MO483: Validation of The Kidney Failure Risk Equation in a Portuguese Cohort

Abstract

BACKGROUND AND AIMS In chronic kidney disease (CKD) patients, the risk of kidney replacement therapy (KRT) is highly variable. In 2011, Tangri et al. developed the kidney failure risk equations (KFRE) to predict the 2- and 5-year probability of requiring kidney replacement therapy (KRT). The KFRE is an easily calculated 4-variable equation that has been extensively validated in multiple cohorts. The aim of this study was to validate this risk score in a Portuguese cohort. METHOD We conducted a retrospective analysis of CKD patients stage 3–5 referred for nephrology consult at Centro Hospitalar Universitário Lisboa Norte during the first 6 months of 2018. Age, gender, estimated glomerular filtration rate (eGFR) and albuminuria were assessed. The four-variable Kidney Failure Risk Equation (KFRE) calibrated for a non-North American population was calculated. Requirement for KRT was assessed in a 2-year follow-up. We assessed the Cox logistic regression method of the KFRE to predict KRT requirement, and the discriminatory ability was determined using the receiver operating characteristic (ROC) curve. A cut-off value was defined as that with the highest validity. RESULTS A total of 360 patients were included, and 54.4% were male. The mean age was 74.9 ± 12.2 years, serum creatinine was 1.97 ± 0.84 mg/dL, eGFR was 33.4 ± 12.13 mL/min/1.73 m2 and albuminuria was 571.1 ± 848.3 mg/g. The mean calculated risk score was 6.2 ± 11.2%. A total of 23 patients required KRT (6.4%) in the 2-year follow-up. The hazard ratio was 1.1 [95% confidence interval (95% CI) 1.06–1.12; P < .001] for the 2-year risk of KRT. The KFRE predicted progression to KRT requirement with an auROC of 0.903, (95% CI 0.86–0.95; P < 0.001), with a sensitivity of 91.3% and specificity of 71.8%. The optimal KFRE cut-off was >4.5% for 2-year nephrologist referral, with a hazard ratio of HR 26.7 [95% CI 6.15–116.3; P < .001] for 2-year risk of KRT. requirement. CONCLUSION We have independently externally validated the 2-year KFRE and shown that it has excellent discrimination. The KFRE should be incorporated into the clinical care of patients with CKD to improve patient-clinician dialogue and provide guidance on the timing of referral for nephrology evaluation and planning for dialysis access.