Dr Kathryn Griffith summarises some key findings from the National CKD audit and explains why the NICE quality standard should lead to improvements in care

griffith kathryn edited

Dr Kathryn Griffith

20160729 independent content logo with text (rgb)

Read this article to learn more about:

  • the current state of care for people with, or at risk of, chronic kidney disease (CKD) in the UK
  • using estimated glomerular filtration rates and albumin:creatinine ratios to measure CKD severity
  • why it is important to monitor blood pressure and offer statins to people with CKD.

Key points

Commissioning messages

Chronic kidney disease (CKD), as we now recognise it, was defined in 2002 when a group of nephrologists in North America recommended new methods to identify people with kidney disease at an earlier stage of the disease, as part of the Kidney disease improving global outcomes initiative.1,2

Since then, the UK has seen:

  • the introduction of routine reporting of estimated glomerular filtration rate (eGFR)
  • a National Service Framework for Renal Services, introduced in 20043
  • inclusion of CKD in the quality and outcomes framework (QOF)4
  • publication in 2008 of NICE Clinical Guideline (CG) 73 Chronic kidney disease: early identification and management of chronic kidney disease in adults in primary and secondary care, replaced in 2014 by NICE CG182 Chronic kidney disease in adults: assessment and management5
  • publication in 2011 of NICE Quality Standard (QS) 5 Chronic kidney disease in adults, last updated in July 2017.6

This article discusses the importance of identification of CKD and the impact on management. The high-priority areas for quality improvement defined by NICE QS5 will be described,6 and the importance of quality and audit will be reinforced with supporting evidence from the National CKD audit in primary care.7

Diagnosis of CKD

Prevalence of CKD increases with age. In a UK population study the age-standardised prevalence of people with an eGFR of less than 60 ml/min/1.73m2 (CKD stages 3–5) was calculated at 8.5%, with higher prevalence in females (10.6%) compared with males (5.8%).8

Estimated glomerular filtration rate (eGFR) testing

The introduction of eGFR has provided GPs with a convenient way to assess the efficiency of kidney function. Before this, an accurate value could only be obtained by hospital-based clearance tests.

The eGFR test uses measurement of creatinine levels and a calculation derived from the Modification of diet in renal disease (MDRD) study.9,10 Using this test, it is possible to classify the CKD by stage and justify the label ‘chronic’ if the abnormalities have been present for more than 3 months.

There are some innate inaccuracies involved with a test using creatinine measurements. The most obvious one is that serum creatinine level is related to other factors not associated with kidney function, for example, muscle mass, consumption of cooked meat, and some medications.

There are also concerns that use of the test has led to increased anxiety in patients diagnosed with a ‘disease’, which, in essence, is not a disease, and will have little or no impact on life expectancy. This is particularly relevant in older patients; up to 50% of people aged 85 years and older have an eGFR of <60 ml/min/1.73m2.8 A slow fall in eGFR over many years is consistent with ageing; however, the majority of people with significant CKD will also have hypertension and diabetes consistent with pathological processes affecting the kidney.

NICE CG182 recommends that the CKD-EPI equation should be used in preference to MDRD,5 as the CKD-EPI equation reflects a more ‘normal’ population and was expected to produce a more accurate result in borderline cases where there was a concern about over diagnosis. The CKD-EPI equation will give a different result to the MDRD equation in the same patient, reflecting differences in the equation rather than deterioration or improvement of kidney function. The inherent problems with using creatinine levels still apply when using the CKD-EPI equation so there has been concern that there will be more confusion for little gain; therefore, it has not been widely adopted in clinical practice at this stage.

Proteinuria as a measure of kidney damage

An important early sign of kidney damage is the leakage of albumin from the glomerulus. Proteinuria is best assessed using a spot urine sample; NICE CG182 recommends that albumin:creatinine ratio (ACR) should be used in preference to protein:creatinine ratio (PCR).5 Raised ACR levels:5

  • are associated with increased risk of kidney damage, progression of CKD, and increased risk of cardiovascular disease
  • in a younger person, may be caused by glomerulonephritis
  • occurring with a normal (or even high eGFR) are an early marker of diabetic nephropathy associated with hyperfiltration
  • usually occur at a later stage in hypertension, usually after eGFR has fallen.

