NICE vs SIGN: Management of Chronic Kidney Disease (2025)

This guide provides a comparative overview of the National Institute for Health and Care Excellence (NICE) Clinical Guideline [NG203] (published 2021, updated September 2023) and the Scottish Intercollegiate Guidelines Network (SIGN) Guideline 167 (published 2024) for the management of chronic kidney disease (CKD) in adults. It is designed to help clinicians understand the nuances between these two authoritative UK guidelines to inform practice.

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Diagnosis and Staging of CKD

Both guidelines agree on the fundamental principles of CKD diagnosis, which relies on persistent abnormalities of kidney structure or function for more than 3 months.

NICE NG203

• Staging: Uses the KDIGO (Kidney Disease: Improving Global Outcomes) classification, combining GFR categories (G1-G5) and albuminuria categories (A1-A3). This two-dimensional risk stratification is central to its approach.
• Diagnostic Criteria: Diagnosis requires either a GFR <60 ml/min/1.73m² (G3a-G5) or evidence of kidney damage (e.g., albuminuria, haematuria, histological abnormalities, structural anomalies) for >3 months.
• Key Emphasis: Strong focus on the albumin-to-creatinine ratio (ACR) as the primary marker for albuminuria. The guideline provides detailed risk tables based on GFR and ACR to predict the risk of adverse outcomes.

SIGN 167

• Staging: Also adopts the KDIGO classification system, acknowledging the importance of both GFR and albuminuria.
• Diagnostic Criteria: Largely aligns with NICE but places a distinct, practical emphasis on the context of the result. It explicitly advises considering whether the finding of reduced GFR is acute, chronic, or acute-on-chronic at the point of discovery.
• Key Emphasis: Highlights the use of both ACR and protein-to-creatinine ratio (PCR) for quantifying proteinuria, providing more explicit guidance on when PCR may be used.

Key Difference

The core difference is one of framing. NICE provides a highly structured, risk-stratified algorithm, while SIGN reinforces the need for clinical judgement at the initial diagnostic stage, particularly in distinguishing acute from chronic deterioration.

Treatment and Management

Both guidelines strongly advocate for a multifaceted approach addressing blood pressure, cardiovascular risk, and metabolic complications.

Pharmacological Management

• Blood Pressure Control:
  • NICE: Recommends a target of <140/90 mmHg for most patients, and <130/80 mmHg for those with ACR ≥70 mg/mmol. First-line treatment is an ACE inhibitor (ACEi) or an angiotensin receptor blocker (ARB).
  • SIGN: Recommends a target of <140/90 mmHg. For patients with diabetes or significant proteinuria (ACR >70 mg/mmol), a lower target of <130/80 mmHg may be considered. Also recommends ACEi/ARB as first-line.
• SGLT2 Inhibitors: This is a major area of alignment, reflecting recent evidence.
  • Both guidelines recommend SGLT2 inhibitors for patients with CKD and type 2 diabetes, regardless of glycaemic control, to reduce the risk of CKD progression and cardiovascular events.
  • NICE extends this recommendation to non-diabetic CKD (with an eGFR ≥25 ml/min/1.73m² and ACR ≥22.6 mg/mmol) as an option to reduce the risk of end-stage kidney disease, hospitalisation, and death.
  • SIGN also supports their use in non-diabetic CKD, aligning closely with NICE, making this a standard of care.

Non-Pharmacological Management and Monitoring

• NICE provides very specific, tabulated monitoring frequencies based on CKD stage and stability.
• SIGN offers more flexible, principle-based advice, suggesting monitoring frequency should be individualised based on the rate of progression, comorbidity, and treatment changes.

Key Difference

The treatment protocols are highly congruent, especially regarding SGLT2 inhibitors. The main distinction lies in the precision of monitoring schedules (NICE) versus individualised flexibility (SIGN).

