There is not enough evidence to recommend different approaches to measurements of kidney function in black, Asian and other minority ethnic groups, NICE has concluded.
In its update to assessment and management of chronic kidney disease, the committee said it had agreed to remove the 2014 recommendation on how to adjust the CKD-EPI creatinine equation for adults of African-Caribbean or African family origin.
This is because a detailed review of the evidence had found that adding an ethnicity adjustment to eGFR equations for different ethnicities may not be valid or accurate.
Studies had not been done on UK populations which may differ from those for example in the US, and ethnicity adjustments do not factor-in people with mixed ethnicity, of whom the UK has a large population, the committee said while issuing strong recommendations that more research be done.
The updated recommendations also note that ethnicity should not be a risk factor to indicate testing for CKD in itself along with age or obesity in the absence of other factors such as diabetes or hypertension.
Other new recommendations include use of urine albumin-creatinine ratio rather than protein-creatinine ratio and the adoption the 4-variable Kidney Failure Risk Equation for referrals.
Patients should be referred if they have a five-year risk of needing renal replacement therapy of greater than 5%, NICE said, but there may be an implementation period before this risk calculation is available to all GPs.
GPs should also consider discussing management with a specialist by letter, email, telephone, or virtual meeting, if there are concerns but the person with CKD does not need a referral, NICE said.
And the frequency of monitoring in adults, children or young people with or at risk of CKD, should be agreed with them or their carers ‘bearing in mind that the condition is not progressive in many people’, the recommendations note.
Recommendations on managing high blood pressure in patients with CKD have been updated to be in line with NICE hypertension guidelines.
In adults with CKD and an ACR under 70 mg/mmol, clinicians should aim for a clinic systolic blood pressure below 140 mmHg (target range 120 to 139 mmHg) and a diastolic blood pressure below 90 mmHg.
And in those with an ACR of 70 mg/mmol or more, a clinic systolic blood pressure below 130 mmHg (target range 120 to 129 mmHg) and diastolic below 80 mmHg.
The guidance also includes advice on the use of SGLT2 inhibitors but states that this may change as a result of an upcoming evidence review on the drugs.
Why the committee made its recommendations
Evidence on the specific eGFR equations or ethnicity adjustments seen by the committee was not from UK studies so may not be applicable to UK black, Asian and minority ethnic groups. None of the studies included children and young people.
The committee agreed that adding an ethnicity adjustment to eGFR equations for different ethnicities may not be valid or accurate.
Categorisations based on ethnicity lump together people with a diverse range of family backgrounds and differences in eGFR across ethnicities are likely to at least partly arise because of differences in average muscle mass between ethnic groups.
However, muscle mass also differs from person to person within the same ethnicity and so making an adjustment based on ethnicity may be inaccurate for some people.
Therefore, the committee agreed to remove the 2014 recommendation on how to adjust the CKD-EPI creatinine equation for adults of African-Caribbean or African family origin.