Table 1 defines the categories used to describe ACR levels. Elevated ACR levels are considered significant for people both with and without diabetes.

A combination of eGFR and ACR is used to more accurately describe a person’s CKD severity (see Table 2).5

Table 1: Categories used to describe ACR levels2
TermACR categoryACR (mg/mmol)Dipstick result

Normal to mildly increased

A1

<3

Negative

Moderately increased

A2

3–30

Negative

Severely increased

A3

>30

+

Nephrotic syndrome

>220

+++

ACR=albumin:creatinine ratio

Adapted from NICE. Chronic kidney disease in adults: assessment and management. NICE Clinical Guideline 182. NICE, 2015. nice.org.uk/cg182 and Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2012 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney Inter 2013; 3 (suppl): 1–150.

NICE has not checked the use of its content in this article to confirm that it accurately reflects the NICE publication from which it is taken

Reproduced with permission

 

Table 2: Classification of CKD using GFR and ACR categories2

GFR and ACR categories and risk of adverse outcomes

ACR categories (mg/mmol), description, and range

<3

3–30

>30

Normal to mildly increased

Moderately increased

Severely increased

A1

A2

A3

GFR categories (ml/min/1.73 m2), description, and range

≥90

Normal and high

G1

No CKD in the absence of markers of kidney damage

   

60–89

Mild reduction related to normal range for a young adult

G2

   

45–59

Mild–moderate reduction

G3a*

     

30–44

Moderate–severe reduction

G3b

     

15–29

Severe reduction

G4

     

<15

Kidney failure

G5

     
Key
Green low risk (if no other markers of kidney disease, no CKD)
Yellow moderately increased risk 
Orange  high risk 
Red  very high risk 

*Consider using eGFRcystatinC for people with CKD G3aA1 (see NICE CG182 recommendations 1.1.14 and 1.1.15)

ACR=albumin:creatinine ratio; CKD=chronic kidney disease; GFR=glomerular filtration rate

NICE. Chronic kidney disease in adults: assessment and management. NICE Clinical Guideline 182. NICE, 2015. nice.org.uk/cg182 and Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2012 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney Inter 2013; 3 (suppl): 1–150.

NICE has not checked the use of its content in this article to confirm that it accurately reflects the NICE publication from which it is taken

Reproduced with permission

 

Chronic kidney disease and the QOF

For several years key performance indicators for CKD were reflected in QOF, which adapted over time to cover the important areas of assessment of CKD, including eGFR and ACR monitoring, and blood pressure control (see Table 3).4

Unfortunately, despite the hard work put in by many primary care teams to develop CKD registers and improve detection of and treatment for CKD, the clinical indicators were removed from the QOF in the 2015/16 version.

Table 3: Chronic kidney disease indicators in the 2014/2015 quality and outcomes framework4
IndicatorPointsAchievement thresholds

Records

   

CKD001. The contractor establishes and maintains a register of patients aged 18 or over with CKD (US National Kidney Foundation: Stage 3 to 5 CKD)

6

 

Ongoing management

   

CKD002. The percentage of patients on the CKD register in whom the last blood pressure reading (measured in the preceding 12 months) is 140/85 mmHg or less

11

41-81%

CKD003. The percentage of patients on the CKD register with hypertension and proteinuria who are currently treated with an ACE-I or ARB

9

45–80%

CKD004. The percentage of patients on the CKD register whose notes have a record of a urine albumin:creatinine ratio (or protein:creatinine ratio) test in the preceding 12 months

6

45–80%

Healthcare Quality Improvement Partnership (HQIP) National CKD audit

In 2014 a pilot phase of the National CKD audit was launched, funded by NHS England and the Welsh Government as part of the National Clinical Audit and Patient Outcomes Programme.7,11 The purpose of the project was to improve care for people with CKD by auditing against NICE QS5, and to support targeted quality improvement activity using software integrated into patient consultations.

