Impact of Using Risk-Based Stratification on Referral of Patients With Chronic Kidney Disease From Primary Care to Specialist Care in the United Kingdom

Introduction: The externally validated Kidney Failure Risk Equation (KFRE) for predicting risk of end-stage
renal disease (ESRD) has been developed, but its potential impact in a population on referrals for patients
with chronic kidney disease (CKD) from primary to specialty nephrology care is not known.
Methods: A cross-sectional population-based study of individuals in United Kingdom primary care
registered in The Health Improvement Network database was conducted. National Institute of Health and
Care Excellence (NICE) 2014 CKD guidelines versus the 4-variable KFRE set at a >3% risk of ESRD at 5
years were applied to patients identified with CKD stage 3-5 between January 1, 2016, and March 31, 2017.
Results: In all, 39,476 (36.6%) of 107,962 adults with CKD stage 3-5 had a urine albumin:creatinine ratio
(ACR) available and entered into the primary analysis. Of that, 7566 (19.2%) patients fulfilled NICE criteria
for referral, 2386 (31.5%) of whom had a #3% 5-year risk of ESRD. Also 8663 (21.9%) patients had a >3%
5-year risk of ESRD, 3483 (40.2%) of whom did not fulfill NICE criteria; this represents 8.8% of the primary
population. By using the KFRE threshold rather than NICE criteria for referral, 5869 patients (14.9% of the
primary analysis population) would have been reallocated between primary and specialist care. Imputa�tional analysis was used for missing ACR measurements and showed similar results.
Conclusions: A risk-based referral approach would lead to a substantial reallocation of patients between
primary care and specialist nephrology care with only a small increase in numbers eligible, ensuring those
at higher risk of progression are identified.