# Estimates of eskd risk and timely kidney replacement therapy education

## TL;DR

This study compares how doctors' estimates of kidney failure risk affect referrals for kidney replacement therapy education compared to a mathematical formula.

## Contribution

The study reveals that physicians' overestimation of kidney failure risk does not lead to higher referrals for kidney replacement therapy education.

## Key findings

- Only a fifth of patients were referred for KRT education within 90 days.
- KFRE-based referrals showed higher sensitivity but lower specificity compared to physician estimates.
- Physicians' high-risk predictions did not result in higher referral rates for KRT education.

## Abstract

Kidney replacement therapy (KRT) needs preparation and its timing is difficult to predict. Nephrologists’ predictions of kidney failure risk tend to be more pessimistic than the Kidney Failure Risk Equation (KFRE) predictions. We aimed to explore how physicians’ risk estimate related to referral to KRT education, vs. the objective calculated KFRE.

Prospective observational study of data collected in chronic kidney disease (CKD) clinics of the Veterans Affairs Medical Center San Diego and the University of California, San Diego. The study included 257 participants who were aged 18 years or older, English speaking, prevalent CKD clinic patients, with estimated glomerular filtration rate (eGFR) < 60 mL/min per 1.73 m2 (MDRD equation). The exposure consisted of end stage kidney disease (ESKD) risk predictions. Nephrologists’ kidney failure risk estimations were assessed: “On a scale of 0–100%, without using any estimating equations, give your best estimate of the risk that this patient will need dialysis or a kidney transplant in 2 years.” KFRE was calculated using age, sex, eGFR, serum bicarbonate, albumin, calcium, phosphorus, urine albumin/creatinine ratio. The outcomes were the pattern of referral to KRT education (within 90 days of initial visit) and kidney failure evaluated by chart review. The population was divided into groups either by nephrologists’ predictions or by KFRE. Referral to KRT education was examined by group and sensitivity and specificity were calculated based on whether participants reached kidney failure at 2 years.

A fifth were referred for education by 90 days of enrollment. Low risk patients by both estimates had low referral rates. In those with nephrologists’ predictions ≥ 15% (n = 137), sensitivity was 71% and specificity 76%. In those with KFRE ≥ 15% (n = 55), sensitivity was 85% and specificity 41%.

Although nephrologists tend to overestimate patients’ kidney failure risk, they do not appear to act on this overestimation, as the rates of KRT education referrals are lower than expected when a nephrologist identifies a patient as high risk.

Not applicable

The online version contains supplementary material available at 10.1186/s12882-024-03687-8.