist, regardless of age (if ˃20 years), when any one of the following conditions are present:
- Persistent eGFR <30 mL/min
- Urinary albumin:creatinine ratio (uACR) > 34 mg/mmol (>300 mg/g)
- Abrupt or rapidly progressive deterioration of kidney function
- Treatment-resistant hypertension
- Red blood cell casts in urine (microscopy)
- Blood potassium high (or low)
- CKD-associated anaemia
- Hereditary CKD or polycystic kidney disease (PKD) is suspected
- Recurrent/extensive nephrolithiasis (kidney stones).
The advantages of the KDIGO criteria are the wide awareness and usage of these guidelines, and also the explicit description of reasons for referral. The disadvantages are that the eGFR thresholds for referral are neither age-adapted nor based on specific risks.
National Institute for Health and Clinical Excellence (NICE, for UK) 2021 referral criteria
The UK’s 2008-14 NICE guidelines recommendation of referring when eGFR is <30 mL/min/ 1.73 m2 (CKD Stages 4-5) were substituted in the 2021 guidelines by a 5-year risk of needing renal replacement therapy of ˃5% (measured using the four-variable Kidney Failure Risk Equation, KFRE).
Other reasons for referral include:
- Marked proteinuria – uACR ≥70 mg/mmol, unless known to be caused by diabetes already appropriately treated, or uACR ≥30 mg/mmol together with haematuria
- Sustained decrease of eGFR of ≥15 mL/min/1.73 m2 per year
- Hypertension that remains poorly controlled despite the use of at least four antihypertensive drugs
- People with or suspected of having rare or genetic causes of CKD
- Patients with suspected renal artery stenosis.
The advantages of the NICE criteria are that the KFRE is included. The disadvantages are that hyperkalaemia and anaemia are not included and the eGFR thresholds are not age-adapted.
Other guidelines, referral criteria
Guidelines such as the US National Kidney Foundation (NKF; Kidney Disease Outcomes Quality Initiative), Caring for Australasians with Renal Impairment (CARI), American Diabetes Association of 2022 and European guidelines, in general recommend that patients with GFR <30 mL/min/ 1.73 m2 (CKD Stages 4–5), regardless of the age of the patient, should be referred to a nephrologist, amongst other causes.
But the French guidelines (Haute Autorité de Sante) recommend a higher cut-off value of 45 mL/min/1.73 m2. The different main guidelines that address referral recommendations from primary care to nephrologists are shown in the table below.
Recommendation summary of different guidelines comparing criteria for referral to nephrologists
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KDIGO: Kidney Disease: Improving Global Outcomes 2013; NICE: National Institute for Health and Clinical Excellence 2021; SEN: Sociedad Española Nefrologia 2022 (Spanish Society of Nephrology); CARI: Caring for Australasians & New Zealanders with Kidney Impairment; Sweden: Southern Health Region.
Summary
Other resource
Last Reviewed on 2 April 2024