Data was collected from 911 practices in the project reflecting a population of 5.2 million adults. This included 70% of Welsh and 7.5% of English practices, including a wide mix of urban and rural practices and ethnicities. Over 1.5 million people who had either CKD or risk factors for CKD were involved in the study.

Initially, the aim was to invite all practices in England and Wales to participate and provide data in routine data collection and therefore develop local and national reports to gain an understanding of key performance indicators for care of people with and at risk of CKD, and understand variations in care. Unfortunately, free access to the required software did not materialise, limiting participating practices to those with existing paid access to the system. Despite this setback, the pilot still provides the largest primary care database for CKD in the world.

Recording Read codes for CKD

There was wide variation between practices in the rates of coding for CKD, including issues with miscoding. Important findings from the report showed that:12

  • 4.17% of people aged over 18 years were coded with CKD stages 3–5:
    • in 11% of these cases, the two most recent eGFRs more than 3 months apart were >60 ml/min/1.73m2 and had therefore been miscoded, using historical rather than recent data
    • other patients were miscoded because appropriate correction factors for ethnicity had not been used
  • only 69.8% of people with biochemical evidence for CKD (i.e. two eGFR values of <60ml/min/1.73m2) had a CKD Read code.

Repeat eGFR and ACR testing

NICE CG182 recommends that people with established CKD should be reviewed at least annually, and that the review should include eGFR and ACR checks (see Table 4).5 Results from the National CKD audit showed that while rates of annual testing for eGFR were relatively high (>90% in people with diabetes; ~80% in people without diabetes), rates of ACR testing were variable (60% in people with diabetes, 10% without diabetes).12

This reflects many factors but particularly the lack of understanding of the importance of ACR testing and/or an apparent dislike of urine sampling.

 

Table 4: Frequency of monitoring of GFR (number of times per year, by GFR and ACR category) for people with, or at risk of, chronic kidney disease2
 

ACR categories (mg/mmol), description, and range

A1

A2

A3

<3

3–30

>30

Normal to mildly increased

Moderately increased

Severely increased

GFR categories (ml/min/1.73 m2), description, and range

G1

≥90

Normal and high

≤1

1

≥1

G2

60–89

Mild reduction related to normal range for a young adult

≤1

1

≥1

G3a

45–59

Mild–moderate reduction

1

1

2

G3b

30–44

Moderate–severe reduction

≤2

2

≥2

G4

15–29

Severe reduction

2

2

3

G5

<15

Kidney failure

4

≥4

≥4

Key
Green stable disease, with follow up measurements annually if CKD is present
Yellow requires caution and measurements at least once per year 
Orange  requires measurements up to twice per year
Red  requires measurements up to 3 times per year 
Dark red  requires closest monitoring approximately 4 times or more per year (at least every 1–3 months)

ACR=albumin creatinine ratio; GFR=glomerular filtration rate

ACR is an important indicator of cardiovascular risk and progression

NICE. Chronic kidney disease in adults: assessment and management. NICE Clinical Guideline 182. NICE, 2015. nice.org.uk/cg182 and Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2012 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney Inter 2013; 3 (suppl): 1–150.

NICE has not checked the use of its content in this article to confirm that it accurately reflects the NICE publication from which it is taken

Reproduced with permission

Testing people at risk of CKD

The National CKD audit assessed the number of people at risk who had the relevant tests for CKD and found that:12

  • in people with diabetes—
    • 86% had an annual blood test for eGFR
    • 54% had an annual urine test for ACR
  • in people with hypertension—
    • 95% had a blood test for eGFR in a 5-year period
    • 28% had a urine test for ACR in a 5-year period.

Finding raised ACR levels is a marker of increased risk and would signal the need for angiotensin–aldosterone system [RAAS] antagonists.

Management of CKD

The audit also examined aspects of management of CKD including blood pressure (BP) control and treatment with statins, both of which are important strategies for reducing the risk of cardiovascular events.

