Use of the kidney failure risk equation: a regional retrospective primary care cohort study in England

Chronic kidney disease (CKD) is associated with increased risk of death and progression to kidney failure requiring renal replacement therapy (RRT). Predicting those at greatest risk of RRT is essential for effective clinical care. The kidney failure risk equation (KFRE) is useful for predicting risk of RRT but does not consider the competing risk of death.

To measure the association between KFRE scores and probability of death versus RRT; and to quantify the number of patients with a KFRE score >5%.

Retrospective cohort study conducted from 2018 to 2023 using the primary care Greater Manchester Care Record.

A mixed descriptive and regression analyses. Multinomial regression was used to measure the association between KFRE score categories (<5%, 5%-20%, and >20%) and relative risk/probability of death and RRT.

In general, for the KFRE category of <5%: probability of RRT was 0.1% (95% confidence interval [CI] = 0.1 to 0.2) and death was 11.9% (95% CI = 11 to 13); for the KFRE category 5%-20%: probability of RRT was 2% (95% CI = 1 to 3) and death was 23% (95% CI = 20 to 27); and for the KFRE category of >20%: probability of RRT was 14% (95% CI = 8 to 23) and death was 29% (95% CI = 25 to 36). On average, 11% of patients with CKD stages 3-5 had a KFRE score >5% and could be eligible for referral to nephrology.

The probability of death was generally greater than RRT across KFRE categories - useful for clinicians to consider in shared decision making and management. An estimate of all patients potentially eligible for referral to nephrology is useful for care delivery and provision of nephrology services.