ASN's Mission

ASN leads the fight to prevent, treat, and cure kidney diseases throughout the world by educating health professionals and scientists, advancing research and innovation, communicating new knowledge, and advocating for the highest quality care for patients.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005


The Latest on Twitter

Kidney Week

Abstract: PO0537

Validation and Comparison of the Kidney Failure Risk Equation and a Novel Risk Calculator in Advanced CKD

Session Information

Category: CKD (Non-Dialysis)

  • 2102 CKD (Non-Dialysis): Clinical, Outcomes, and Trials


  • Thanabalasingam, Susan Jeevana, Kingston Health Sciences Centre, Kingston, Ontario, Canada
  • Norman, Patrick Alexander, Kingston Health Sciences Centre, Kingston, Ontario, Canada
  • Day, Andrew G., Kingston Health Sciences Centre, Kingston, Ontario, Canada
  • Akbari, Ayub, Ottawa Hospital, Ottawa, Ontario, Canada
  • Iliescu, Eduard A., Kingston Health Sciences Centre, Kingston, Ontario, Canada
  • White, Christine A., Kingston Health Sciences Centre, Kingston, Ontario, Canada

The Kidney Failure Risk Equation (KFRE) is a widely used clinical tool for predicting risk of CKD G3-5 progressing to end-stage kidney disease (ESKD). A novel calculator (Grams) was developed for G4+ patients to predict ESKD, CVD events and death. The Grams model has not been externally validated. We aimed to assess this new tool in a cohort of advanced CKD patients for ESKD prediction and compare it to the KFRE.


This retrospective cohort study included 444 adult CKD G4+ patients (mean age 73 ± SD 12; mean eGFR 19.6 ± 6.1). The 2- and 5-year KFRE and 2 and 4-year Grams scores were compared in terms of discrimination and calibration (4 ESKD risk intervals <10%,10-20%, 20-40% and >40% ). Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of KFRE-2 and Grams-2 were reported using 10% and 20% thresholds.


Both models had similar discrimination for ESKD risk at the 2-(KFRE-2 AUC 0.82, 95% CI 0.80–0.87, Grams-2 AUC 0.80, 95% CI 0.75–0.86), 4-(Grams-4 AUC 0.81, 95% CI 0.77–0.86) and 5-year (KFRE-5 AUC 0.80, 95% CI 0.76–0.84) timepoints. Both were well calibrated with observed risk at predicted intervals of <10% and 10-20% at 2 years and <10%, 10-20% and 20-40% intervals at 4 and 5 years (Figure 1). Grams-2 under-predicted while KFRE-2 over-predicted risk at higher intervals (20-40% and >40%). KFRE-2 and Grams-2 had adequate sensitivity, performing similarly at ESKD risk thresholds of 10% (p=0.71) and 20% (p=0.48) (Table 1). Both had poor specificity and low PPVs at both thresholds.


The KFRE and Grams models perform similarly at lower ranges of risk in CKD G4+. The KFRE and Grams models however overestimate and underestimate risk respectively at higher risk intervals.

Figure 1

Table 1