The results showed wide variation, perhaps reflecting a lack of confidence in or understanding of the importance of these key parameters, despite their inclusion in the QOF at the time of the audit.

Blood pressure control

NICE CG182 recommends blood pressure targets of:5

  • <140/90 mmHg in people with CKD
  • <130/80 mmHg in people with CKD and diabetes, and also in people with an ACR of ≥70 mg/mmol.

Practices achieved the higher blood pressure target (for CKD without diabetes or heavy proteinuria) in 53% of their patients, whereas the lower target (for CKD with diabetes or heavy proteinuria) was achieved in only 29% of cases.

Treatment with statins

NICE CG181 on Cardiovascular disease: risk assessment and reduction including lipid modification published in 2014, recommends that people with CKD should be offered atorvastatin 20 mg for the primary or secondary prevention of cardiovascular disease (CVD).13

The audit found that 69% of people with CKD had been prescribed statin medication, many of whom were likely to have had coexisting coronary disease, diabetes, and hypertension.12 Only 41% of people aged 65 years or under without diabetes but with CKD, were prescribed statin medication.

Future reports

More data will be available soon as a second report on the National CKD audit is due to be published in January 2018. The data demonstrate strong links between CKD and outcomes, in particular unplanned admissions and mortality. Late presentation of people with kidney failure increases morbidity, mortality, and associated healthcare costs.1 Clinical commissioning groups could use this information about CKD in systems that have been developed to identify and review high-risk patients. Patients who have CKD and are uncoded may be at higher risk, and this aspect continues to be studied.

Why do we need an updated quality standard for CKD?

It is clear from the results of the National CKD audit that there are still variations in the identification and coding of CKD and the provision and quality of care in people with a confirmed diagnosis of CKD.

NICE QS5 was first published in 2011 and contained 10 quality statements, the majority of which were relevant to primary care.6 Although they were considered desirable aspects of care, performance was difficult to measure. In July 2017, NICE QS5 was updated to reflect findings from the National CKD audit and loss of the CKD clinical indicators from the QOF.6 The number of statements was reduced to just three, focusing on the most significant areas for improvement (see Table 5).

Table 5: NICE quality standard for Chronic kidney disease—list of quality statements6
No.Quality statement

1

Adults with, or at risk of, CKD have eGFRcreatinine and ACR testing at the frequency agreed with their healthcare professional.

2

Adults with CKD have their blood pressure maintained within the recommended range.

3

Adults with CKD are offered atorvastatin 20 mg.

CKD= chronic kidney disease; eGFR=estimated glomerular filtration rate; ACR=albumin:creatinine ratio

NICE. Chronic kidney disease in adults. Quality Standard 5. NICE, 2011 (updated 2017). Available at: nice.org.uk/qs5

NICE has not checked the use of its content in this article to confirm that it accurately reflects the NICE publication from which it is taken

Reproduced with permission.

Identifying and monitoring—quality statement 1

NICE CG182 makes recommendations on the frequency of monitoring (eGFR and ACR) for people with, or at risk of, CKD based on:5

  • the underlying cause of CKD
  • past patterns of eGFR and ACR (but be aware that CKD progression is often nonlinear)
  • comorbidities, especially heart failure
  • changes to their treatment (such as renin–angiotensin–aldosterone system [RAAS] antagonists, non-steroidal anti-inflammatory drugs [NSAIDs] and diuretics)
  • intercurrent illness
  • whether they have chosen conservative management of CKD.

Retesting is recommended at least annually for people with established CKD and more frequently for those with more advanced stages (see Table 3). If the patient becomes unwell and at risk of acute kidney injury (AKI) then additional testing should be arranged and changes to medication or doses should be considered.

For certain at-risk groups (for example, people with connective tissue disorders who attend rheumatology clinics, or people with structural renal disease attending urology clinics), frequency of testing may need to be decided with input from other healthcare professionals.

