2 Implementation: getting started

This section highlights some important changes to practice that may result from implementing this guideline, which were identified at the time of publication in July 2014. With input from stakeholders, experts and health professionals, 3 areas were identified that may have a big impact on practice or could be challenging to implement. However, other changes to practice may be needed to fully implement the guideline.

Primary care providers, laboratory services and their respective commissioners may be particularly affected by these changes.

2.1 Calculating estimates of creatinine-based glomerular filtration rate (GFR)

See recommendation 1.1.2.

Potential impact of implementation

The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine equation is more accurate than the Modification of Diet in Renal Disease (MDRD) Study equation, is less biased at a GFR of more than 60 ml/min/1.73 m2 and performs better in people aged 75 years and over. The use of the MDRD Study equation may over-diagnose CKD. Using the CKD-EPI equation instead could benefit patients and clinicians by reducing unnecessary appointments, reducing patients' concerns and reducing the overall burden of CKD in the population.

Challenges for implementation

  • Laboratories using the MDRD Study equation to estimate GFR may need to change their practice.

  • Using the CKD-EPI creatinine equation to estimate GFR may make it difficult to assess trends over time in people with previous GFR estimates calculated using other equations.

  • Laboratories may need to update their software to include the CKD‑EPI creatinine equation so that it is used automatically.

Support for implementation

  • Online tools can be used to give estimates of GFR using the MDRD Study equation (for example, those produced by the UK Renal Association the National Kidney Disease Education Program and at MDRD.com), for comparison with CKD‑EPI results.

  • The Association of Clinical Biochemistry and Laboratory Medicine, Lab Tests Online UK and the UK National External Quality Assessment Service are raising awareness of the change and include it in laboratory inspection frameworks.

  • Local clinical commissioning groups could contact their local laboratory to help ensure that this change is incorporated into practice.

2.2 Using cystatin C-based estimates of GFR

See recommendation 1.1.14.

Potential impact of implementation

Estimates of GFR (eGFR) based on serum cystatin C have a higher specificity for significant disease outcomes than those based on serum creatinine. For people with a borderline diagnosis, eGFRcystatinC is an additional diagnostic tool that may reduce over diagnosis. Using this tool may result in a significant proportion of people classified as having stage 3 CKD being reclassified as not having CKD (G1A1 or G2A1). This could benefit patients and clinicians by reducing unnecessary appointments, reducing patients' concerns and reducing the overall burden of CKD in the population. This additional test may have a cost impact, but there will be financial benefits, with fewer diagnoses leading to reduced management costs.

Challenges for implementation

  • Cystatin C testing is a new recommendation and so primary care teams may not be aware of when to request this test.

  • Cystatin C testing may not be widely available. Laboratories may need to invest in training and, in some cases, equipment.

  • Using cystatin C as an additional test will have a financial impact. Based on estimated demand, decisions might need to be made about whether all laboratories or designated laboratories offer this test. Costs will vary, and should be assessed locally depending on the model of provision.

Support for implementation

  • This test only needs to be performed in a defined population (as recommended in 1.1.14) and generally only once for each person.

  • The assay for cystatin C can be performed using existing analysers.

  • Clinicians are likely to welcome the introduction of a more accurate test for eGFR because many of them doubt the previously recommended diagnostic criteria for early CKD.

  • See the NICE costing statement for further information and advice on costs.

2.3 Classifying chronic kidney disease

See recommendation 1.2.1.

Potential impact of implementation

Both albumin:creatinine ratio (ACR) and GFR indicate the risk of adverse events and CKD progression, but when used together, risk stratification and accuracy is increased. More accurate classification of CKD may lead to more targeted treatment and monitoring.

Challenges for implementation

  • Testing for both eGFR and ACR may add extra burden and cost to diagnosis and monitoring.

  • The addition of ACR makes classification of CKD more complex and those using CKD stages will need to change their practice.

Support for implementation

  • The classification table shows how the GFR categories (G1–G5, which have the same GFR thresholds as the CKD stages 1–5 recommended previously), and ACR categories (A1–A3) should be combined, for example:

    • A person with an eGFR of 25 ml/min/1.73 m2 and an ACR of 15 mg/mmol has CKD G4A2.

    • A person with an eGFR of 50 ml/min/1.73 m2 and an ACR of 35 mg/mmol has CKD G3aA3.

  • An algorithm is available to help healthcare professionals understand how the category of CKD should determine the next steps for management (see algorithm B in the NICE resources for local practice).

  • Raised ACR is a powerful independent marker of the risk of adverse outcomes in CKD, and the use of ACR and GFR in combination will allow better risk stratification.

2.4 Further resources

Further resources are available from NICE that may help to support implementation.

A clinical knowledge summary on chronic kidney disease (not diabetic) is available with details of the evidence and guidance for primary care.

The National Chronic Kidney Disease Audit pilot (December 2014) aims to improve diagnosis in primary care, to understand the standard of patient care and map its variation, and to drive improvements using electronic patient management systems.

NICE produces indicators annually for use in the Quality and Outcomes Framework (QOF) for the UK. The process for this and the NICE menu are available.

Uptake data about guideline recommendations and quality standard measures are available on the NICE website.

  • National Institute for Health and Care Excellence (NICE)