Special Situations

Acute Kidney Injury (AKI) in CKD

• SIGN dedicates significant attention to this, providing clear recommendations on investigating the cause of AKI in people with known CKD and managing the increased risk associated with nephrotoxic agents (e.g., NSAIDs, iodinated contrast).
• NICE covers this within its broader AKI guideline (CG169) rather than extensively within the CKD guideline itself.

Polycystic Kidney Disease (ADPKD)

• SIGN includes specific recommendations for ADPKD, including monitoring and discussion of treatment with tolvaptan.
• NICE addresses tolvaptan for ADPKD in a separate technology appraisal guidance (TA358).

Practical Takeaway

SIGN 167 is more self-contained for managing common complications within the CKD population, while NICE often signposts to other, condition-specific guidelines.

Practical Clinical Flow: A Synthesis

For a UK clinician, a practical synthesis of both guidelines would be:

1. Identify: Detect reduced eGFR or kidney damage on testing. Use SIGN's emphasis to determine if this is acute or chronic.
2. Stage & Stratify Risk: Use the KDIGO grid (as per both guidelines) with eGFR and ACR to determine the patient's risk category.
3. Investigate: Perform baseline investigations (urinalysis, urine microscopy, renal ultrasound if indicated) to identify the cause.
4. Treat: Implement lifestyle advice. Start ACEi/ARB for hypertension/proteinuria. Strongly consider SGLT2 inhibitors in eligible patients (with and without diabetes). Manage cardiovascular risk.
5. Monitor & Refer: Follow a monitoring schedule (using NICE's frequency as a safe benchmark, adapted per SIGN's advice based on individual patient factors). Refer to nephrology based on agreed criteria (e.g., rapidly progressing CKD, uncertain aetiology, CKD G4/G5).

Frequently Asked Questions (FAQs)

1. Which guideline should I follow in Scotland or England?

Clinicians in Scotland are expected to follow SIGN guidance, while those in England and Wales follow NICE. However, the 2024 SIGN guideline actively incorporates and comments on the 2023 NICE update, creating a high degree of harmony. There are no major conflicts that would lead to significantly different patient outcomes.

2. What is the single biggest difference between them?

The most noticeable difference is the presentation style and emphasis. NICE is highly algorithmic and tabulated, ideal for structured care pathways and QOF (Quality and Outcomes Framework). SIGN is more narrative, emphasising clinical reasoning and the integration of CKD management within a broader patient context.

3. Are the referral criteria to nephrology the same?

Yes, they are very similar. Both list criteria such as AKI, rapid progression, CKD G4/G5, significant proteinuria, resistant hypertension, and suspected rare or systemic disease. The specific thresholds (e.g., for ACR) are identical.

4. How do they handle drug dosing in CKD?

Both guidelines stress the importance of drug dose adjustment based on eGFR. NICE provides a link to its separate ‘Medicines Optimisation’ guideline. SIGN incorporates more direct, practical advice on common drug classes (e.g., metformin, direct oral anticoagulants) within the CKD guideline text.

5. Is there a difference in the approach to patient information and shared decision-making?

Both prioritise patient education. NICE includes specific recommendations on the content of discussions (e.g., prognosis, treatment options). SIGN places a particularly strong emphasis on supported self-management and the use of resources like the 'My Kidneys' platform to empower patients.

Source Links

• NICE NG203 (2021, updated Sept 2023): Chronic kidney disease: assessment and management
• SIGN 167 (2024): Management of chronic kidney disease

Summary and Key Takeaways

• Alignment: NICE and SIGN are fundamentally aligned on the core principles of CKD diagnosis, risk stratification, and key treatments, especially the use of SGLT2 inhibitors.
• Style: NICE is more algorithmic; SIGN is more narrative and emphasises initial clinical judgement.
• Scope: SIGN 167 is more self-contained for special situations like AKI and ADPKD.
• Practical Implication: For most day-to-day decisions, the guidelines are interchangeable. Using the structured approach of NICE supplemented by the clinical reasoning prompts in SIGN represents a robust strategy for any UK clinician.