Frequency of testing in people at risk of CKD should be established on an individual basis but planned by the professional and understood by the patient.5 Adults at risk of CKD are specified as those with any of the following risk factors:5,6

  • diabetes
  • hypertension
  • acute kidney injury
  • cardiovascular disease (ischaemic heart disease, chronic heart failure, peripheral vascular disease, or cerebrovascular disease)
  • structural renal tract disease, recurrent renal calculi, or prostatic hypertrophy
  • multisystem diseases with potential kidney involvement—for example, systemic lupus erythematosus
  • family history of end-stage kidney disease (GFR category G5) or hereditary kidney disease—for example, autosomal dominant polycystic kidney disease
  • opportunistic detection of haematuria
  • prescribed drugs which impact on kidney function such as calcineurin inhibitors (for example, cyclosporin or tacrolimus), lithium, and NSAIDs.

It is hoped that quality statement 1 will enable earlier detection of CKD and help to reduce the risk of progression, cardiovascular disease, and unplanned hospital admission. The importance of ACR testing is reinforced as it is placed at equal priority with eGFR testing in the statement.

Blood pressure control—statement 2

People with CKD are at increased risk of hypertension. This statement reflects the importance of individualising blood pressure control to the patient’s level of CKD, ACR levels, and other co-morbidities as recommended in the guidance.

It is hoped to reinforce the fact that, despite removal from the QOF, blood pressure measurement remains an extremely important part of clinical care in people with CKD and that audit is recommended to demonstrate quality care.

Statins for people with CKD—statement 3

Cardiovascular disease is associated with high premature mortality rates, and people with CKD are at higher risk of CVD.14 Statement 3 is new for 2017 and reflects the importance of reducing the risks associated with CVD in people with CKD.

NICE CG181 (on cardiovascular disease) makes the following recommendations specific to CKD:13

  • do not use a risk assessment tool to assess CVD risk in people with an estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73m2 and/or albuminuria. These people are at increased risk of CVD
  • offer atorvastatin 20 mg for the primary or secondary prevention of CVD to people with CKD—
    • increase the dose if a greater than 40% reduction in non-HDL cholesterol is not achieved … and eGFR is 30 ml/min/1.73m2 or more
    • agree the use of higher doses with a renal specialist if eGFR is less than 30 ml/min/1.73m2.

Preliminary evidence from clinical trials suggests that people with CKD gain benefit from statins, just like people with normal kidney function. Atorvastatin is the statin of choice because of its effectiveness at lowering low density lipoprotein, but care should be taken in patients with declining kidney function because of increasing risk of side-effects.

Conclusion

It could be argued that the updated NICE QS5 just reflects ‘more of the same’, and in the context of the loss of CKD from the QOF that is correct. By detailing results of the National CKD audit, the author hopes to have demonstrated that the quality statements reflect key performance indicators identified in the audit, and that detection and diagnosis of CKD could be used as a helpful tool in primary care management for some time to come.

Key points

  • Prevalence of CKD increases with age; the prevalence of people with CKD stages 3–5 has been calculated at 10.6% (females) and 5.8% (males)
  • eGFR tests use measurement of creatinine levels with a calculation to classify the stage of CKD
  • A slow fall in eGFR over many years is consistent with ageing; however, most people with significant CKD will also have hypertension and diabetes consistent with pathological processes affecting the kidney
  • Leakage of albumin from the glomerulus is an important early sign of kidney damage:
    • NICE CG182 recommends that albumin:creatinine ratio (ACR) testing should be used in preference to protein:creatinine ratio (PCR) testing
    • raised ACR levels are considered significant for people both with and without diabetes
  • A combination of eGFR and ACR is used to more accurately describe a person’s CKD severity
  • The National CKD audit was launched in 2014 to improve care for people with a confirmed diagnosis of CKD:
    • wide variation was found between practices in the identification, rates of coding, and provision and quality of care of people with CKD
    • rates of annual testing for eGFR were relatively high but rates of annual testing for ACR were variable
  • Management of people with CKD should include:
    • blood pressure control to recommended targets
    • treatment with statins
  • Recent data have shown strong links between CKD and outcomes, particularly in unplanned admissions and mortality:
    • clinical commissioning groups could use this information in systems to identify and review high-risk patients
  • NICE Quality Standard 5 was updated to focus on the most significant areas for improvement: its quality statements reflect key performance indicators identified in the National CKD audit.

