Chronic kidney disease and automatic reporting of estimated glomerular filtration rate: revised recommendations

Abstract

Since publication of the Australasian Creatinine Consensus Working Group's position statement in 2005, most Australasian laboratories now automatically report an estimated glomerular filtration rate (eGFR) (based on the Modification of Diet in Renal Disease [MDRD] formula) with results of serum creatinine tests in adults. Anecdotal evidence suggests that automatic reporting of eGFR helps to identify asymptomatic kidney dysfunction at an earlier stage and to develop rational and appropriate management plans. Changes to the measurement and calibration of serum creatinine assays and issues regarding implementation of eGFR in clinical practice led the Australasian Creatinine Consensus Working Group to reconvene in 2007. The recommendations contained here build on the original 2005 position statement and consolidate the role of eGFR in clinical practice. The Working Group recommends that the eGFR upper reporting limit be extended to 90 mL/min/1.73 m2, with eGFR values above this amount being reported as “> 90 mL/min/1.73 m2”, rather than as a precise figure. The Working Group has concluded that it is currently premature to recommend age‐related decision points for eGFR. However, it is appropriate to advise medical practitioners that, in people aged ≥ 70 years, an eGFR in the range 45–59 mL/min/1.73 m2, if stable over time and unaccompanied by other evidence of kidney damage, may be interpreted as consistent with a typical eGFR for this age group and is unlikely to be associated with chronic kidney disease‐related complications. Pending publication of validation studies, the Working Group recommends that Australasian laboratories continue to automatically report eGFR in Aboriginal and Torres Strait Islander peoples and other ethnic groups. The Working Group supports the use of eGFR to assist drug dosing decision making in general practice.

A review of eGFR reporting after 6 months in practice

“…It was found that eGFR values fell with age, and this has also been previously observed 18. This may also be related to the fact that the population used for the derivatisation of the MDRD formula was aged <70 years 5.…”

“…A higher proportion of women in the older age groups were included in the review. It has been recognised that reduced but stable eGFR values in individuals aged 70+ years may be accepted as typical for this age and may therefore not be associated with CKD complications,18 although this is not consistent with the UK CKD guidance 4…”

Drug therapy management in patients with renal impairment: how to use creatinine-based formulas in clinical practice

“…Despite the limitations, serum creatinine-based formulas are routinely used in daily clinical practice [14–17]. In this paper, we will discuss approaches on how to use serum creatinine-based formulas in daily clinical practice in a well-informed way.…”

“…Therefore, recommended dose changes for most drugs are crude (e.g., halving the dose or changing from twice-a-day regimen to a once-a-day regimen) [14]. One could argue that differences between eGFR and the true GFR will remain without practical consequences as long as they do not result in different renal function categories.…”

Early detection of chronic kidney disease

“…The Scottish Intercollegiate Guideline Network guidelines are broadly similar. 6 The UK guidelines, in common with US, 7 Australian, 8 and international 9 recommendations, all endorse the use of the simplified MDRD equation for estimation of GFR. Together these developments are designed to improve recognition and management of chronic kidney disease, which is expected to reduce the growth in the number of patients requiring renal replacement therapy and those presenting needlessly late in the course of their disease.…”