Back to top

GP commissioning messages

  • The National CKD audit has shown that there are still significant improvements that can be made in the care of people with CKD
  • This clinical area has been found to be quite complicated for GPs to understand easily
  • There is evidence that people with CKD are at higher risk for complications such as AKI, complications elated to medications and unplanned hospital admission
    • therefore low eGFR is a marker for increased risk and patients who may need assessment to reduce hospital admission
  • ACR remains important as a marker for early diabetic nephropathy and increased risk in CKD
  • Targets for the management of CKD in line with NICE guidance, including blood pressure and urinalysis, no longer appear in the QOF, so some incentives to manage this condition effectively have been lost:
    • commissioners should consider conducting local audits of the management of CKD and support practices to ensure patients are effectively monitored and treated.

CKD=chronic kidney disease; AKI=acute kidney injury; QOF=quality and outcomes framework

Back to top

References

  1. National Kidney Foundation. K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification and stratification. Am J Kidney Dis 2002; 43 (suppl 1): S1–266.
  2. International Society of Nephrology website. Kidney disease improving global outcomes (KDIGO) www.theisn.org/kidney-disease-improving-global-outcomes-kdigo (accessed 22 November 2017).
  3. Department of Health (DH) Renal Team. National service framework: kidney disease. DH, 2004. Available at: www.gov.uk/government/publications/national-service-framework-kidney-disease
  4. NHS Employers. 2014/15 General medical services (GMS) contract quality and outcomes Framework (QOF): guidance for GMS contract 2014/15. NHS Employers, 2014. Available at: www.nhsemployers.org/~/media/Employers/Publications/2014%2015%20QOF%20guidance%20stakeholders.pdf
  5. NICE. Chronic kidney disease in adults: assessment and management. Clinical Guideline 182. NICE, 2014 (updated 2015). Available at: nice.org.uk/cg182
  6. NICE. Chronic kidney disease in adults. NICE Quality Standard 5. NICE, 2011 (updated 2017). Available at: nice.org.uk/qs5
  7. National CKD audit website. www.ckdaudit.org.uk (accessed 22 November 2017).
  8. Stevens P, O’Donoghue D, de Lusignan S et al. Chronic kidney disease management in the United Kingdom: NEOERICA project results. Kidney Int 2007; 72 (1): 92–99.
  9. Klahr S, Levey A, Beck G et al. The effects of dietary protein restriction and blood-pressure control on the progression of chronic renal disease. N Engl J Med 1994; 330 (13): 877–884.
  10. National Institute of Diabetes and Digestive and Kidney Diseases. Estimating glomular filtration rate. www.niddk.nih.gov/health-information/communication-programs/nkdep/laboratory-evaluation/glomerular-filtration-rate/estimating (accessed 22 November 2017).
  11. Healthcare Quality Improvement Partnership website. National chronic kidney disease audit. www.hqip.org.uk/national-programmes/a-z-of-nca/kidney-chronic-kidney-disease-in-primary-care (accessed 22 November 2017).
  12. Nitsch D, Caplin B, Hull S, Wheeler D. National chronic kidney disease audit—national report (part 1). Healthcare Quality Improvement Partnership, 2017. www.hqip.org.uk/resources/national-chronic-kidney-disease-audit-national-report-part-1/
  13. NICE. Cardiovascular disease: risk assessment and reduction including lipid modification. Clinical Guideline 181. NICE, 2014 (updated 2016). Available at: nice.org.uk/cg181
  14. Go A, Chertow G, Fan D et al. Chronic kidney disease and the risk of death, cardiovascular events and hospitalization. N Eng J Med 2004; 351 (13): 1296–1305.